Where to find links to live PGNs from major tournaments?

Suppose you are running a big/important tournament. You want your games broadcast live on the internet. What do you do?

First, you need the equipment - DGT boards and sets, cables, a laptop with an internet connection plus the associated software which will collect the information from the sets, put into pgn files and send to an IP address or email address at suitable intervals.

Second, you need either your own website set up to accept and display these games on the internet or you need an agreement with somebody like chess24.com that they will host your games on their site so people can follow them.

Once you understand that you also understand the answer to your questions. As you say in your intro TWIC tells you the answer. The pgn data is being sent to the organizer's website and/or an independent host like chess24.com. It is in not broadcast universally.

There are only two ways to get the information.

Contact the organizers to get them to send you the files also (but why should they?)
Write a screenscrape program to extract the data from the hosting site.


I figured it out a few minutes later
Go to Menu at top “game” then “Save: Add New Game”
Add a new tag or title and will show in game list so you can pick which one you want!
Saves markings and you can edit tags and of file after


SCID vs ChessBase - play, analyse, visualization - ubuntu

I suggest that you simply use a browser, and play online at chess.com, lichess.com, or chess24.com. While chess.com and chess24.com have paid versions too, all three have the ability to create an account, and play online, including against computers.

You also have the option to use online engines to analyze your games.


What is the Universal Rating System (URS)?

The Universal Rating System is an alternate rating system which, according to the project's web site:

The Universal Rating System™ (URS™ for short), is a revolutionary new
sport’s rating system designed to assess the relative strength of
participants across a wide variety of competitor vs competitor sports
or games.
The URS™ was developed as the result of a collaborative research
project funded by the Grand Chess Tour, the Kasparov Chess Foundation
and the Chess Club and Scholastic Center of Saint Louis.

According to the project's FAQ page, the major differences between URS ratings and FIDE Elo ratings are:

There are many differences between the URS™ and the FIDE system. The
most striking difference is that the URS™ calculates only one rating
for each player, informed by their results at all rates of play. This
published rating is the URS™ system's assessment of each player's
strength at Classical chess (defined as a rate of play where each
player has at least 2 hours for their first 60 moves). The URS™
recognizes that there is useful information about a player's
over-the-board chess strength in all game results regardless of the
time limit, and can therefore more effectively estimate a player's
Classical chess strength by also considering their results at games
played at faster time controls. As the speed of play increases, the
URS™ assigns less and less importance to the game results relative to
games played at slower time controls.
Furthermore, the URS™ is a weighted performance rating, calculated
across several years of previous game results for all players. Older
games are given less importance than more recent games, by applying an
exponential decay rate. Unlike traditional performance ratings, which
are based upon the opponents' rating at the time the game was played,
the URS™ constantly reassesses the strength of all opponents and
searches for the most likely set of current ratings for all players,
in order to best explain the observed results.


How to exploit an opponent's time trouble? (no increment)

Don't try to blitz him by playing fast; now you both are playing without thinking much and you've lost the point of the time advantage.

In general, you should still just try to play the best moves. But if there is any general strategy, it is to avoid forced moves on both sides, so that he has more to consider on every move. Unless it is advantageous, don't start some sequence of captures or checks or an otherwise forced sequence, as he will be able to play a few moves in a row very fast. Keep your threats active and play quiet moves.

If he is really really low on time (like, under a minute), then while your clock is ticking he will probably be looking at a few of your possible moves and trying to come up with a response to each of them that he can play instantly. If you play a different, quiet, move instead, he is likely to waste a few seconds just trying to make sense of it before he can even formulate a good response.


Reti opening with bishop aiming kingside

This is a good question, but I think it could use a slight reformulation:
It's not so much a question of "how can we get our bishop to either d3 or c4", but rather "under which circumstances would the bishop become powerful on those diagonals".

If you're looking for positional ideas to further advance your repertoire in this line, it's often very useful to keep an eye on possible transpositions and openings that lead to analogous structures. For example, in the line you show, black has a very solid Slav structure, arguably even an improved one, since white doesn't have the Qb3 option anymore, so the Bg4 maneuver is perfectly sound. On the other hand, white's position has the same ingredients as most Larsen (1.b3) variants do.

As far as I remember (it's up to you to do the in depth search here), Larsen tended for the e3-f4 (instead of c4) pawn structure whenever he wanted to plant his bishops on b2 and e2. But he did have this Reti type of structure every now and then, see e.g. his game vs Ulf Andersson. So make sure you find out about the positional ideas Larsen used to employ in this system. But for a more extensive search, look into a database and search for all the games where this position has occurred and get inspired by how other players have gone about it. For example I use the TWIC database, I have a collection with many of the older series, and after a quick search I find about 200 games with this exact position.

What Bad_Bishop has suggested to you in his answer is actually a very practical idea, with a relatively clear plan ahead: you're threatening to win the bishop pair, and the weaknesses you may induce in doing so are less important than they seem specially because your weakening of the light squares is coupled with taking away the opponents light square bishop! Although it must be noted that in this specific line, after 9.Nh4, I'd be a bit worried about Be4, as f3 doesn't work due to Nh5. (Make sure you check this variation).

A couple of positional suggestions you might want to consider: (by no means exhaustive, in fact these will be very crude, just to give you some rough ideas)

A conservative approach: stick to the solid pawn structure and double the b2-g7 battery by bringing the queen to a1 or b2 and you coordinate your play around the control of the long diagonal. e.g. a sequence along the lines of: 7.d3 8.Nbd2 9.Re1 10.Qc2 11.Bc3 12.Qb2 etc should get you there... If you're not familiar with such battery ideas on the long diagonal, a good start would be to study this marvelous game by Peter Svidler playing as black: (notice that your pawn structure in this Reti line is completely transposable to that of Svidler's in this game):

-

[FEN ""]
[Event "Dortmund Sparkassen group-A"]
[Site "Dortmund GER"]
[Date "2004.07.26"]
[Round "5"]
[White "Arkadij Naiditsch"]
[Black "Peter Svidler"]
[Result "0-1"]
[ECO "B42"]
[WhiteElo "2574"]
[BlackElo "2727"]
[PlyCount "78"]
[EventDate "2004.07.22"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Bc5 6. Nb3 Be7 7. O-O d6 8. c4 Nf6 9. Nc3 Nbd7 10. f4 Qc7 11. Qe2 b6 12. Bd2 Bb7 13. Rae1 O-O 14. Kh1 g6 15. Nd4 Rfe8 16. Nf3 Rad8 17. Ng5 Bf8 18. Qf2 Bg7 19. b4 Nh5 20. Rc1 Rc8 21. a3 Qd8 22. Nf3 Rc7 23. Rfe1 Nhf6 24. Qh4 Qa8 25. Qh3 Rec8 26. e5 dxe5 27. Nxe5 Nxe5 28. fxe5 Nd7 29. Bf4 Rxc4 30. Bxc4 Rxc4 31. Qg3 h5 32. Ne2 Nxe5 33. Rxc4 Nxc4 34. h4 Qd8 35. Bg5 Qd7 36. Nf4 e5 37. Nd3 Qd5 38. Nf2 Nd6 39. Rd1 Ne4 0-1

Go for the king asap: 7.Nc3 (idea being to force the retake on d5 to be by the e pawn and securing the f5 square for your f3 knight - with a clear attack on the kingside) 8.Nd4 ... Here's an example I could find:

-

[FEN ""]
[Event "70th ch-GER"]
[Site "Bremen GER"]
[Date "1998.11.12"]
[Round "7"]
[White "Hickl, J."]
[Black "Jussupow, A."]
[Result "1-0"]
[ECO "A12"]
[WhiteElo "2540"]
[BlackElo "2640"]
[PlyCount "59"]
[EventDate "1998.??.??"]
[SourceDate "2011.01.01"]

1. c4 c6 2. Nf3 d5 3. e3 Nf6 4. b3 Bg4 5. Bb2 e6 6. Be2 Nbd7 7. Nc3 Bd6 8. Nd4 Bxe2 9. Qxe2 O-O 10. cxd5 exd5 11. Nf5 Bc5 12. Na4 Bb4 13. Nxg7 b5 14. Nf5 bxa4 15. Qh5 Kh8 16. Qg4 Bxd2+ 17. Kxd2 Rg8 18. Qxa4 Rxg2 19. Ke2 Qg8 20. Ng3 Qg6 21. Rac1 Re8 22. Qf4 c5 23. Kf1 Rxg3 24. Bxf6+ Nxf6 25. hxg3 Ne4 26. Rh6 Qg7 27. Rd1 Re5 28. Kg2 Ng5 29. Rc6 h6 30. Rxh6+ 1-0

Transpose to a Queen's gambit decline type of position to secure the d3 square for your bishop: d4, Nbd2, h3, Bd3 ... Here's an example:

-

[FEN ""]
[Event "Golombek Mem"]
[Site "Paignton ENG"]
[Date "2000.09.05"]
[Round "3"]
[White "Bischoff, K."]
[Black "Hillarp Persson, T."]
[Result "1/2-1/2"]
[ECO "A12"]
[WhiteElo "2556"]
[BlackElo "2549"]
[PlyCount "37"]
[EventDate "2000.09.03"]
[SourceDate "2011.01.01"]

1. Nf3 Nf6 2. c4 c6 3. b3 d5 4. Bb2 Bg4 5. e3 e6 6. Be2 Nbd7 7. O-O Bd6 8.d4 O-O 9. Nbd2 Qb8 10. h3 Bh5 11. Bd3 Re8 12. Qc2 a5 13. Rac1 a4 14. Bc3 axb3 15. axb3 Bg6 16. Bxg6 hxg6 17. Ra1 Rxa1 18. Rxa1 e5 19. dxe5 1/2-1/2

Similar to Bad_Bishop's suggestion: start off with h3, make your opponent commit to a decision with the g4 bishop, but instead of an immediate rather committal g4, play the slow game: castles, d3, Nbd2, ... or possibly Nc3 specially if you plan to capture on d5 subsequently: two simple ideas to bear in mind: if black recaptures on d5 with the c-pawn, you want to take control of the c-file asap, if black recaptures with the e-pawn it's often possible to force the exchange of light square bishops in order to secure f5 for your knight. (I admit this is all still very crudely put).
Finally, note that within such Slav structures for black, you'll never see your bishop on c4, it's just incompatible with black's control of the center. Alternatively, if you want your bishop on d3, your best bet is to transpose (as early as possible) into Queen's pawn type of positions. To play openings such as the Larsen, English or the Reti, you really must like slow-positional plays, and in my opinion these are by no means easier to learn/play than open positions, in fact they can get extremely complicated rather quickly. Intuitively, this is because strategic ideas tend to be very abstract and hard to grasp, whereas open positions are more tactical which makes them inherently more concrete. To give you an example of a highly strategic game, played recently, quickly leading to a highly non-trivial middle-game (see the game below). For your purposes I highly recommend studying GM Michael Adams' games in the English opening.

-

[FEN ""]
[Event "GRENKE Chess Classic 2015"]
[Site "chess24.com"]
[Date "2015.02.07"]
[Round "5"]
[White "Adams, Michael"]
[Black "Bacrot, Etienne"]
[Result "1/2-1/2"]
[WhiteElo "2738"]
[BlackElo "2711"]
[PlyCount "129"]
[EventDate "2015.??.??"]

1. c4 Nf6 2. g3 g6 3. Bg2 c5 4. Nc3 Bg7 5. Nf3 O-O 6. d4 cxd4 7. Nxd4 Nc6 8. O-O Qa5 9. Nb3 Qh5 10. Nd5 d6 11. Nf4 Qe5 12. e4 Bg4 13. f3 Bd7 14. Rf2 b5 15. Nd3 Qh5 16. Nf4 Qe5 17. c5 dxc5 18. Nd3 Qc7 19. Nbxc5 Rfd8 20. Qe1 Be8 21. Bf4 e5 22. Be3 a5 23. Rc1 Qe7 24. Rd2 Nd4 25. Nb3 Nd7 26. Nxd4 exd4 27. Bf4 Rdc8 28. Bh3 Rc4 29. Rdd1 a4 30. Bd2 Ne5 31. Nxe5 Qxe5 32. Bf1 Rxc1 33. Bxc1 Qe6 34. a3 Rc8 35. Bd3 Qb3 36. Qe2 Bd7 37. Bf4 Be6 38. h4 Bc4 39. e5 Bxd3 40. Rxd3 Qd5 41. Kg2 h5 42. Qd2 Rc4 43. Qe2 b4 44. axb4 Rxb4 45. Kf2 Qb5 46. Rd2 Qd5 47. Qe4 Qa2 48. Qc2 Kh7 49. Kg2 Qa1 50. Rf2 a3 51. bxa3 Rb1 52. Qd3 Rd1 53. Bd2 Rg1+ 54. Kh3 Rh1+ 55. Rh2 Qg1 56. Qe2 Bxe5 57. f4 Bd6 58. a4 d3 59. Qg2 Rxh2+ 60. Qxh2 Qd1 61. Qg2 Ba3 62. a5 Bc1 63. Qd5 Qf1+ 64. Kh2 Qe2+ 65. Kh3 1/2-1/2


Why is better for white to move Rxa7 instead of Nxd3?

Both rooks control White's back rank. If they are removed through:

Nxd3 Rxa1
Rxa1 Rxa1

Then both pawns cannot be stopped at the same time by the single knight, guaranteeing Black a Queen-Rook endgame. Let's assume White plays Kg2 next:

Kg2 c1=Q
Nxc1 Rxc1

Then the pawn at b3 will surely become a Queen. A worse move but still wins:

Kg2 b2
Nxb2 c1=Q

Because Black still has a Queen and the rook versus White's only minor piece, the Knight.

We also should notice White's passed pawn at d6. So even with d7:

d7 c1=Q+
Nxc1 Rxc1+
Kg2 Rd1

Rd1 prevents White from promoting:

d8=Q+ Rxd8


Have engines refuted any established openings?

No, engines have not refuted any established openings, unless you're including nonsense openings like 1.e4 d6 2. Qg4, which humans already know to be unsound.

In 2012, Rybka's author Vasik Rajlich authored an April's Fool prank in Chessbase claiming to have proved the King's Gambit is at best a draw. Owning up to the prank a few days later, he said:

  It's reasonable to construct a search tree of around 10^18 positions using modern technology. The chess alpha-beta tree is thought to have at least 10^45 positions. The alpha-beta tree for the King's Gambit will be at most 10x to 100x smaller than that. So, we're still probably a good 25 or so orders of magnitude away from being able to solve something like the King's Gambit. If processing power doubles every 18 months for the next century, we'll have the resources to do this around the year 2120, plus or minus a few decades.

The last couple of lines are the most relevant ones. It's 2019 as I write this, so if processing power doubles every 18 months for the next century, we're still a hundred years away from solving the King's Gambit, plus or minus a few decades. The same goes for every other opening, even those 20+ moves long. Talking in terms of order of magnitude, even if the alpha-beta tree for those openings are a billion times (10^9) smaller than chess's, we'd still be a good 16 orders of magnitude or so away from being able to solve it.

If you're also interested in endgames though, then there have been endgames which humans couldn't solve that have been solved by engines (or engines found flaws in human analysis).


Where can I find the saved games or PGN files in the Play Magnus app?

Unfortuately, the Play Magnus app is not capable of creating PGN files. So, when you click on "Export game as PGN file", the game is copied to clipboard. You can then paste the game in a text editor and save it as a PGN file.


Moving into check for a draw as black, why is it illegal? Comparison to Racing Kings

Imagine a variation of chess without the rules about check and checkmate, where a player wins simply when he captures his opponent's king. In this variation, Kxd5 loses the game to exd5.

Turns out, that's more or less how real chess works. The objective is to capture the opponent's king. If your king is under attack, you must deal with that threat. If there's no way to remove the threat, then you lose.

The explicit rule that you must end your move not in check (both by eliminating the check if you're in check, and by not moving into check) and the rule that ends the game with checkmate simply ensure that the king is never actually captured. Check can almost be seen as a safety measure for weaker players who might not notice that their king is under attack. Notice that announcing check is not actually in the rules, and grandmasters never do it. The rule is effectively unnecessary for experts. And checkmate is sort of like the game forcing a resignation when the result is inevitable, much like how experts will resign when they see that their opponent has forced mate.

If we think of the rules of check this way, then it's clear why Kxd5 is illegal: your opponent would take your king, and the fact that his own king becomes exposed is irrelevant because the game is over.


According to this database:

The next move for white will be:

5.e3 with 40% of win, 46% of draw and 14% of lose. (3538 games were played like that)
5.cxd5 with 48.5% of win, 41.5% of draw. (344 games were played like that)

Example for a game which start like this:

[Event "1st Rottal Open 2017"]
[Site "Pfarrkirchen GER"]
[Round "6.1"]
[Date "2017.4.17"]
[White "Haba, Petr"]
[Black "Riediger, Martin"]
[Result "1/2-1/2"]

[FEN ""]
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 g6 5.cxd5 cxd5 6.Bf4 a6 7.h3 Bg7 8.e3 Nc6 9.Be2 O-O 10.O-O Bf5 11.Rc1 Ne4 12.Na4 Bd7 13.Qb3 b5 14.Nc5 Nxc5 15.Rxc5 e6 16.Bd6 Re8 17.Ne5 Nxe5 18.dxe5 f6 19.Bc7 Qe7 20.Bd6 Qd8 21.Bc7 Qe7 22.Bd6 1/2-1/2


What is the Elo rating of a chess computer that can only look 1, 2, 3, ... moves ahead

This is an area that academic can write papers on it. The relationships is complicated and might not be quantified.

Essentially, it's a non-linear relationship where the improvement is most obvious in shallow depth. The benefit diminishes as the engine go deeper and deeper in the search.

Reference: https://chessprogramming.wikispaces.com/Depth

Look for the "Diminishing Returns" section and you'll know more.


Why do they keep the scoresheet in classic chess?

A scoresheet allows for a number of different things.

1. The scoresheet allows reconstruction of the game.

This is important for several reasons. Imagine that an earthquake occurs and upsets the board. (Or, more prosaically, the table was set up incorrectly and is upset by a light touch.) If there is no record, how would you reconstruct the position? Replaying a game simply because of an upset board is a tremendous waste of time, and it's far more mental strain than a player should be expected to handle.

Additionally, with modern storage and retrieval abilities, each game is seen as something to learn from. Every single recorded game is one that can teach us new things.

(Kriegspiel is an instance where it is vital to record the game for reconstruction. Most of the fun is in the post-game discussion, and it's impossible to do this without recording it.)

2. The scoresheet allows for arbitration of disputes.

Without a record, how would you go about proving to an official that 50 moves have occurred without a capture/pawn move? Without a record, how would you prove that your opponent is a scurrilous lout who secretly replaced his Queen on the board while you were in the restroom?

3. The scoresheet is an aid to players in reconstructing their play during the game.

Top chess players are able to remember large numbers of variations and lines. However, having the scoresheet available reduces one aspect of mental accounting: The player can always look at the scoresheet and mentally reproduce the game up to that point, rather than attempting to remember "now was it exd5?"

4. Signing the scoresheet is a way to ensure that both players accept the outcome of the game.

A player's signature is proof that they are satisfied with what happened. It indicates "yes, I played this match, and it happened this way. I agree that this record is accurate."

FIDE devotes section 8 of the Laws of Chess to the scoresheet. Note particularly that 8.7 states:

  At the conclusion of the game both players shall sign both scoresheets, indicating the result of the game. Even if incorrect, this result shall stand, unless the arbiter decides otherwise.


How do you teach chess to a beginner / rookie?

I have a couple of suggestions, some tried and true, others more experimental using modern technology.

1. Start from the endgame

Pros

Starting backwards will allow the player to understand chess at a deep, fundamental level
If you learn the endgame first, you are constantly moving toward a place you are comfortable with when you play the game (as opposed to a middlegame player, who is constantly moving away from his comfort zone)
The endgame is grounded on the concrete, but requires sound positional understanding to play well, thus learning it allows you to learn all aspects of the game

Cons

It can sometimes be tedious to teach and learn the endgame (I'm having this problem myself)
It requires a lot of initial investment from the student, for what seems to be little return (they may get caught by tactics, or opening traps in OTB games, making them discouraged)

2. Teach a thinking algorithm

Basically, create a simple step-by-step process (allow the student to come up with their own and then help them tweak it) which aids in making decisions OTB (i.e moves).

Pros

Very easy to do and has almost immediate results (an anti-blunder check at the end of every move goes a long way to improve one's game)
A fundamental skill which is necessary for every phase of the chess game
Can be built upon as more knowledge about the game is garnered

Cons

None, except for the fact that you aren't focusing on any one thing in particular

3. Tactics, tactics, tactics!

This is more experimental and involves drilling tactical puzzles (I recommend this book, the puzzles are beautifully arranged so that they build on one another) until they can be done "by hand" (i.e directly from memory).

Pros

All the benefits that tactical training provides, including:

Able to handle complex positions with little difficulty
Increase in visualization abilities
Confidence in one's own moves (i.e that they won't be subverted by a missed tactic)
General decrease in blunders and increase in noticing opponents blunders

Memorization of the positions, allows the creation of "building blocks". These are useful because you can often simplify complex positions in these basic blocks
Its just more fun to explore tactical fireworks

Cons

Focusing on just tactics, does not give a true understanding of the game, which is really more important for future success
There is a diminishing return, after which no amount of drilling will help
It can be tedious


If you can play three games blind-folded, it is unlikely that your problem is calculation. I dare say that there aren't many 1900 USCF players that can do that.

You say you "lose a lot of games due to poor evaluation, time pressure, and erratic blunders". That also doesn't cry out "calculation problems" to me.

In my experience ratings first and foremost reflect positional understanding. Calculation skills make a much smaller difference, at least above a certain threshold.

To be clear, positional understanding isn't knowledge as much as a good feeling for the position. I.e. whether you can precisely estimate how good your position really is and quickly come up with sensible moves and plans.
If you are lacking in that department you tend to calculate a lot without achieving much. That results in time pressure and blunders just as surely as having calculation deficits.

So I would rather recommend a book like Positional Play by Jacob Aagaard. If you can easily solve the problems in this book, you can always go back to pure calculation.

By the way, there is a big difference between training calculation and training tactics. Solving tactics depends on seeing motives, training calculation depends on the ability to think far ahead without confusing yourself. So if you do go back to pure calculation, maybe you should try the Calculation book by Aagaard, or similar books by Dvoretsky.


No. In the general case, the ELO ratings of three people will not converge to some stable equilibrium, and here's why.
Suppose you have two players, A and B. B on average scores 66% vs A, so if they played enough games, B's ELO rating would converge to about 100 more than A's.
Now suppose we introduce player C, who scores 66% vs B on average, but never plays against player A.  If C and B play many games, their ELO difference will stabilize to about 100 as well.  If B kept playing games with A during this time, A would converge to about 100 less than B, with C about 100 more than B.
So, what happens when A finally starts playing C? For there to be stability in the ratings, we MUST have C score 76% vs A, because C is 200 ELO points higher than A.  If A scores better than that, A would gain points when playing C, causing the gap between A and B to decrease.  But then A would lose the points A gained if they started another long series with B.  In this case, the three ELO ratings are not only a function of how well they play against eachother, but also how often they play each opponent - clearly not an absolute rating in any sense.
So this begs the question, if B beats A 66% of the time, and C beats B 66% of the time, should we automatically assume that C beats A 76% of the time, as the ELO functions imply?  That doesn't sound too crazy, but for the 3 body ELO problem to be stable, this implied score would have to be accurate for ANY pair of ELO gaps between A-B and B-C.  There aren't any assumptions in the ELO model that this transitivity should work.


Openings have been classified roughly as being very "tactical and sharp" versus "positional and dull". For example: e4-e5 (king's pawn), e4-c5 (sicilian defense) fall under the former category, whereas d4-d5 (queen's pawn), e4-c6 (caro-kann defense) under the latter. But not all games strictly follow the above thumb rule, each opening can transpose to either tactical or positional depending on the lines chosen in the middle game.

That said, players chose their liking of openings and study various lines originating from the opening. Once the number of moves reaches 2 or above, the possibilities grow exponentially and hence most of the times will not result in the exact same game that the people had studied earlier, even at the grandmaster level, let alone amateurs.

You could open randomly, but in doing so you will be violating the basic opening principles and hence will most likely lose the game against an experienced player. You can check out the following link for some opening guidelines-

http://www.danheisman.com/opening-principles.html


How to search a chess database for exchange sacrifices?

Chess Query Language does do this very well. The following short .cql file works like a charm to find all games in input.pgn in which one side is up an exchange (while allowing a difference in the number of pawns for each side) for 4 straight moves (picked so as to rule out, say, situations in which an equal sequence of trades happens to begin with a rook taking a minor piece, or other such temporary pseudo-sacrifices).

(match
    :pgn input.pgn
    :output output.pgn
    (position
    :sequence(
        (position :powerdifference [Rr] -5 -5 :powerdifference [Qq] 0 0 :powerdifference [BbNn] 3 3)
        (position :powerdifference [Rr] -5 -5 :powerdifference [Qq] 0 0 :powerdifference [BbNn] 3 3)
        (position :powerdifference [Rr] -5 -5 :powerdifference [Qq] 0 0 :powerdifference [BbNn] 3 3)
        (position :powerdifference [Rr] -5 -5 :powerdifference [Qq] 0 0 :powerdifference [BbNn] 3 3)
    )
    :flipcolor
    )
)

Standard point values for pieces are used, so the :powerdifference [Rr] -5 -5 condition means that Black has one more rook than White, while :powerdifference [BbNn] 3 3 guarantees that White has exactly one more minor piece than Black. The :flipcolor at the end does the same search with the roles reversed. By default, CQL inserts a "MATCH" comment in the games of the resulting output.pgn at the positions that warrant their inclusion, so you can quickly locate the exchange sacs.


Of all the possible legal chess games, how many end in white win, draw and black win (assuming 50 move rule)?

The number of games is huge but finite, and estimates have been made based on a number of assumptions. But that question has been asked before already, so I won't go into the details here. A short answer given on Wikipedia is at least 10123, based on an average branching factor (moves per position) of 35 and an average game length of 80; after only 10 plies (5 full moves) the exact count is 69,352,859,712,417. See Is the number of possible chess games infinite? for more answers.

The probable outcomes of a game with random moves can be estimated "experimentally" by running random simulations. I wrote a program to do just that, had it play 1000 games, and these were my results:

Outcome                        Count  Avg. #moves
-----------------------------  -----  -----------
Draw by insufficient material    500          179
Draw by fifty-move               157          208
Draw by threefold repetition     147          164
Black wins by checkmate           75           87
White wins by checkmate           72           78
Draw by stalemate                 49          138

I think that the most common result is a draw because random moves are rather incompetent at mating, which requires the interaction of at least three pieces (counting both colors, including kings), in contrast with capturing, which is much easier to do by chance, only requiring the interaction between two pieces. After enough captures occur, you end up with insufficient material, which is the most likely outcome, occurring 50% of the time.

Alternatively, if you don't luck into a capture for long enough, you are also somewhat likely to bump into the fifty-move limit or threefold repetition. (My program assumes that these draws are claimed as soon as possible, even though they are not automatic per the rules, unlike 75-move or fivefold repetition.)

I don't expect a color advantage in random games. My sample had a few more wins with Black than with White, but I think that's within statistical noise.

For anyone who is interested, here's my program, written in Python and using the python-chess module:

import chess
import collections
import random

terminations = ['is_stalemate', 'is_insufficient_material', 'is_checkmate',
    'can_claim_fifty_moves', 'can_claim_threefold_repetition']

def get_termination(board):
    for termination in terminations:
        method = getattr(board, termination)
        if method():
            return termination

def game():
    board = chess.Board()
    for i in range(10000):
        moves = list(board.legal_moves)
        move = random.choice(moves)
        board.push(move)
        result = board.result(claim_draw=True)
        if result != '*':
            termination = get_termination(board)
            print(result, board.fullmove_number, termination)
            return result, termination

stats = collections.Counter()
for i in range(1000):
    result, termination = game()
    if termination == 'is_checkmate':
        stats[result] += 1
    else:
        stats[termination] += 1

print(stats)


Unfortunately the UCI protocol is stateless, there is no way to ask the engine to undo a move. The protocol is designed for communication between GUI and engine, you are supposed to have your own board representation such that you can update the engine.

For example, you would need to do:

position startpos moves e4c5
position startpos


I am looking for a software or web site, which allows me to place the pieces on the board, and then create FEN notation automatically.

I personally use this site for that.

It is free, and it is an online tool.

REMARKS:

If you wish to put that FEN in our diagram you paste that code like this:

Press space bar 4 times;
Type square brackets ( [] );
Type fen "" inside the brackets ( [fen ""] );
Paste your code inside the "" ( [fen "Your FEN goes here"] );

If you decide to input variations you need to do this:

Press enter twice;
Press space bar 4 times;
Input moves;

Here is an example:

If you have further question leave a comment and I will help you. Also read this thread.

END OF REMARKS

Hopefully this answer helps you.

Best regards.


How accurate is Chess Maniac's online rating estimator?

Absolutely inaccurate. ELO rating is determined by playing a whole game of chess, not by solving a few positions without any pressure.

Please play some online games for better estimate of your playing strength.


If I accidentally knock over a rook with my elbow while reaching for another piece, do I have to move the rook?

No.

The relevant part in FIDE's Laws of Chess is Article 4.3 which contains the word deliberately.

  4.3 Except as provided in Article 4.2, if the player having the move
      deliberately touches on the chessboard:

  a. one or more of his own pieces, he must move the first piece touched which can be moved

  b. one or more of his opponent’s pieces, he must capture the first piece touched which can be captured

  c. one piece of each colour, he must capture the opponent’s piece with his piece or, if this is illegal, move or capture the first
      piece touched which can be moved or captured. If it is unclear,
      whether the player’s own piece or his opponent’s was touched first,
      the player’s own piece shall be considered to have been touched
      before his opponent’s.

The situation you describe once happened to a team mate of mine. The opponent wanted him to move the touched piece according to the rule, but the arbiter explained it had to be deliberate.


Are connected doubled (4 pawns on 2 files) a weak structure?

It is a solid structure indeed, avoiding one of the most important weaknesses of doubled pawns, which is that they're generally hard to protect. Also, they're less easy to block than just a c- and d-pawn, since the backward pawns can attack enemy pieces on the blocking squares.

However, this structure only influences the b-, c-, d- and e-files, while a 'regular' connected pawn structure influences 6 files. Such a structure is also more likely to be able to force breakthroughs. Everything depends on context, as user1583209 notes, but in general it's better not to have doubled pawns.


Current top player with most aggressive style?

Baadur Jobava is probably the most aggressive top player right now. If you go even further up the ranking, Mamedyarov is very aggressive as well.

And although he is not one for wild and dubious attacks, Caruana is actually quite uncompromising, his draw rate is very low.

Topalov and Morozevich are two names that stand for aggressive chess. But I think they both slowed down in recent years. The same could be said for Nakamura.


Why is there a 50-move rule and a 75-move rule?

From the FIDE Laws of Chess:

50-move rule:

  9.3 The game is drawn, upon a correct claim by a player having the move, if:
  (...)
  the last 50 moves by each player have been completed without the movement of any pawn and without any capture.

75-move rule:

  9.6 If one or both of the following occur(s) then the game is drawn: (...) any series of at least 75 moves have been made by each player without the movement of any pawn and without any capture.

(emphasis mine)

As you can see, the decisive difference is that the 50-move rule only applies if a player correctly claims it, while the 75-move rule applies independently of any claims. So, in the 50 to 75 move window, the players can claim for a draw, but don't have to (and play on). Only when the 75th move without pawn moves or captures has been reached, the arbiter may interfere and declare the game drawn.


A nine pieces opposite color bishop endgame

This position is almost certainly a draw. Black's next move could be Ba8, blocking the a7 pawn and putting the bishop out of harm's way. So how would White proceed from there?
One possible White plan is to promote the a7 pawn. But the promotion square is light-colored, so it cannot be supported by the White bishop. To get support from the king, White needs to get their king to c7 and then b8. (b7 and c6 are guarded by the Black bishop, so the White king cannot use those squares.) But how? If they move the c7 bishop and then play Kb6, Black simply plays Kd7 (or possibly Kd6 or Kd8 if they need to waste a move, depending on the position of White's bishop.)
Another possible White plan is to take the g4 pawn. It's on a light square, so it cannot be taken by the bishop, so that means the king has to do it. But that doesn't work either. White's's king would need to get to f4 (perhaps via e3), but Black can easily move their own king to f5 (or e5 or g5) in time to prevent this.
I don't see any other possible plans. The Black bishop cannot be captured (we've established that the White king cannot get to b8 to threaten it) and the e4 pawn is protected by the Black bishop. Since the White king cannot penetrate into Black's position, the pawns are blocked, and the White bishop cannot make progress on its own, the game is drawn.
[FEN "8/P1B5/4k3/2Kb4/4p1p1/6P1/4P3/8 b - - 0 1"]

1... Ba8 2. Kb6 Kd7 3. Be5 Kd8 4. Bb2 Kd7 5. Kc5 Ke6 6. Kd4 Kf5 7. Ke3 Kg5 8. Kd4 Kf5 9. Kc5 Ke6 10. Kb6 Kd7


THE longest problem ever (much longer than the mere 549 mover...)

After some searching, it turns out that this monster is very much a real chess problem. The official name for it is  "The Obelisk."
The earliest known reference I have found is from February of 1882, mere weeks after its publication. Bizarrely, it comes from an Australian magazine. The site I found it on is trove.nla.gov.au.
It appears in 1882, February 25th edition of the South Australian Weekly Chronicle, published in Adelaide, on page 25. It is part of an overall review of Brentano's January 1882 issue.
Here is a clipping of the relevant section to read for yourself.

I also found mention of it in "American Chess Review, Volume 1, Issues 1-6" (readable on Google books) from 1886, just four years after the original publication in Brentano's Chess Monthly.
The information is given in the middle of the page. The position itself is given near the end of the page in descriptive notation (link to Wikipedia](https://en.wikipedia.org/wiki/Descriptive_notation)). Note that the "S" is German notation for the knight; it was semi-standard back then.

Here are later sources.

Chess Review 1936, issue 37 page 17; viewable online in the US Chess Federation online archive
Curious Chess Facts, by Irving Chernev, 1937
Wonders and Curiosities of Chess, page 205, by Irving Chernev, 1974
The Complete Chess Addict, by Mike Fox & Richard James, 1987
The Even More Complete Chess Addict, by Mike Fox & Richard James, 1994

Unsurpingsly, there is no solution given anywhere at all. The reason for this is that the magazine ceased publication soon after the mate in 1220 printed. Thus, another edition with the solution was never made.
As for how to interpret the stipulation, I believe it is very simple. Wite forces the Black knight to visit each and every square three times. Then White gives checkmates. Most of the moves come from White's piece dancing around in order to do said forcing. If anyone is crazy to try and solve it, they will surely find a much shorter solution than whatever Otto Blathy had in mind.


Gusev - Averbach is a good start; it reminds me of the following game, where less material is sacrificed (only a knight) but more pieces are dominated:

The immortal Zugzwang game

(taken from here)

[Date "1923"]
[White "Saemisch, Friedrich"]
[Black "Nimzowitsch, Aron"]
[Result "0-1"]

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1"]

1. d4 {Notes by Nimzowitsch's "My System"} Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7 6. Nc3 O-O 7. O-O d5 8. Ne5 c6 {Safeguards the position} 9. cxd5 cxd5 10. Bf4 a6 {Protects the oupost station c4, i.e., by ...a6 and ...b5.} 11. Rc1 b5 12. Qb3 Nc6 {The ghost! With noiseless steps he presses on towards c4.} 13. Nxc6 {Samisch sacrifices two tempi (exchange of the tempo-eating Knight on e5 for the Knight which is almost undeveloped) merely to be rid of the ghost.} Bxc6 14. h3 Qd7 15. Kh2 Nh5 {I could have supplied him with as yet a second ghost by ...Qb7 and ...Knight-d7-b6-c4, but I wished to turn my attention to the King's side.} 16. Bd2 f5 {!} 17. Qd1 b4 {!} 18. Nb1 Bb5 19. Rg1 Bd6 20. e4 fxe4 {! This sacrifice, which has a quite surprising affect, is based upon the following sober calculation: two Pawns and the 7th rank and an enemy Queen's wing which cannot be disentangled - all this for only one piece!} 21. Qxh5 Rxf2 22. Qg5 Raf8 23. Kh1 R8f5 24. Qe3 Bd3 25. Rce1 h6 {!! A brilliant move which announces the Zugzwang. White has not a move left. If, e.g., Kh2 or g4, then R5f3. Black can now make waiting moves with his King, and White must, willy-nilly, eventually throw himself upon the sword.} 0-1


No, 6. Qd4 is not a dubious move. In the variation that you mentioned, the moves that are actually dubious are 7...Ng8 and 8. e6

8. e6 is dubious because it "forces" Black to develop his knight to a good square (!) and also gives up White's strong central pawn on e5, which could have hindered the development of Black's knight on g8. After 9. exf7+, it may seem that Black is robbed of the castling option, but that is just superficial. Black can easily develop his bishop to g7 and bring the h8 rook to e8 or f8 as needed. None of White's pieces can really exploit Black's king position on f7, so White gains nothing from giving up the e-pawn.

7...Ng8 is dubious because there is a better square for the knight - d5. Also, after 7...Ng8, White isn't forced to play 8. e6, so the knight will have to waste another tempo for development.

6. Qd4 is playable. It has been played by players of the calibre of former world champion Emmanuel Lasker and also Grandmaster Beliavsky. After 6...Nf6 7. e5 Nd5, the position is equal but playable for both sides.

 [FEN ""]
 [White "6.Qd4"]
 [Black "Playable"]

 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Nxc6 bxc6 6. Qd4 Nf6 7. e5 Nd5 (
 7... Ng8?! 8. Nd2! (8. e6?! Nf6 9. exf7+ Kxf7) 8... Bg7 9. Nf3 d6 (9... f6 10. e6
 dxe6 11. Bc4 Qxd4 12. Nxd4 e5 13. Nxc6 Bb7 14. Bb5) 10. Bf4) 8. Nc3=


According to the Nalimov Endgame Tablebase: http://www.k4it.de/?topic=egtb&lang=en this position is a win in 40 moves for black, if black promotes for a knight to block the upcoming avalanche of checks.
However if black promotes for a queen it's a draw.


Has the King's Indian Defense been refuted at the Grandmaster level?

Short answer - no.

Plenty of strong grandmasters like Radjabov and Caruana still play it.

Latest games


Caro-Kann variation 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5

EDIT ( December, 30 2013 ):

Removed unnecessary book from the list
Added explanation of basic ideas in response to the comment made by member Jonathan Garber

  I would like to play the Modern Variation of the Caro-Kann. What is the best way to deal with Ng5? Best strategy and known tactics (e.g. the Ne6 sacrifice).

You did not specify which side you wish to play, but I have assumed it is Black side you are interested in, judging by the sentence "What is the best way to deal with Ng5?".

The only dangers that I see are the move Bc4 and Bd3 coupled with Ng5, since there is always the possibility of the sacrifice on e6.

When playing Bc4, White hopes for something like this:

[FEN ""]
1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ngf6 6.Bc4 e6 7.Qe2 h6? 8.Nxf7!

This is the place where you play 7. ...Nb6 and White can reply with 8.Bd3 or 8.Bb3.

After 8.Bb3 you play 8. ...h6 and then strike with 9. ...c5. The remaining variations are not that theoretical, and you need to remember some key moves to secure equal chances.

The trap in the above diagram was the only critical position requiring from you to play precise and theoretical move.

The Bd3 continuation is different. Here White has more opportunities for positional sacrifices, since he gets the compensation in view of space advantage, pressure on the Black king stuck in the center and the lead in the development.
This is the place where you must know theory and always take care in first 10 or 13 moves.

[FEN ""]
1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ngf6 6.Bd3

If you play 6. ...h6?! here White can respond with 7.Ne6! and will just calmly develop, sacrificing the knight since he gets very good compensation in view of the initiative, development lead and Black's cramped, uncoordinated position.

Another dangerous variation with White's same idea is this:

[FEN ""]
1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ngf6 6.Bd3 e6 7. N1f3 h6?! 8.Nxe6!

Instead of 7. ...h6?!, Black plays 7. ...Bd6 and from here on, you really must know theory, as I have mentioned before, since things get really messy. Note that it is harder to play this variation with Black, than with White, but the resulting position is unclear and sharp, so you both have equal chances.

  Maybe you can recommend a book dedicated to this variation?

As someone who used to played this defense as Black in tournament games, I can recommend you some books that helped me to learn to play this opening variation with good success:

Joe Gallagher-Starting Out The Caro-Kann
Anatoly Karpov and A.Beliavsky-The Caro-Kann in Black and White
Shandorff Lars-Grandmaster Repertoire 7-The Caro-Kann

Start reading them in order I have presented above.

The first one will help you to grasp basic ideas and concepts of the variation you seek, but will also help you with other variations as well-which is important since generally in Caro-Kann it is White who can steer the game, not Black. You will find the answers you seek in this book. I have just given you the small summary of ideas in the above section.

Once you learn the basics you can move on to the second book, written by a grandmaster who practically reinvented the whole variation for Black. It is Karpov who first used that variation in the candidate matches. That is why he had to do everything almost from scratch, and that is why I believe that this book will be the most useful to you. You will learn from one of the best players in chess history and who can better explain to you the ideas for Black than the one who invented them? This book will show you the annotated games where White or Black played well, and their opponent bad. It is important for you to know what is good for White and what is good for Black in the variation you wish to master.

After you learn the opening moves, and grasp the middle game that arises from it, you will start to improve rapidly, since the opening is very solid and hard to "crack" on the lower levels of skill. Naturally you will want to play for a win. In order to do so, you will need the sharpest and most precise continuations and that is what third book should help you with.

A SMALL ADVICE:

Get a good book on endgames, you will need it.

Hopefully this will help you.

Best regards.


Options for following the Norway Chess tournament live

You can follow the event live from various platforms, to name a few:

Chess24: live broadcast of moves and engine analysis available to all
users, and the live commentary provided by Jan Gustafsson and Peter
Svidler restricted to premium members for this event.
But all broadcasts are recorded and available freely on their youtube
channel, including Peter Svidler's analysis of a game of the round.

Chess24's page for current round
Related uploaded videos on their youtube channel

Lichess: also provides the live broadcast of moves via its dedicated
study page for each round of the tournament. The advantage is more
freedom to customize the engine analysis while following a game and also more suitable for following the moves live from your phone.

Dedicated study page for current round

Miscellaneous: There are also various streams providing commentary for the event (see e.g. the twitch page of chess streams), among them is the chessbrah channel having Yasser Seirawan and Nils Grandelius currently as guests.

Twitch page of live chess streams
Chessbrah channel, with invited guests providing live commentary.

So there's plenty to choose from given what you're most interested in.
If there's one thing I would definitely recommend, is to watch Peter
Svidler's post analysis videos of the game of the round
as they are highly instructive and fun.

All of his uploaded sessions on chess24's YT
Restricted to the Norway Chess event


According to 365chess.com, Aivi Karu was a female player from Estonia.

She has 12 games logged, including those with Keres, and scored 20.83%. In fairness, she played against highly rated players (elo's above 2000), so my guess is that she was an amateur player who played some correspondence, training games and open tournaments where she was inevitably mismatched.


What is the most effective way to beat the computer at chess?

Computers have a few advantages over us: speed, memory, and they don't make mistakes (based off the code they're written on). This allows them to go very far ahead in the search tree, navigating the tree perfectly. However, with an engine you estimate to be around 2200, you may have advantages in position evaluation and intuition.

With this in mind, there are a few things you can do:

1) Aim for positions where a high search speed isn't as important. Closed positions are ideal, as you mentioned.

2) Try to drive the game towards positions that you feel comfortable evaluating. An engine rated only 2200 may have an advantage in a concrete tactical position, despite its vastly reduced search depth compared to an engine like Stockfish. But in a positional structure you have experience with, you may have the advantage.

3) Don't go too far out of your way to play differently though. If you get carried away with this, you'll only be playing the opponent and not the game. One reason Kasparov ran into trouble against Deep Blue was that he figured a computer wouldn't make a calculation mistake. If you yourself are around 2000-2200, you already have a decent chance of scoring against a 2200 player.


How to develop tactical and combinational awareness?

The recommended way to improve tactics is to practice looking for them.  ChessTempo is the best site to practice tactics.  chess24 also has tactics training and has good videos.  Lichess has tactics and one of the best playing sites.  Youtube.com has too many chess videos to list them all.
There are some clues to look for to find tactics.  An unprotected back rank, pieces which are on the same line, pieces which are a Knight fork away, and pieces which are unprotected.  More advanced themes are overloaded piece, trapped pieces, and zwischenzug et al.
Alburt's 300 most important positions and Reinfeld's 1001 best checkmates are PGNs which you can download.  Chess Hero is a program which will test you with these files (includes Reinfeld's pgn.)
Along with tactics, you will find attacking becomes easier.
spy-faith(2113) jonesmh(2052) lichess.org 3 0
Exploiting an overloaded Knight on c3.

   [FEN ""]
1. e4 c5 2. d4 cxd4 3. c3 d3 4. c4 g6 5. Nc3 Bg7 6. Qxd3 Nc6 7. Bf4 d6 8. O-O-O Nf6 9. Bg3 O-O 10. f4 Qa5 11. Kb1 Nb4 12. Qd2 Nxe4 0-1

jonesmh(2000) mitchell(2000)
Unusual attack on the king.

[fen "r3rbk1/ppq2pp1/2n2n1p/2pp1P2/5P2/2PBB2P/PPQN2P1/R3R1K1 b - - 0 0"]

1...c4 2.Bf1 Rxe3 3. Rxe3 Bc5

With every piece protected, the attack broke through.  A hard example of a weak square complex.
jonesmh(2080) kavookavala(2133) lichess.org 3 2
Exploiting uncoordinated pieces

[fen ""]
1. f4 d5 2. e4 dxe4 3. Nc3 Bf5 4. Qe2 Nf6 5. Qb5+ Bd7 6. Qxb7 Bc6 7. Bb5 Bxb5 8. Nxb5 Qd5 9. Qc8+ 1-0

jonesmh(2079) nfc3000(2061) lichess.org 3 2
Overlooked Knight fork by both player.

[fen ""]
1. e4 c5 2. Nf3 d6 3. d3 Nf6 4. g3 g6 5. Bg2 Bg7 6. O-O O-O 7. Nbd2 Nc6 8. a4 Bd7 9. Re1 a6 10. Nc4 Rb8 11. a5 Be6 12. e5 Bxc4 13. exf6 Bxf6 14. dxc4 Nxa5 15. Qd3 Qc7 16. Bd2 Nc6 17. c3 Ra8 18. Bh6 Rfb8 19. Qe2 Na5 20. Bg5 Bxg5 21. Nxg5 Re8 22. Rad1 Rab8 23. Qd3 b5 24. cxb5 axb5 25. b4 Nc4 26. Bd5 Ne5 27. Rxe5 dxe5 28. Bxf7+ Kg7 29. Bxe8 Rxe8 30. Ne6+ 1-0

These examples show that 2000 rated players miss simple tactics in blitz.  The longer you play and/or solve tactical puzzles, the easier you will find the combinations..
(As I kept going back and forth to input the examples, I lost track of what I was saying many times.  Hopefully I did not stray off topic too much and did provide helpful information.)


The board layout can be repeated at most 11 times with White having the move, the 12th will be a draw.
[FEN "rnbqkbnr/1pp2pp1/4p3/p2pP2p/P6P/8/1PPP1PP1/RNBQKBNR w KQkq d6 0 1"]

1. Be2 {White can no longer capture en passant.} Be7 2. Bf1 Bf8 {2nd time} 3. Be2 Be7 4. Bf1 Bf8 {3rd time}
5. Rh2 {White can no longer 0-0} Be7 6. Rh1 Bf8 {4th time} 7. Rh2 Be7 8. Rh1 Bf8 {5th time}
9. Ra2 {White can no longer 0-0-0} Be7 10. Ra1 Bf8 {6th time} 11. Ra2 Be7 12. Ra1 Bf8 {7th time}
13. Be2 Rh7 {Black can no longer 0-0} 14. Bf1 Rh8 {8th time} 15. Be2 Rh7 16. Bf1 Rh8 {9th time}
17. Be2 Ra7 {Black can no longer 0-0-0} 18. Bf1 Ra8 {10th time} 19. Be2 Ra7 20. Bf1 Ra8 {11th time}

However (emphasis mine):

9.2.2  Positions are considered the same if and only if the same player has the move, pieces of the same kind and colour occupy the same squares and the possible moves of all the pieces of both players are the same.

So:
[FEN "rnbqkbnr/1pp2pp1/4p3/p2pP2p/P6P/8/1PPP1PP1/RNBQKBNR w KQkq d6 0 1"]

1. Bd3 Bc5 2. Be2 Bf8 3. Bf1

is not a repetition of the original position (it's Black's turn now), although it is the same board layout.
Therefore: the position can be repeated 10 times (excluding the initial position), multiply this by 2 (2 more times the layout can be repeated with Black's turn) and add 1 (the initial position) + the final repetition on which the draw is claimed = 22 times.


How to minimise your opponent's fun in a game?

I play for two purposes:

  to win the game, or when winning is unlikely, to draw the game.
  to improve my chess skills, which eventually enables me to win/draw more games.

These are good goals, although you might want to add "to have fun" because if you don't have fun you are quickly going to lose motivation.

  I do not care about my opponents' fun.

Also good, because if you care too much about your opponents' fun you will end up losing focus and not follow your two stated primary goals.

  Is the idea of destroying your opponent's fun good?

No, it is counterproductive. If you start focusing on how much fun your opponent may or may not be having then this can only distract you and detract from your game. If, for the purposes of this question you are going to be truly self-centered then you cannot let your opponents' feelings, good or bad, enter into your considerations. It can only lead to bad play on your behalf. Concentrate on making the best moves.


What are some beginner opening variations after an opening has been chosen?

I would say that it almost does not matter. I think that anyone under 1700 USCF will get far more out of the study of the basics of the opening phase of the game and the general strategic ideas of the specific opening she or he has chosen. From a practical perspective it is too difficult to say what you are going to get 13 moves into an under 1600 USCF game to really dedicate too much time to an opening.

So the exact variation simply does not matter at the beginner level (assuming that is players under 1400 USCF). Notice in my terminology I consider a novice to be someone completely new to chess who has never played in a tournament and really only knows how the pieces move and the basic rules. I distinguish this from a beginner who knows a bit more about chess, may have played in a tournament, has a rating under 1400 USCF as mentioned before. I know these terms are generally synonymous but I think that it's important to distinguish between these two types of "beginners".

So my suggestion would be that at the beginner level one just shouldn't be too concerned about picking the exact variation but instead dedicate more time to learning about the general ideas of more openings by studying GM games from a variety of openings in addition to the openings you have chosen to play and keep your memorized book to a minimum.

Here are some suggestions on how to study the opening from Dan Heisman:
http://www.chesscafe.com/text/heisman37.pdf

  When a player first starts out to learn the openings, he gets the most
  efficient use of his time by learning:

  General opening goals and guidelines,
  A few main opening sequences (tabiyas), and
  How to avoid making the same mistakes over and over.


To my knowledge there is no such iOS app. Sorry.

Try the Chessbase Fritz to do the conversion.


Dynamic (not-drawish) response for black against the c3 Sicilian

The line with Nf6 is actually pretty interesting. I think you overlooked the main line which is 6...c4, not 6...g6. For the record, the delayed d4 is the less popular variation. It leads to unbalanced play:

[fen ""]
1. e4 c5 2. c3 Nf6 3. e5 Nd5 4. Bc4 Nb6 5. Bb3 Nc6 6. Nf3 c4 7. Bc2 Qc7 8. Qe2 g5 9. e6 dxe6 10. Nxg5 Qe5 11. d4 cxd3 12. Bxd3 Qxe2+ 13. Bxe2 h6 14. Ne4 e5

There are of course other sidelines in this variation, with a major alternative being 9. h3 for white, but I encourage you to look into it some more.


Does chess help develop moral virtues or correct practical attitudes?

Chess definitely helps with intellectual development and education. Math is the most obvious area where chess definitely helps. There is a lot of research to back this up. If you think about it, chess develops general mental abilities including: strategic competency; the ability to analyze variations; spatial relationships and interdependencies; self-confidence in the face of complex problems. All of those abilities are generally useful in solving all kinds of problems in school and life.

Here are links to some web resources where you can read more about the well-documented benefits of chess in education.

http://education.jhu.edu/PD/newhorizons/strategies/topics/thinking-skills/chess/

http://www.psmcd.net/otherfiles/BenefitsOfChessInEdScreen2.pdf

These are just two examples. There are a lot more articles out there on the Internet, and they mostly arrive at the same basic conclusion.

Moral virtues are another story.

Chess doesn't directly help with moral values. Bobby Fischer was a great example of this. He was a brilliant chess player, but widely regarded as the worst kind of person. He had very clever and elaborate arguments to support his negative and self-destructive points of view. There are many examples of top level chess players who are wonderful people, but also quite a few examples of immoral behavior among grandmasters.


Thanks to Henry for the tip. Here is my solution.

var kingOnRightField = function (groundRow, king) {
    var index = 0;

    for (var i = 0; i < groundRow.length; i++) {
        var number = parseInt(groundRow[i]);
        index += isNaN(number) ? 1 : number;

        if (index == 5 && groundRow[i] == king) return true;
    }

    return false;
};

var fen = "r3k2r/3q4/8/8/8/8/8/R1Q1K1RR";

var blackGroundRow = fen.split("/")[0];
var whiteGroundRow = fen.split("/")[7];

var blackKingOnRightField = kingOnRightField(blackGroundRow, 'k');
var whiteKingOnRightField = kingOnRightField(whiteGroundRow, 'K');


Are there studies showing that descriptive notation is easier to use for blindfold than algebraic notation?

If there are studies, they'd show descriptive to be the lesser of the two because in descriptive, all the squares have two names; in algebraic, just one. So if you're having to keep a game in your head, it's easier to do so with 64 identifiers to remember than 128, right?
If you practice playing blindfolded, you'll find that your only use for notation is transmitting the moves back and forth.


2.f3 looks like a terrible move. It wastes a tempo by not developing a piece; it takes f3 square away from the knight, and it weakens a7-g1 diagonal, while achieving absolutely nothing. I think that after any normal move (2...d5, 2...Nc6, 2...Nf6, 2...Bc5) black has the edge.

While I don't see any reason to give up the advantage so early, I don't think white is lost (just slightly worse), so white can play it if they want to.

I also think that 1. e4 e5 2. Nf3 f6 leads to a "disaster" is an overstatement. 1. e4 e5 2. Nf3 f6 3.Nxe5 fxe5?? does lead to a disaster; however, black can play 3...Qe7.


Which was that Marshall's game with that spectacular Queen sac?

I believe it was Levitsky vs Marshall

[FEN ""]
1. d4 e6 2. e4 d5 3. Nc3 c5 4. Nf3 Nc6 5. exd5 exd5 6. Be2 Nf6 7. O-O Be7 8. Bg5 O-O 9. dxc5 Be6 10. Nd4 Bxc5 11. Nxe6 fxe6 12. Bg4 Qd6 13. Bh3 Rae8 14. Qd2 Bb4 15. Bxf6 Rxf6 16. Rad1 Qc5 17. Qe2 Bxc3 18. bxc3 Qxc3 19. Rxd5 Nd4 20. Qh5 Ref8 21. Re5 Rh6 22. Qg5 Rxh3 23. Rc5 Qg3   (23... Qg3 24.Qxg3 Ne2+ 25.Kh1 Nxg3+ 26.Kg1 Nxf1 27.gxh3 Nd2)


The pin of the e6 pawn doesn't seem important at all in this position.  In fact, it is hard to see what White is trying to accomplish with Bc4.

By "going into Stonewall" I guess you mean .. d5, and that is certainly tempting, seeing as White will have to lose a tempo just to put his Bishop on another not-great square.  For an alternative, consider .. Nc6, getting ready for b6 and Bb7 deploying your light-square Bishop beautifully with action on the central squares d5 and e4.  Also, after .. Nc6 the d5 idea will never work for White due to .. Nxd5! and White's g5 Bishop is hanging.


Where did this Emanuel Lasker quote come from?

The correct wording is "properly taught, a student can learn more in a few hours than he would find out in ten years of untutored trial and error". The oldest reference to the quote I found is in this newspaper article of 1973.


Where to buy my favorite magnetic chess set

Is this what you're after?

Chess set

Vintage plastic magnetic chess set in carton box.
Made in USSR, Latvia.
Material: Plastic, magnet.
Circa: 1980s.
Has vintage condition. One white figurine has a crack, black king missing the top.
Measurement: the box is 250 x 130 mm (9 7/8" x 5 1/8")

One problem is the black king in this set is also missing the white top, in which case you would have one incomplete piece. Also, the board has a black edge instead of white, however hopefully that isn't a problem.


Where I can download images of chess pieces for my chess app?

Check out the licenses of the piece sets that lichess uses: https://github.com/ornicar/lila/blob/master/COPYING.md#exceptions-free
Personally I am using the cburnett piece set for my project.


What is the worst possible first move for White: 1.f3 or 1.g4?

f3 doesn't contribute to the piece development ( it actually hinders it by taking away the best square for the Ng1 ), it doesn't fight for the center ( it only strengthens the e4 square that White can claim anyway with 1.Nc3 or 1.e4 ) and above all it exposes the king.

g4 vacates g2 for the Bf1 ( fianchettoed bishop is usually good ), it helps in the fight for the center indirectly ( you can weaken Black's control of d5 and e4 if Black plays ...Nf6 at some point, by simply playing g5 ) and pawn at g4 can be useful in kingside attack if Black castles short. It does weaken f4 and h4, so it is somewhat dubious, but it is playable ( although I doubt White can reach full equality...).

Therefore, when we compare the above facts, we can see that 1.f3 is clearly the worst first move, based on the opening theory ( since only one move is played it is to early to make final conclusions, since White may transpose into decent position with his next moves ).


In Caro-Kann, which one is less risky, the main line or the Steinitz?

Regarding your question, as far as I remember, both lines hold.

Bf5 gave White a lot of options to fight for an advantage. It got revamped with the help of the computers, Black seeking to generate more active counter-play by castling short instead of long, but I had no courage to try those positions out as they were too wild for my taste.
Nd7 was regarded as more solid, giving White less attacking options, but also requires more enterprising play from Black.

Sadly, user q.undertow is right. There is no safe line in the Caro-Kann.

Allow me to explain why:

Since it's creation, it was considered inferior to French defense, masters arguing that 1...c6 is too slow, Black not fighting energetically enough for the center. This fact gives White enough time to put pressure on Black. This will always be the case with Caro, Black argues that he will be able to withstand the pressure and cash in White's over-extension in the endgame.

In some lines, White plays outrageous moves, almost "all-in"-ing, forcing Black to invest reasonable risk, in order not to lose. These positions are ugly for the eye of the beholder, but that does not matter. What matters is that objectively, the positions are sound and not inferior for Black.

Before the endgame, comes middlegame. Relinquishing initiative to White, Black will have to defend some serious threats and nobody in the old days knew just how far can White go with his aggression. They tried to play positionally, relying on general principles, but this approach gave only a small plus for White, so he turned to "all-in"-ing, backed by computer analysis. These new moves broke every principle they could, but still remained viable, forcing Black to reply in equal manner in order not to get crushed, generating mind-boggling positions.

Sadly, it is White who steers the game, so if he wants to, he can drag you into sharp positions. Positional lines hold for Black (last time I checked) so you should have no problems there as their plans are not difficult to grasp.

If you do get dragged in the complications, book yourself up, you won't be able to save yourself with calculation and general principles. From my experience, it was harder to play as Black, more stress, easier to make a mistake, less options to generate counter-play...


A piece was knocked down during a blitz game

When you placed an upside down rook on the board instead of a queen you made an illegal move. In blitz the first illegal move losses the game. You lost. What happened afterwards is irrelevant.

There are differences between blitz and standard chess (longer time control). In standard chess you are allowed one illegal move but the punishment is your opponent gets an extra 2 minutes on the clock. The second illegal move loses.

Actually the position in blitz is more complicated than I said above. If an arbiter sees your illegal move he will stop the game and forfeit you. If the arbiter doesn't see then it depends what your opponent does. If he claims the game then you lost. If he plays on then he accepts the illegal move and the game continues.

The problem is that your upside down rook is not a queen, it is an upside down rook. Every time you move it like a bishop (which the queen is allowed to do) you make an illegal move. If an arbiter sees you move an upside down rook like a bishop he will forfeit you the game. Your opponent can also claim the game for an illegal move every time you do this.

Your opponent cannot claim the game because you knocked pieces over. If you correct the position on your own time that is OK. If you already pressed the clock your opponent would be entitled to start your clock while you pick up and replace the pieces. If you continually do this the arbiter can give you a time penalty by giving your opponent an extra minute on the clock and then if you do it again after that he may forfeit you.


How to know how good an opening/defense scores?

if you decided to know how good an opening/defense scores, is there an online database that keeps track of all the games ever played, or do you take for granted what other players told you?

For instance if you buy Chessbase, it will deliver a big database with some games. There you can look up for the openings, which were played by the big players. I like to hear and take tips from my trainer, rather than believing in some game from two players with > 2400 Elo. They play completely different, than most of the players. You don't really understand their plans and moves, unless someone comments the game and explains everything. They are not fighting for pieces / pawns, they just fight for one square, which is weak and then in the end-game they will win it eventually, because of this one little weak square.

  How to know if the Najdorf for example is a good opening, maybe Fischer and kasparov won, because they are good players, not because the opening is good. Same question about bad opening and defenses, I mean in the middle game if the player is bad, no opening will let him win.

Fair enough question. If the opening isn't good, wouldn't someone else beat them there (some other good players or an engine)?

The last point is also true. I had many games, where I dominated in the opening but lost it in the middle / end game.

  Don't good openings become bad opening when they become well known? I mean lets use the Najdorf again as an example, because everyone wants to learn it, it is so well known, doesn't that make it a bad opening? The opponent will be well prepared for it.

That's partly true. If your opponent is prepared, you have to be prepared too, but this doesn't mean that it is a bad opening. Especially in Najdorf there are so many variations, you have to know them, when you want to play it.

  And lastly, is it better to play openings/defenses that score good (french defense. indian etc..) or is it better to play an opening that is not well known and that your opponent didn't learn?

This depends on how / what you want to play. I like to play some aggressive stuff. I used to play French defense, but it wasn't my opening. I was losing nearly every game, then I changed to Sicilian and now I win about 25%, draw about 50% and lose about 25%.

If you play something that's unknown, your opponent could still beat you in the opening, because he knows how to play chess (maybe he is also better) and will just spend some time during the opening and analyzing it.


Why is it necessary for black to defend e5 pawn after 1. e4 e5 2. Nf3?

It's not necessary; the solid Petrov's Defence continues with the counterattack 2... Nf6. There's also a less stable option in 2... f5, the Latvian Gambit but it rarely sees play at the top level.

Otherwise, the real problem for Black is not the knight on e5. It's the fact that you're giving away a center pawn without any compensation whatsoever. If you want to develop pieces, you're even better off playing 2... Bc5 than 2... a6.


Is it acceptable to pair a player with the same colour three times in a row?

Lodging an appeal also came to mind that time. However, can the result
  actually be changed?

No. Only in extreme cases such as cheating can the result be changed.

  Or should the game be replayed?

No. There is no reason why the game should be replayed.

  In addition, as I am not an arbiter, is there an option in Swiss
  Manager (the pairing program which was used to make the pairings) not
  to allow players get the same color 3 times continuously?

Swiss Manager uses the JaVaFo pairing engine written by FIDE. The pairing engine implements the FIDE defined pairing rules. As far as I know (I am a FIDE arbiter) the only pairing rule that can be overridden is the one which says that a player who has already had a voluntary bye can also be given a compulsory bye in a later round given an odd number of players. In my experience this is never done.

  In the last round, I played with Black and my opponent with White.

  After the game, which I unfortunately lost, due to the lack of opening
  preparation, I realized that my opponent had taken White 3 times in
  the 3 last rounds. Playing with opposite colours was also impossible,
  since I had White 2 times continuously. In addition, I had played with
  most of the players which were up to the 10th position, so I couldn't
  find anyone else to play - maybe this is an exception?

In the FIDE Handbook the rules for Swiss pairing are given in the section Basic rules for Swiss Systems.

Your case is covered by these two rules.

  f For each player the difference between the number of black and the
  number of white games shall not be greater than 2 or less than –2.
  Each system may have exceptions to this rule in the last round of a tournament.

  g No player shall receive the same colour three times in a row.
  Each system may have exceptions to this rule in the last round of a tournament.

In the last round of a tournament the requirement to allow the highest placed players to play each other in the interests of having clear winners and major places decided fairly takes precedence over most of the other rules. The rule which says that two players who have already played in an earlier round cannot be paired against each other again takes precedence over all other rules and cannot be broken.


How is the life of a professional GM with ELO around 2500?

I know a few GMs in 2500-2600 range who would be considered professional -> ie chess provides the primary means of earning income for them.

It is very hard work with wages not matching the effort/skill spent:

Being the primary player for medium club team (European/Middle East/Far East)
Teaching (preferably within said club as it guarantees steady supply of clients)
Being an personal assistant/coach to another player
Playing for hire for a stronger club in say Bundesliga lower boards
Actually getting some prize money in medium sized tournaments
Books provide a tiny bit of income, but mostly are used for name/brand building for the next item
Selling training coarses - again only a few can make a living from this
A growing but still insufficient means of income is streaming, a few personalities can pull it off
Playing in special norm tournaments, in Eastern Europe GMs get about 250-350Euros for a week long tournament, where IMs/FMs/untitled have to pay 100-300 Euros to compete for GM norms.

That said most GMs around 2500 have other means of living besides chess.


Am I allowed to call the arbiter on my opponent's turn?

You are absolutely allowed to call the arbiter when it is your opponent's turn. There are any number of reasons why this would be necessary.

To start with the most prosaic, you have filled your scoresheet and
need another one.
You are feeling unwell and need medical assistance
Your opponent has picked up a piece but isn't sure where to move it to. They are holding the piece above the board, obscuring your view of the board and distracting you.


This question led me to spend two hours of my life looking at a line that I most likely never will get to play.  I went into it being quite confident that Nd5 was a bad move simply because White would get too much development for the cost of a simple pawn.  Analysing back and forth with Houdini has nevertheless convinced me that Nd5 is perfectly playable.

The similarities to the Sokolsky Opening

To get a feel for the b4 pawn it helps to understand a variation from the Sokolsky Opening.  It goes like this:

[FEN ""]

1. b4 e6  2. Bb2 Nf6  3.b5

Here the pawn on b5 is slightly annoying.  It cannot be easily removed as a6 can be answered by a4 (it does not matter if the rooks are swapped off as White intends to castle short anyway) and c6 can be answered by e3 when Black must take away from the centre to remove the pawn.

In the game, however, Black can simply play a6 in the similar position as White can't answer with a4:

[FEN ""]

1.f4 Nf6  2. b4 e6  3.b5 a6

So after 2...e6 White is only left with 3 a3, which, although reasonable, is another pawn move on the wing.  Black will be very solid after playing simple development like d5, Bd6 and 0-0.  This is slightly better than one of the main lines of the Sokolsky Opening, which is not that good to start with (but where White often ends up playing f4 later).

Houdini 3 on 2...Nd5

The currently strongest engine on the planet is Houdini 3.  When you let it analyse the position before 2...Nd5 to a depth of 25 it likes 2...d6 (claiming a small advantage for Black) the best (with 2...d5 as a strong second).  2...Nd5 does not come up as a top five alternative.  Houdini is initially not impressed by grabbing the pawn.

White plays 3 e4

Nevertheless, 2...Nd5 is still an interesting alternative and certainly gives more entertaining variations to look at.  First let us take a look at what happens if White plays 3 e4 after 2...Nd5 and then Black takes the pawn at b4:

[FEN ""]

1.f4 Nf6  2.b4 Nd5  3.e4 Nxb4  4.c3 N4c6  5.d4 d5  6.Nd2 dxe4  7.Nxe4

To explain this variation it is important to know that Black's hope and main idea against a setup with f4-e4-d4 is to play d5 and develop Bc8 to f5or g4.  In the variation above it turns out Black can't play either.  Bg4 simply hangs the bishop and Bf5 runs into Ng3 chasing it back.  Here I (and Houdini) believe White has compensation for the pawn (although perhaps nothing more).

So, let us look at the alternative.  Initially I was sure that 3...Nxf4 must be horrible for Black, but it turns out it is good after 4. d4 e5!:

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.e4 Nxf4 4.d4 e5 5.dxe5 Ne6

As seen above, if White makes the natural capture on e5, Black just retreats the knight.  Material is now even, but Black has two threats; The killing Qh4+ and just grabbing the b4 pawn.  So Black will end up a pawn up with a much better pawn structure and no imminent attack from White.

Instead White must play:

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.e4 Nxf4 4.d4 e5 5.Nf3 Ne6 6.d5 Nd4 7.c3 (7.Ng5) Nxf3+ 8.Qxf3 a5

In the above variation please note that 6 Nxe5 runs into 6...Qxh4+.  The same idea works against 7 Nxd4.  And despite all the knight moves Black is left clearly better in this variation too.  If you want to play this variation with White you need to try the chaotic 7.Ng5!?, hoping to trap the knight at d4.  Have fun analysing that.

White plays 3 d4

I believe 3 d4 is a strong alternative for White.  If Black takes the pawn on b4 it transposes to a variation we have already looked at:

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.d4 Nxb4 4.c3 N4c6 5.e4 d5 6.Nd2 dxe4 7.Nxe4

So, as I mentioned in a comment to the question, perhaps Black can try the amazing 3...Nf6 with the simple plan of d5 and Bf5.  In this variation White will have more space, but also more weaknesses (and, no, Black is not behind in development):

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.d4 Nf6

White plays 3 Bb2

Seeing that White will lose one pawn anyway, why not play a development move like  and see which pawn Black decides to take?  It seems that Black can just grab the f4 pawn and get away with it.  Let us see what happens if White tries to push Black off the board:

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.Bb2 Nxf4 4.e3 Ng6 5.h4 h5 6.Be2 d5 7.Bxh5 Qd6

White won the h5 pawn, but now the threat of Qg3+ is just killing White.  Instead, if White tried some quiet development moves:

[FEN ""]

1.f4 Nf6 2.b4 Nd5 3.Bb2 Nxf4 4.e3 Ng6 5.Nf3 e5 6.Nxe5 Nxe5 7.Bxe5 Nc6

Black gets a small advantage by the precise 5...e5 which trades the not so optimally placed Ng6 (Black is still a pawn up).  Note that the alternative 3 Nf3 could easily transpose as it does not seem that White can improve much

Conclusion

The fork 2...Nd5 works out well for Black, despite Houdini's initial reluctance towards it.  It seems White should play 3 d4 to equalise.  I would certainly try 2...Nd5 should 1 f4 Nf6  2 b4 be played against me.


There is no general rule in naming openings or opening lines in general or gambits. Sometimes it’s the inventor, sometimes the place they lived, they were born, they played the line the first time, and so on. To make it more complicated, openings can have different names in different languages. In German, the Petroff defence is named Russian defence, and Benko Gambit is called Wolga-Gambit. The Sokolski is also called Orang-Utan. So there really is no general rule but in some cases some amusing histories.


Which openings lead to unbalanced endgames?

First note that it is impossible to force your opponent into an endgame - chess doesn't work like that. Second, strategically the endgame may be one of the better choices for the opponent eg in the Berlin Defence the consensus on White best option is between the Berlin endgame and the Anti Berlin 4.d3, or equally it may not be, which doesn't mean you can't play it anyway if you like endgames. For examples of opening ideas that lead to unbalanced endgames see the games of Kramnik for example

Kramnik-Timman Wijk aan Zee 1999.

  [StartPly "7"]
  [FEN ""]
  [Event "Wijk aan Zee"]
  [White "Vladimir Kramnik"]
  [Black "Jan Timman"]

1.Nf3 c5 2.c4 Nf6 3. Nc3 Nc6 4.g3 d5 5.d4 cxd4 6.Nxd4 dxc4 7.Nxc6  Qxd1+ 8.Nxd1 bxc6

Kramnik-Van Wely Wijk aan Zee 2001

  [StartPly "7"]
  [FEN ""]
  [Event "Wijk aan Zee"]
  [White "Vladimir Kramnik"]
  [Black "Loek Van Wely"]

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.cxd5 Nxd5 6.e4 Nxc3
7.bxc3 c5 8.Be3 Qa5 9.Qd2 Nc6 10.Rc1 cxd4 11.cxd4 Qxd2+
12.Kxd2

Kramnik-Tomashevsky Tal Memorial 2012

  [StartPly "7"]
  [FEN ""]
  [Event "Tal Memorial"]
  [White "Vladimir Kramnik"]
  [Black "Evgeny Tomashevsky"]

1.Nf3 d5 2. d4 Nf6 3. c4 c6 4. Nc3 a6 5. e3 e6 6. Bd3 dxc4 7. Bxc4 c5 8. O-O b5 9. Be2 Bb7 10. dxc5 Qxd1 11. Rxd1

All of which won by White. These games are main lines - at least the last two are. I'm not too sure about the English opening in the first game.


Compile StockFish optimized for arm64-v8a

https://forum.armbian.com/topic/9862-info-how-to-compile-the-actual-64bit-version-of-stockfish-chess-engine/

Seems to show that you have to hack it to get it to compile at all.


White's best move seems to be 6. N1c3, when 6... d6 transposes into the Sveshnikov.

After 6... Qa5, White just replies 7. Bd2, threatening Nd5 and Nc7. Black has nothing better than 7... Qd8 when White enjoys a huge advantage in development.


Why have more than one time control per game?

I think these partitioned time controls evolved naturally during the history of tournament chess for two reasons.

To limit psychological warfare. Some chess players are.. let's say difficult. I can vividly imagine the first time when a participant of an important  match refused to make his next move (or even look at the board) because he was so angered that he blundered away a piece in the 10th move but also refused to forfeit and although it was very obvious that he would just let his time run out, there was no rule yet to stop the game right there and everyone had to wait for hours. Or people started to try and abuse the lack of such rule by simply waiting for an entire hour before making the first move simply to unnerve their opponents (who were pondering over which opening they would see etc.)
To make matches more exciting for the spectators. Remember, in private everyone can set their own time control however they like. But for tournament hosts it makes sense to split it into smaller pieces to create more tension. Also, especially casual or even first time spectators might be more at ease with this because it stresses that not every game lasts this long.. you don't have to wait for full 5 hours every time. The time after move 40 looks more like the overtime from other sports rather than "regular" time.


When are both the rank and file required for disambiguation of a move in PGN/SAN?

Yes, it's possible for a piece to need both the rank and file to distinguish it, although it's rare. For example:
[FEN "8/1k6/8/8/5Q2/8/3Q1QK1/8 w - - 0 1"]

1.Qf2e3


Searching for Bobby Fisher maybe.
Trailer: https://www.youtube.com/watch?v=8khmNiamBxo

http://www.imdb.com/title/tt0108065/


I am not an expert, but an active chess player at chess.com and participate in its forums. Yes, chess can be therapeutic. Playing chess involves co-ordination of different mental abilities like strategy, tactics, intuition, visual imagery, risk analysis, control of emotions, etc. Actively playing chess everyday keeps the mind sharp and attentive. In most cases, it has also shown improvements in mental conditions like ADHD, OCD, Depression, etc.

However, over indulgence into anything is bad and playing compulsively over long duration can effect the individual's thought process. Many schizophrenic persons who play chess start visualizing everything including this life, its people and events as chess moves. If the connection with chess is too deep, real life relations with people are affected. These studies are not confirmed, and are said to be more like "adding order to chaos" from schizophrenic mind's perspective.


What's the best plan for white in this position?

White should be winning in this position quite comfortably with the extra piece.

One relatively simple plan is to play 1.Rh3 in order to move the rook to h6 to push the passed g pawn.  If black moves the queen, then g6 is very strong.

For example:

1.Rh3 Bd7 (to defend the loose rook on c8)
2.e3 (Rh6 is not possible immediately because of Qxh6! winning both rooks for the queen) Qf7
3.Ba6 Rc7
4.Qb2 (Δ Qb8+) Bc8
5.Bxc8 Rxc8
6.Qa3+ (and next move white will take the Pa5)

Another plan is to play e3 in order to free the bishop (so that white can make use of the extra piece), but this is less ambitious than playing Rh3 immediately.


Which chess website has the strongest players?

ICC and playchess.com are definitely the top two in terms of the number of registered titled players who play actively.

I was able to find metrics on how many titled players are on ICC, seen here; I couldn't find the numbers for playchess, however they are similar.  Many titled players play on both.


I don't know of any site that specifically does this for particular tournaments. But its very easy to do this yourself! Here's how you do it:

a) Download Scid vs Pc software (http://scidvspc.sourceforge.net/)

b) Download pgn for the Olympiad in Tromso 2014 from TWIC (http://www.theweekinchess.com/assets/files/pgn/olym14.pgn)

c) Open a new DB in SCID vs PC software and import this PGN.

d) Go to Tools > Opening Report

or

Windows > Tree Window

to get the opening tree and the percentages

Here's the output from Olympiad 2014 taken from Scid vs PC:

4.2 Moves from the report position

 Move        Frequency     Score  AvElo Perf AvYear Draw ECO
 1: e4       1649: 43.6%   52.5%  2275  2313  2014  23% B00a
 2: d4       1404: 37.1%   52.7%  2327  2343  2014  29% A40a
 3: Nf3       363:  9.6%   60.0%  2346  2405  2014  24% A04
 4: c4        248:  6.5%   52.0%  2319  2324  2014  27% A10
 5: [end]      45:  1.1%   35.5%  2197  2058  2014   0% A00a
 6: b3         17:  0.4%   55.8%  2329  2202  2014  18% A01
 7: f4         15:  0.3%   33.3%  2152  2127  2014  13% A02
 8: g3         12:  0.3%   66.6%  2411  2399  2014  33% A00t
 9: Nc3         8:  0.2%   62.5%              2014  25% A00l
10: b4          7:  0.1%   78.5%              2014  14% A00p
11: e3          3:  0.0%   33.3%              2014  67% A00k
12: d3          2:  0.0%    0.0%              2014   0% A00j
13: f3          1:  0.0%  100.0%              2014   0% A00b
14: Na3         1:  0.0%   50.0%              2014 100% A00h
15: h3          1:  0.0%  100.0%              2014   0% A00d
__________________________________________________________________
TOTAL:       3776:100.0%   53.1%  2304  2326  2014  26%

4.3 Positional Themes

Frequency of themes in the first 20 moves of each game:
   Same-side castling:             73%    White Isolated Queen Pawn:       8%
   Opposite castling:               8%    Black Isolated Queen Pawn:       8%
   Kingside pawn storm:            15%    White Pawn on 5/6/7th rank:     52%
   Queens exchanged:               40%    Black Pawn on 2/3/4th rank:     34%
   Only one side has Bishop pair:   6%    Open c/d/e file:                50%


Is there published advice on giving simuls?

There are several techniques that a lot of masters commonly use in simuls.

(1) Know the players. Lower rated players can be confused easily with unsound play/attacks, leading to quick wins. You will also know which players to watch out for and spend more time on. Kasparov was very ardent on this point, and was very upset that a 2200 player posed as a 1600 once to get into his simul.

(2) Avoid heavy tactical complications against the stronger players. Simul players use intuition heavily to find good moves quickly. This is not possible in complicated positions, where a lot of time needs to be taken to calculate many lines. This is where the simul master has the most trouble. Generally, steer the game to quieter play, or make sure to only enter complications that clearly favor you. As a corollary of (1) and (2), you should try to defeat the weaker players quickly.

(3) Offer a few early draws. In games where you might not want to play on (games that are more tactical, against stronger players, worse position, etc.) you can offer a draw to reduce the games you play, and focus on doing better on the other games.

These are a few standard tactics that many simul masters use.


At one time, it was believed that all winnable endgames could be won
  within fifty moves. However, in the early twentieth century, some
  exceptions were found, including A. A. Troitsky's (1866-1942) analysis
  of the two knights endgame as well as the endgame of a rook and bishop
  versus a rook. The rules of chess were revised several times to admit
  exceptions to the fifty-move rule for certain specific situations.
  Early on, the fifty-move rule applied to tournament games but not to
  match games (Troitzky 2006:197).

SOURCE: Fifty-move rule


The basic idea of the opening was to snatch e5 pawn, but by playing Qd4 or Qg5 Black returns the pawn with good play.

This forced White to seek other ways of reaching advantage, so he tried with Bxc6 counting on a won pawn endgame. However, things are not so easy since Black has ample of compensation in his bishop pair-remember that bishops are good in open positions-and doubled pawns control a lot of important squares.

Since that try failed, White needed to try something else, and the only option left is bishop retreat. If they play Bc4 Black can transpose into Italian game with the extra temp since a6 has been played. Since a6 is an important move in those lines for Black, he would gain a small plus from the bishop retreat. That leaves Ba4.

With this retreat White keeps pressure on e5 pawn and hopes to force Black into making some concession. Black will do his best to develop and defend without weakening himself but in the end he fails to do so. He must play b5 at some point to release the pressure from the White light-squared bishop. After b5 Black will have  compromised pawn structure on the queen side ( backward c pawn and exposed b5 pawn ) and that is the concession White hoped for.

It isn't much-Black is still OK-but it will guarantee White a long initiative-which is better overall result than what other lines offer.

The reason for this being Black's c-pawn is blocked by a knight so he can't participate in the battle for the center. This enables White to seize initiative in the center by forming d4+e4 pawn center supported with the c3 pawn. Black will lose time to reorganize his queen side in order to counterstrike which gives White time to meet comfortably Black's plan. This usually involves Nbd2-Nf1-Ne3/Ng3 maneuver, preparing king side attack, but can be a4 thrust, or simply a favorable change of the pawn center's type-he can block the position with d5 or open it with an exchange like dxe5 or dxc5.

The last option is the most dangerous for Black so he needs to play very passively for a while before he counter-strikes.

In this Wikipedia link you can see the list of variations. Notice that in the main line there is one thing in common for all the Black's responses-they regroup their queen side to meet White's initiative.

To conclude:

By retreating the bishop to a4 White gains small concession from Black in view of compromised pawn structure which results in White's better control of the center, which results in small but lasting initiative.

Hopefully this answer sheds some light for you.

If you have further questions leave a comment.

Best regards.


What was Nakamura thinking with 62...g5 against Carlsen in Senquefield Cup 2018 rd. 9?

Let's say that Naka doesn't push g5 and instead waits (with for instance Rb7). Then it is white who can play g5+, taking advantage of the pin on the 6th rank. If black plays Kg6, then Kg4 and h5+ is unstoppable. It is clear that white is making progress. If black instead plays Kh5, then gxf6 hxf6, Rxf6 and black has lost a pawn and his king is completely stuck in a box. Rf5+ might be a possibility (taking on e5), black still cannot move the a pawn (due to an immediate Ra6 getting behind it), and again white has clearly made progress.

I believe Naka was sure that these lines were easy wins for white. Better to make the committal, but potentially holdable, g5 move, and try and hold the position with a static pawn structure, than sit and wait only to lose in a few moves.


Is this a popular variation/continuation of the Sicilian Defence?

No, it is not popular. 2.g3 is already only the tenth-most common move. It is apparently technically called the Steinitz Variation in ECO though it's not common enough for that to be a well-known name. It seems to often transpose to the Closed Sicilian, which starts with 2.Nc3 and usually results in White also fianchettoing (putting on g2) his light-squared bishop, though the knight usually ends up on e2, not f3.

In any case, ...b6 as a response is not seen at all in my database. ...b6 is not very common in Sicilians since Black usually tries to get in the more ambitious ...a6 and ...b5.


Creating chess engine, machine learning vs. traditional engine?

If you're trying to make the strongest engine possible, absolutely go for NN engines.

Traditional engines are great - Stockfish is arguably still the strongest engine on the planet on consensus equal hardware - but they are hard to write. These engines didn't get where they were overnight; they took years and years of work. Stockfish for example has been steadily gaining elo for six years. If you start from scratch, you will not get anywhere near Stockfish strength quickly; in fact you are likely to stall several hundred elo from where Stockfish currently is. For comparison some of the strongest single-author engines right now are Ethereal, Laser, and Xiphos (I neglect Houdini & Fire since they aren't open source). These engines are all substantially weaker than Stockfish.

Why are they so much weaker? Two reasons:

At this level, developing an engine takes a lot of computational power. What you do is look through your code and identify an idea that could gain elo. An example idea is, "if we know this move is probably good, do not search branches that reverse that move" (if this doesn't make sense to you, it means there's going to be a high learning curve as well). You then write a patch that implements the idea, and test the modified engine against the previous version. At this level, it takes tens of thousands of games to get a large-enough sample size to tell if the patch is effective. Playing these games takes huge amounts of computational power. Stockfish has access to super hardware: as of time of writing, the Stockfish testing ground Fishtesting is running with 1038 cores. For comparison a typical desktop computer might have 4-8 cores.
The other reason is that Stockfish is backed by many brains. As of time of writing, there are 8 patches written by 5 people being tested. If you look through the patch histories you'll find many more developers who've written patches. I don't know how many active Stockfish developers there are, but it's certainly >20.

On the other hand, NN engines (relatively) easily reach a strength that's well above Ethereal/Laser/Xiphos. See for yourself in the latest Top Chess Engine Championship tournament. Ethereal/Laser/Xiphos are in League 1, which is credible enough, but the engines in the top division (Division P) are:

Stockfish (community-backed traditional engine, runs with Fishtesting)
Komodo (commercial traditional engine, has full-time developers)
Komodo MCTS (commercial semi-traditional engine, has full-time developers)
Houdini (commercial traditional engine, is a one-man effort, hasn't been updated for two years)
Leela Chess Zero (community-backed NN engine, runs with the analog of Fishtesting aka a ton of hardware)
AllieStein (2-man NN engine)
Stoofvlees (NN engine)
ScorpioNN (NN engine)

The last three engines - AllieStein, Stoofvlees and ScorpioNN - are all small collaborations by people who, as far as I know, are enthusiasts like you and not full-time developers. They've gotten to Div P strength after less than two years of trying (all these NN engines only appeared after AlphaZero). For comparison, in the recent history of computer chess there has only been one person who's ever written a traditional engine that competed successfully with Stockfish & Komodo on his own (Robert Houdart, the author of Houdini).

It's true that you probably won't have the hardware to compete with Lc0, but Lc0 takes this much computational power because it's a "zero" engine - it's supposed to play chess without any kind of human knowledge except for rules. You don't need to use the same methodology. You could use e.g. the Stein methodology that uses supervised learning. It's arguably even better than going "zero" - after all it's AllieStein playing in the superfinal, not Lc0.

The upshot is: if your aim is to compete with the best engines in the world, you are far more likely to succeed with NN engines than traditional ones.


I think it's human psychology; we associate forward moves with attack and backward moves with defense. After all, chess originated as an abstract model for a real war.
That said, retreating moves don't need to be unintuitive, as long as we're on the defense. I don't have a specific situation in mind either, but retreating a queen or rook to help defending your king from a mating attack feels familiar.

I've felt this way while doing certain puzzles as it takes me a long time to find the retreating move

That's a good observation: in puzzles, you are almost always on the offense. It's always 'White/Black to move and win material', 'White/Black gives mate in x moves'. In rare cases, it's 'White/Black to move and draw' but even then it's often finding an offensive combination to equalize or force a draw by repetition or stalemate.


What is the long-term idea of the Ruy-Lopez opening?

The answer to this is way beyond my pay grade, but I may be able to say something that prepares you for a better answer.

You are not only comparing two very different opening systems (London System and Ruy Lopez), but you are comparing two different ideas of what an opening system is. The London system was once described by GM Julian Hodgson as the "businessman's opening", ideal for those with little time for study, because once you have played d4 and Bf4 there is not much choice for the other pieces. It can be said without gross exaggeration that the London system can be learned in five minutes.

The Ruy Lopez is much more vague and much more ambitious. The vagueness is why no short answer is possible. The goal is to increase Whites mobility and control of space and to retain the option of where to strike. There are some standard manoeuvers such as c3 and d4,0-0 and Re1,Nb1-d2-f1-e/g3, a4, and others, but Black can often play a big role in deciding the sort of game it will be. He can go for complicated counterattack with the Schliemann, the Open, or the Marshall. He can play more safely, with Steinitz/Steinitz Deferred or more classical approaches like the Chigorin, Keres, Breyer.. In fact one reason NOT to play the Lopez is all of the work required to prepare for everything that might happen. Mastering the Lopez is a lifetimes work.