The TWIC (This Week In Chess) database is your best bet. It's free, has millions of games (many of which are recent and up to date), and is of a high quality.

Here's the link:
http://theweekinchess.com/twic

When you get there, scroll down to the "TWIC Downloads" table and download all the PGN or all the CBV files.

After downloading everything, merge all the games into one database in ChessBase.

Then, you can make this database your reference database (if you don't know how to do this, look up a YouTube tutorial on ChessBase's official channel).


There's more than one mistake in this game, but the biggest one is the last move: 33...Nd3. Probably this is the mistake that was pointed out. It allows White to win a piece (e.g., 34.Rxc6+ Bxc6 35.Nxf7). A better move would have been moving the rook away with 33...Rf5.


Why does stockfish suggest bishop pins on knights early on?

In this particular position, it's not so much that the pin is anything special; there simply aren't many squares where you can put your bishop that don't let your opponent double your pawns. The only other option would be Bxd6, which gives your opponent the pleasant choice of either developing their queen for free with Qxd6 or opting for controlling some central space with cxd6.
In this case, yes, you would take if they play h6, since retreating would again lead to Black doubling your pawns.
Note that your choice of Nxe5 also allows your opponent to double your pawns after ...Bxe5 Bxe5 Nxe5 dxe5.


What is the difference playing against human vs chess engine?

There are two separate problems with your trainingspartner: Strength and style.

Generally you improve the most if you play against opponents slightly stronger than you. You have to adapt by upping your game, but you are still able to adapt! If you are always crushed you only learn to be solid at all costs. You can see this a lot if teenage prodigies play too early against world class opposition: Their game dries out. They systematically unlearn all creative impulses, because every risk taking is punished.
If you play against engines that always beat you, their style doesn't really matter. But if you would play against an engine only slightly stronger than you (which would be a better choice), you would experience the problem, that you adapt to their particular style. Which usually means you get very good at sniffing out tactical pitfalls, but your positional understanding will stay underdeveloped. I know this very well because I played for two years almost daily against a Mephisto board computer before I joined a chess club and it took me many years to stop losing against human opponents who were far weaker tactically.


FIDE threefold repetition and possible moves

Hi I have clarified this over the years with the senior FIDE International Arbiter at the time, Stewart Reuben, who is busy now writing the definitive book on the History of the Laws of Chess.
You focus on the essential point: treatment of possible moves. The TL;DR is that en passant is based on possible moves, castling is based on rights.
At first glance one might think: "Whoa! How inconsistent! Why would they do it different ways?" But actually it makes sense and to my mind is the best way of doing it. Let me see if I can convince you.
In some sense, it might seem "fairest" to look at "possible moves" for both.
However for castling, it might be complex to determine whether a player is going to be able to execute a castling some time in the future. The examples that you give are cool, but relatively simple. The rules would also have to opine whether, in considering the feasibility of actually castling, one can assume that one player is actively trying to prevent this taking place, and how that interacts with the choosing of moves to repeat the position. It's sooo much simpler just to look at the game score and simply observe which kings and rooks have ever moved. The actual executability of castling is irrelevant. The right is lost, as the rule says, after the king or rook moves. A genuine hole in the rule is that the right should also be lost if an unmoved rook is captured on its start square.
On the other hand, en passant is only feasible for one turn. There is no look-ahead required in checking possible moves. If the e.p. can't happen right now because of check or pin, it seems very reasonable that this is indeed a factor in the determination of position. If I try to put a position on the board where the e.p. can't happen due to check or pin, and try to think of it as different from a situation 2.0 moves later, when the e.p. is also too stale to happen, it feels very odd.
After many years of confusion, this is the point of view which FIDE reached under Stewart. The rules could still be clearer, but I think the key step is to understand exactly why "possible moves" should indeed be relevant for one case, but not the other.


There is some analysis at the Kenilworthian blog. See http://www.kenilworthchessclub.org/games/java/2007/caro-adv-h4.htm
http://www.kenilworthchessclub.org/games/java/2011/cavewoman.htm
http://www.kenilworthchessclub.org/games/java/2013/complete-caveman.htm
http://kenilworthian.blogspot.co.uk/2013/03/the-complete-caveman-caro-kann_20.html

Download for the PGN:
http://www.rci.rutgers.edu/~goeller/kenilworth-pgn/complete-caveman.pgn

and also analysis by Dennis Monokroussos here:
http://www.thechessmind.net/storage/chess-posts/anand_shirov_leon2011_day3.htm


Pawn storm, should I start with h4 or g4?

Typically you use a pawn storm to exchange pawns around the castled enemy king and thereby to open lines and diagonals for an attack. Most of the time you want a closed (to some extent) center in order to avoid counterplay in the center.

In this sense your example 4 is not a typical use case for a pawn storm. It might make sense to push the pawns here as well, but the reason for that are concrete tactical motifs. E.g. by playing g4-g5 you seem to force black to exchange the bishop for the knight after which there are ideas with Qg7 mate...

Other than that, it depends a lot on the actual position.

A typical defensive strategy is to block the advancing pawns, thereby halting the pawn storm. In your first example you need to consider that if you play g5 black can block with h5, if you play h5, black can block with g5. To break such blockades, you could consider piece sacrifices (for a pawn or two) or what options you have by pushing the f pawn.

In your second example, if you play g5, black can block with Nh5. In your third example, playing first g4 leaves you with lots of weak dark squares that are eyed by the black queen and knight. Playing first h4 here seems like a much better choice (if you had to decide between g4 or h4).

Some general guidelines (but as mentioned above, don't follow these blindly) depending on the opponent's pawn structure (of course the same applies to exchanged colors):

Pawns on f7-g7-h7

typically broken by playing g6 supported by a pawn from h5. See English attack in the Najdorf Sicilian.
You could also attack with h6, but this really only makes sense if you can make use of the dark squares, e.g. if you have a queen, dark squared bishop... that can enter via the a1-h8 diagonal or if you have a knight that could use the outpost that forms on f6.

Pawns on f7-g6-h7

Break with h5. Most of the time you want rooks on the h-file for the attack, when the h-file opens. See Yugoslav attack in the Sicilian Dragon.
Need to consider whether black can close the position with g5 after you play h5. Therefore in some cases, white wants to play g5 before h5.

Pawns on f7-g6-h6

This is a flexible setup for black, because whether you play h5 or g5, black can always block replying g5 or h5 respectively.
One idea to break it is with a pawn on f4, so as white you aim for h5 but have a pawn on f4 (ready or can play later) in order to prevent the blocking with g5.
Another idea to break it is tactically. Often you end up with such positions, like in your first example, with Qd2, Be3 and Kh7. A typical tactical idea then is to play Ng5 with a white pawn on h4 and a rook on h1. If black takes the pawn hxg5, white opens the h-file with hxg5 check which very often is deadly.

Pawns on f6-g7-h7

You'd go for the f6 pawn by playing g5. Need to consider, whehter black can reply with f5 after which there is not much of an attack.
Sometimes you could follow up with h5-h6 with the idea that the g7 pawn moves and cannot recapture on f6.
See attacks against the Sämisch in the Kings Indian. (i.e. pawn storm by black)

As mentioned these don't work all the time and depend on the concrete position. If you consider the potential for blocking the pawn advance, by closing the structure, which pawn to push often comes naturally.

I'd recommend to look at some of these attacks in actual games. You can use the openings mentioned above as a guideline.


I guess you have to ask IBM, but it's probably not for sale. Right now the custom made computer is on display at the Computer History Museum.


What is the right defensive set-up for the King-Bishop_Rook trio in the diagrammed position?

You forgot to say who has the move in the given position. This is always important.

For example, here if White has the move, he can attack with 1.Bh6, and he will be up a piece.

So we can assume that Black has the move.

In that case he had better play 1...Kh8 to avoid White's attack with 2.Bh6. This move also frees Black's bishop, so White should probably defend the pawn with 2.d4 and Black will probably need to play 2...Rg8. This already answers a couple of your questions (the king needs to go to h8, and the rook will go to g8).

But I leave the other points to better players...


What are the mistakes committed by players who take many years to become an expert?

I can think of three mistakes that a lot of class players who think they're working on their chess make:

They read chess books.

In particular they buy lots of them and then skim them, or study / try to memorize them as if they were textbooks.

Most low level players don't take the time to really get to the bottom of the positions in the books, they don't work with them, only passive consumption.

They memorize openings.

Opening books sell far better than all other types of chess book combined, even though the best they have to offer a class player is a slightly better position against someone who else who had memorized the opening but not quite as far. It's fun to feel like you're playing as a grandmaster, and sure it will lead to some short term improvement, but in the long term this is mostly wasted time.

They don't analyze.

What class player is actually able to take any position and start analyzing it to figure out what's going on? Not many, even though that's what the actual game is about. The best way to improve is just analyze a lot of positions, especially together with a mate (so you can argue and learn from each other), especially your own games. But few put in the work.

I know this because I'm very guilty of all three.


Tool that suggests tactics exercises based on game analysis

Both ChessBase and Fritz do this. I am not sure if others do it too, but this is a great feature of many products from Chessbase.

If you can pick up Chessbase, well and good. Otherwise look into Fritz that might be one version behind the latest version. They sometimes go on sale on Amazon.com and elsewhere.

Here's what you do:

You ask Fritz (or similar engine) to analyze your games.
Select the option that asks if it should create exercises during full analysis.
Once it completes the analysis (it can analyze all 200 of your games if you give it enough time), you can then play through the tactics from your own games.

ProTip: Players will sometimes subset only those games that have exercises, move it to a new database, and play through these exercises. You are essentially training on situations that occur in your own games, a great way to improve.

Hope that helps.


If there is two knight that can go to the same square, how does lichess know which knight I moved in the blind mode?

In algebraic notation, you must specify either the file or rank of the specific piece you'd like to move if an identical piece can also move there.
in the following image, there's a knight on c6 and another knight on e2. There's an arrow going from the f2 knight pointing to the d4 square.

if you'd like to specify this move, then you'd write

N2d4 or
Ned4

In some rare cases you must name both file AND rank. This usually happens when there are 3 of the same pieces on the board, in most cases; 3 queens.
In the following image there are 3 queens, one on d3, another on d7, and another on f7. There's an arrow going from the d7 queen pointing to the f5 square.

this move would be:

(Q)d7f5

The "Q" before "d7f5" is redundant because only a single piece can possibly be on the d7 square so you can just leave it out.


What happened with the Fide online areana?

It is active and the mobile/tablet option is still coming.

Fide Rated tourneys are daily for various time controls.


I'm the Technical Lead of Chessable and the exact person who integrated SF on Chessable.
There are no license issues here because web app is not the same work as a Universal Chess Interface (UCI) chess engine.
Technically you do have the code because the whole UI in JavaScript is being sent to your web browser. Check your Google Chrome network tab, you will find all the JS source code there! We are doing client side JS Stockfish integration, so we can't stop you from copying the minified but working JS code. However, we are not going to give you the code like in GitHub format.
Thanks for trying our SF integration!
https://opensource.stackexchange.com/questions/11490/minified-gpl-code-inside-javascript-webapp is incorrect. The answer failed to address the UCI protocol. All communications via the engine is being done by the UCI protocol. The exact same code without any kind of modification can run on any other chess engines following the UCI protocol. Komodo on chess.com is an excellent example.
The engine and rest of the app is not considered a standalone work, which is what GPL is about. It's like Chessbase shipping their GUI and Fat Fritz 2. Did you ask Chessbase for source code of their GUI? The SF engine in JS is not an executable linking to the app. It's actually you who chooses a browser and run the SF. It does that by running web workers like Chessbase on a standard UCI protocol. Stockfish is not a library or derived work, it's an independent piece of code that your own browser runs it.
PS: Any views here are not my employer's and purely mine.


I've been a "life-long beginner" - my USCF rating hovered around 900 for years and years, and just playing OTB chess wasn't helping to improve my ability because I was losing almost every game, for years (though usually against players rated much higher than me, so it didn't affect my rating much).  It was a long time before I made even a minimal plan to actually improve - so my situation is/was not totally different from yours.  I can't tell you what's best for you.  What I can tell you is what worked for me:

Watching chess classes on YouTube.  The Saint Louis Chess Club has some amazing classes on YouTube.  There was a series of classes called "Beginner Breakdown" that was incredibly helpful for me.  It mainly consists of looking at novice level games - games that have situations that you or I could conceivably get into - and seeing what mistakes were made (and what should have been done instead).  GM Ben Finegold also did a series of kids' classes while he was a GM In Residence at the Club, I found those extremely helpful as well, for the same reasons.  And both of these series are actually entertaining as well as informative, so they kept me engaged very effectively.  Don't feel funny about consuming instructional materials aimed at kids.  It's about level of chess ability, not age (and I know many of the kids that were in these classes when they were recorded were probably rated higher I was).  I can also tell you that the chess instructional videos on YouTube that are the least effective for me are the ones where the "video" is just a screencast of playing through games using Chessbase or something, with an unseen narrator describing the game.
Tactics, tactics, tactics...  Find novice to intermediate level tactics problems and work them.  A lot of them.  On a daily basis.  I worked through all of the problems in the "Tactics Time" books by Tim Brennan and Anthea Carson.  These books were great because they are tactics studies from novice to intermediate level games.  They are not studies from grandmaster games where you have to calculate ahead 6 or 8 moves to see the solution, they're problems from games played by people at "our level", and situations like what we might face - and they're solvable by people at our level of ability.  Going through these books is even easier and more convenient if you get the Kindle versions, and you can work through a couple of problems at a time while waiting in line at the store, riding on the train, or whatever.  Also, the Lichess site / app is a fabulous never-ending source of tactics studies, and I also find that they're easily consumable by novice to intermediate level players, and with the app on a mobile phone you can do a couple of studies at a time, anywhere you happen to be.

This was (and still is) really my whole study plan.  Just doing these two things (and playing OTB chess in tournaments when I have the chance), I (finally!) was able to pull my USCF rating up by about 200 points in the space of a year or so, and my "Training" rating on Lichess is now over 1700 (though how that might correspond to actual play - if it even corresponds at all - is difficult to say).


What is the longest forced win with 3 to 6 pieces (ignoring 50 & 75 move rules)?

Longest known checkmate is in 549 moves, revealed by Lomonosov Tablebases.

You can see the game here.

Plus, you don't need to say "endgame" explicitly. Longest checkmates come from endgame tablebases already. And it's not possible to build a middlegame tablebase practically, because of the exponential space complexity. Let's say there is a middlegame position which is in 12-men tablebase:

---------------------------------------------
5-Men  |  ~7GB
---------------------------------------------
6-Men  |  ~1200GB
---------------------------------------------
7-Men  |  ~140000GB
---------------------------------------------
8-Men  |  ~10000000GB Estimated
---------------------------------------------
12-Men |   Do the math :-)
---------------------------------------------


What is the best move in this puzzle rush?

Did black just play f5 before? Then the right move is exf6 en passant, Bxf6 Rxf6 Rxf6 Qe5+ and win the piece.
[FEN "2b2r1r/2k1qpb1/2p1p2p/1p1pP3/pP1P1RB1/P1N5/2P1Q1PP/5RK1 b - - 1 1"]
[StartFlipped "0"]
[StartPly "3"]

1... f5 2. exf6 Bxf6 3. Rxf6 Rxf6 4. Qe5+


Promotion race between three non-confronting pawns

The two previous answers both suggested that this position is a draw, but I believe it's a win for White.

Stockfish 5 evaluates the position at more than +10 if left to run for long enough (e.g., to depth 40), which sounds pretty decisive, but of course Stockfish isn't infallible. I generated a FinalGen tablebase for the position, but unfortunately it wasn't able to solve the position fully, though it did show that the moves 1.Kf3 and 1.Kf1 lose. Stockfish evaluations for the positions after 1.Kf3 and 1.Kf1 eventually drop below -10, which suggests that Stockfish does understand what is going on here, and its evaluations (at depth 40 or more) should be taken seriously.

The question, of course, wasn't about the game-theoretic status of the position, but about the strategy. The basic strategy is to block the opponent's pawns and aim for zugzwang. White's first move appears to give him a decisive advantage in doing this, provided he starts by moving his king towards the queenside (1.Kd1, 1.Kd2 or 1.Kd3). Here's a sample line:

[FEN "8/pppk4/8/8/8/8/4KPPP/8 w - - 0 1"]

1.Kd3 Ke6 2.h4 Kf7 3.h5 Kg7
( 3...a5 4.Kc4 a4 5.Kb4 b5 6.f4 c5+ 7.Ka3 c4 8.Kb4 Kg7
( 8...Kf6 9.g4 Kg7 10.f5 )
9.f5 Kg8 10.g3 Kg7 11.g4 Kg8 12.h6 Kh7 13.g5 Kg8 14.g6 Kf8 15.f6 $18 )
4.g4 Kh6 5.Kc3 a5 6.f4 a4 7.f5 Kg5
{ The kingside is now mutual zugzwang: Black can't move there without allowing promotion, and White can't move there without losing a pawn. Play therefore switches to the queenside. }
( 7...b5 8.f6 $18 )
8.Kb4 b5 9.Ka3 c5 ( 9...c6 10.Kb4 c5+ 11.Ka3 c4 12.Kb4 $23 { Zugzwang. } )
10.Ka2 b4 11.Kb2 a3+ 12.Kb3 c4+ 13.Ka2 c3 14.Kb3
{ The queenside is now also mutual zugzwang, so Black to move loses. }
14...c2 15.Kxc2 a2 16.Kb2 b3 17.Ka1 Kf6 18.h6 Kf7 19.g5 Kg8 20.g6 Kf8 21.f6 1-0

Black could try to avoid zugzwang by mimicking White's moves, but he can't mimic checks, and this is in any case a recipe for losing a direct race to promote. Here's a sample line:

[FEN "8/pppk4/8/8/8/8/4KPPP/8 w - - 0 1"]

1.Kd3 Ke6 2.h4 a5 3.Kc4 Kf5 4.h5 a4 5.g4+ Kg5 6.Kb4 b5 7.f4+ Kh6 8.f5 c5+
9.Ka3 c4 10.f6 c3 11.g5+ Kxg5 12.f7 b4+ 13.Ka2 b3+ 14.Kb1 a3 15.f8=Q a2+
16.Ka1 c2 17.Qc5+ 1-0


Is there any resource where you can look up a board position and read a number of suggested moves?

If you get ChessBase, there are a number of features that are available when setting up a certain position:

1) With a reference database, you can see the moves chosen in all the games from that position. These moves can be ranked in various ways (e.g., number of games played, rating of players, etc).

2) When turning on an engine to analyze the position, you can see previous engine evaluations of the position (stored from people who analyzed it before). This assumes you're connected to the internet, and that they were as well (so that their engine evaluation could be saved on the cloud).

3) The LiveBook feature allows you to see the number of visits certain moves from that position have had by people who analyzed previously (again, assuming these people were connected to the cloud at the time). This is often a good way to see what the best moves are objectively, as well as the most popular moves played in games (since people could be following a game, which is why they looked at a particular move).


de and fe are normal pawn captures. There is no contradiction in writing de and NxB and Nxe5. The "x" is optional.

It would be unusual and inconsistent to write 4. BxNc6 and 4. ... Nc6 in the following -
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. BxNc6 Nc6

but if we put it in fen then it works -

[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nge7 4. BxNc6 Nc6

Note what the latest FIDE Laws of Chess say about this -

  C.9 When a piece makes a capture, an x may be inserted between:

  C.9.1 the abbreviation of the name of the piece in question and

  C.9.2 the square of arrival. Examples: Bxe5, Nxf3, Rxd1, see also
  C.10.

  C.9.3 When a pawn makes a capture, the file of departure must be
  indicated, then an x may be inserted, then the square of arrival.
  Examples: dxe5, gxf3, axb5. In the case of an ‘en passant’ capture,
  ‘e.p.’ may be appended to the notation. Example: exd6 e.p.

(Italics added for emphasis)


Blitz tournaments (time control around 5 minutes)

https://en.wikipedia.org/wiki/World_Blitz_Chess_Championship
By 1950, the time controls had changed to the familiar five minutes per player, hence the "five-minute game" moniker; the term "blitz chess" would not be coined until the 1960s.

Please search the games on Chessgames. You don't need Chessbase.


Well, according to 7-man tablebase your analysis is correct:

Rxh6 would win, reaching a Lucena position.

81...h4? was a mistake, ...Ra5 was the only drawing move.
Neither player made a mistake in between those two points.

Also, Black could have made it more difficult with 86...Qxc6+, reaching QvR which can be hard to win. White didn't have to allow that possibility.

Of course, there's a big difference between checking tablebase, and giving useful advice to use during a game.  I guess we could say that White should really have seen the chance to go into Lucena; and Black must have miscalculated something when playing ...h4 -- or possibly overlooked the Ra5 plan (it is unusual).


What's the point of attack board inversion?

The Star Trek set I'm familiar with has connection points for the attack boards at the corners of the main boards, but not elsewhere.   So you can have the attack board above the middle board in 4 spots (the corners), or inverted from the upper board, halfway across the middle board.

If the middle board is labeled a1-d4, then the attack board can be placed 'upright' at the outside corners of a1, a4, d1, and d4.   It can also be placed inverted at the outside edge of a3 (near a2) and d3 (near d2) beneath the upper board.

You can also invert a board without moving it along the file.  Moving it between boards requires at least a 1 'peg' move along the file.


If it's randomness you're after, why not try Chess960, aka Fischer Random Chess? The starting position of the pieces is random, which can lead to very exciting games dominated by tactics. There's still no "luck", but at least memorizing openings is less of a factor.


There are other two very important events that follow a different scoring system for the games than the usual W - 1, D - 1/2, L - 0. The first is the Bilbao Masters, you can find information about it on their main site. Although they do not feature short games, the points awarded are W - 3, D - 1, L - 0. The other is the Zurich Chess Challenge, also interesting information is available on their main site. This event features several blitz, rapid and classical rounds, the blitz pgames only count for the initial standings, while others receive different points (W - 1, D - 1/2, L - 0 for the rapid and W - 2, D - 1, L - 0 for the classical) according to the time controls.

There are very few events that feature a distribution of points per game different to the classic one. But if you are only interested in watching rapid chess, I would consider the first part of the Tal Memorial, the Rapid and Blitz Chess Championships and the tiebreaks of the World Cup. All of this events are held anually.


Thoughts on the Robatsch (Modern) Defense?

There is a whole book about this system, The Sniper: Play 1...g6, ...Bg7 and ...c5! by FM Charlie Storey, published by Everyman. It has gotten mixed reviews on Amazon and on the ChessPublishing forums.


King's Gambit, Fischer's Defence 6. Ng1. Wait, what?

Your objective assessment of White's position after 6. Ng1 is quite on the mark.

A. Objectively speaking...

It's hard to see how this position could be good for White.

On the plus side -

White has a good center.
Black's pawn on f4 is weak.
Black's kingside is a bit loose.

On the minus side -

White is a pawn down at the moment.
White's own kingside is weak.

Is a good center worth a pawn? Sometimes it is, sometimes it is not. In this position, it can be shown that at best White is only equal. There is no line that gives White an advantage.

B. Subjectively speaking...

White played the King's Gambit because White wanted a sharp tactical game.

On the plus side -

The White player has successfully achieved a complex tactical position which suits his/her style of play.
Complex tactical positions may not suit the Black player's style of play. Perhaps he/she played 1...e5 with the intention of getting a quieter position.
If the White player is better at tactical positions than the Black player, White has greater chances of winning the game.
The White player may be better prepared in the opening than Black player for this particular line.

One example - Nigel Short, a master of tactical positions, outplayed his strong Grandmaster opponent Vladimir Akopian in this position, playing White.

On the minus side -

Complex tactical positions may suit the Black player's style of play and Black might enjoy these complications.
Black might be as good as White in tactical positions or even better. Thus, White has good chances of losing the game.
Black might be very good at defense and at best White will only manage a draw.
The Black player might be prepared just as well in the opening as the White player or even better in this particular line.

One example- the great champion of the King's Gambit and a master of tactics, Boris Spassky himself, played this position both with White and with Black, winning the game with Black.

It seems to me that White's reasons for going into this line are more subjective than objective. The computer evaluations all favor Black slightly, but that's expected because Black is materially a pawn ahead and computers often are biased towards material. Objectively speaking, here are some lines which show that White doesn't get anything special out of this opening. In my opinion, in the line after 6...f5!?, White is even slightly worse.

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "6...f5!? and Black might be slightly better"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. d4 g5 5. h4 g4 6. Ng1 f5 (6... Bh6 7. Nc3 c6 (
    7... Nf6 8. Nge2 Nh5 9. g3 O-O 10. Bxf4 Nxf4 11. Nxf4=) 8. Nge2 Qf6 9. g3 f3
    10. Nf4 Qe7) 7. Nc3 fxe4 8. Bxf4 (8. Nxe4 Qe7 9. Qe2 Nc6 10. c3 Bf5 11. Nf2 Bh6=+
    ) 8... d5 9. Qd2 c6 10. Nge2 Nf6 11. O-O-O Be6 12. Kb1 (12. Ng3 Bd6) 12...
    Nbd7 13. Ng3 Bb4 14. a3 Ba5 15. Be2 Bc7 16. Rdf1 Bxf4 17. Rxf4 Qe7 18. Rhf1
    O-O-O=+

One sample Grandmaster game in this line -

Hector vs Peter Leko 0-1 1995

4. Bc4!? is a perfectly playable alternative to 4. d4. The point is that Black has to "waste" a move playing 4...h6 first and cannot play 4...g5 directly. If 4...g5, then White get's a better position after 5. h4! as follows -

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "Black cannot play 4...g5 after 4. Bc4!?"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 g5? 5. h4! g4 6. Ng5 Nh6 7. d4 Bg7 8. Bxf4+=

However, I should mention that after 4...h6 and 5...g5, Black is very solid in the mainline resulting position and it's not easy for White to break through.

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "4. Bc4 h6!? 5.d4 g5 and Black is doing well"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 h6 5. d4 g5 6. O-O Bg7 7. c3 Nc6

  Are there reasonable non-mainstream deviations from this line?

Considering the above discussion, I think a reasonable non-mainstream deviation would be to play 4. Bc4 and 5.h4!?, preventing g5. Objectively speaking, White is still slightly worse because of the material deficit, but subjectively speaking, the position is quite complicated with plenty to play for. One idea for White's would be to hold on to the strong pawn center, castle queen side and attempt to put pressure on Black's f4 pawn with moves like Ne2.

      [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
      [Event "5. h4!? is worth a try"]

      1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 h6 5. h4 Nf6 6. Nc3 Nbd7 (6... Bg4 7. d4
      Nh5 8. Ne5! dxe5 9. Qxg4 Nf6 10. Qf5 Nc6 11. dxe5 Nd4 12. Qxf4 Nxc2+ 13. Ke2
      Nxa1 14. exf6 Qxf6 15. Nd5 Qxf4 16. Bxf4 O-O-O 17. Rxa1+/-) (6... c6 7. d4 b5
      8. Bd3 Nh5 9. Ne2) 7. d4 Nh5 8. Qd3


No, it is checkmate. Even if Pb4 is pinned, it still controls square c5, preventing the black king to move there.

Check rules 3.9.1 and 3.9.2 of the laws of chess.

  3.9.1
  The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to the square occupied by the king because they would then leave or place their own king in check.

  3.9.2
  No piece can be moved that will either expose the king of the same colour to check or leave that king in check.

(emphasis mine)

1...Kc5 is illegal.


The problem every time you have such enormous number of configurations, is that any "simple-minded" description of configurations to discard will remove an insignificant portion of the total.

In the case at hand, there are trillions upon trillions of positions with a bare king (for instance), but they represent a small fraction of a percent of all positions.

You still have to deal with the bulk of configurations that make chess hard, so the difficulty of the original problem is still there.


What chess app displays the name of the opening being used in the game?

It isn't likely to be the app you were using, but the Stockfish iOS app displays it:

(if you play more moves, the ECO code and opening name may change, to e.g. A81 Dutch defense)

I suspect many more (or even most) apps do it, or have at least an option to enable it in the settings. Stockfish does not say the name of the opening, though.


Has Anand missed that he is better? Anand vs Andreikin round 12 Candidates tournament

I watched the press conference. It starts at the 4 hr 13 minute mark in this video.
Some quotes from Anand-

"I should play Kd2."
"I suspect White is better"
"but my head was spinning"
"I decided not to tempt fate."
"I was already very tired. The game had taken a lot of energy. I didn't see anything terribly clear. White still has to defend for another 4-5 moves..."

To summarize: Anand was quite tired and although he suspected his position to be better, he didn't see anything concrete for White. In the press conference he mentioned that he saw that Black's pieces would be well co-ordinated while White's would not be so harmoniously placed for the next few moves. Therefore, he decided not to take a risk and go for the draw.
So Anand didn't miss that he is better, but other factors influenced his decision to take the draw.


Most of the writing I've found on the Caro-Kann online simply makes
  vague assertions about how "Black's endgame is better" or how White
  should try [some dubious move or other] to get a good attack in club
  play.

That is not entirely true. This is the case when White overextends himself without any compensation which occurs only if he misplayed the position. In normal case both sides have good chances in an endgame.

  Is that all there is to this opening?

Definitely not!

  I've been trying it out, and I
  find myself unsure of how to proceed in the midgame, on either side of
  the table.

Caro-Kann has lots of typical middlegame positions that require creative thinking and good positional play from both sides in order to reach decent endgame.

Not knowing them "makes your life unbearable" and you will most of the time find your opponent crushing you seemingly effortlessly. Therefore you must learn typical middlegame plans for both sides. Only then, you can start thinking about endgame. And for the record, the endgame holds chances for both sides. Yes, White often overextends with pawns but gets active pieces, especially king, in return which compensates and sometimes matters more than a healthy pawn structure.

If you need help with these post a new question and notify me via comment. I will try to help.

  As Black, should I really just try to trade down to an
  endgame immediately?

No! Just trading down will not help. Who can guarantee that your opponent will accept the trade?

Against such policy I deploy a neat trick:

As soon as I notice that my opponent starts to offer exchanges too often I lure him into a won endgame for me. In a nutshell, the point is to accept the exchanges that are favorable for you as much as you can so he thinks that this will turn into an easy draw. Once he offers bad piece for your good one you just decline the exchange and now you are left with a better piece against worse one which results in an easy win.

This is a standard approach strong players use. Chess would be a poor game if equality could be reached by simply exchanging.

As Black, your main goals are to exchange 2 minor pieces and neutralize opponent's space advantage by performing c5 or e5 break. Those are the exchanges you seek in order to cripple White's attacking potential. Prefer to exchange bishops for bishops and try to leave the knights on. After that you need to evaluate when is suitable for you to enter endgame and when you can stay in the middlegame and start attacking opponent's weaknesses.

  As White, have I no alternative but to try
  something speculative to keep Black from getting to his desired ending
  position?

As White, you can steer the game to a better endgame for you as most strong players do.

It is highly unlikely that your attack will end with a mate against skillful defense but if you maintain pressure you can transpose into endgame where your pieces are more active which should give you a small but lasting advantage. Also, in most lines White has 3 vs 2 queenside pawn majority which ensures better pawn endgame for him. Active pieces coupled with this pawn majority usually win the game as Black needs high technique and precise play in order to hold this type of endgame. The benefit of this approach is that White can not lose the game, but Black usually draws with correct play.

  I see the Advance Variation (2.d4 d5 3.e5) most often, so let's
  restrict the conversation to positions arising from that line.

This variation sums up my previous statements very well.

First off, middlegames can be ultra sharp if White chooses Nunn-Shirov attack and "the last man standing" will have a won endgame most of the time. In this line tactical awareness and combinational skill are important. This is the line your resources referred to. If Black defends successfully the endgame is usually won for him. However, White can create such a strong pressure and choose to enter a better endgame.

Endgames where activity count the most involve rook and knight endgames. Especially in knight endgames space advantage is important.

Second, it can also become positional encounter if White chooses Short line and simply try to maneuver "around Bf5" in which case a complex struggle awaits both of you. Creativity and positional skill is important in that line. Both sides need to be carefull when entering endgame.

Since this topic is to broad to be covered here, I will provide brief explanations and recommend resources for studying at the very end of my post.

NUN-SHIROV ATTACK

White has 2 plans here:

Playing Nf4 at some point, planning a sacrifice on d5. The usual setup is O-O-O + Qe2 + Bg2.
White plays Nd4 preparing f4 and f5. This one is considered more dangerous than the above plan.

Both lines lead to very sharp struggle and one mistake on any side can lose the game.

SHORT LINE

One of the most dangerous tries for White. He simply plays naturally, organizing his pieces to exploit c5 break. If Black plays too slow he will be suffocated, yet if he opens the game White will have an advantage since he is better positioned and better developed. Still, Black players were able to find a way to reach full equality by preparing f6 instead of c5.

CONCLUSION:

Caro-Kann defense is a passive opening for Black that requires patient play in order to equalize. Black reaches full equality over time. White needs to do something with his greater space and aggressive pieces if wishes to win. He can opt for ultra sharp lines or play positionally, aiming for favorable endgame or simply smothering Black.

This is a vast topic to cover here but these books helped me when I needed to learn to play the Black side:

Joe Gallagher-Starting Out the Caro-Kann

Peter Wells-Grandmaster Secrets the Caro-Kann

Cyrus Lakdawala-The Caro-Kann move by move

Lars Schandorff-Grandmaster Repertoire 7 Caro-Kann

Start with Gallagher's book and then try one written by Lakdawala. Once you get some experience playing this opening with both colors you can read the rest.

Hopefully this helps. Leave a comment if you have a question or need further help.

Best regards and good luck.


Note:

It's a good idea for your engine be deterministic. There is no reason to select a move randomly. You would only do it to lower your engine strength. If you make your engine non-deterministic, you will find it very hard to debug and reproduce a bug. My recommendation is not to do it.

You shouldn't modify your engine. You may want to use an opening book, and pick a line randomly. Many chess GUI can do that, for example, the CuteChess software. Arena GUI can do also that.

But if you insist:

Let's take a look at the Stockfish source code.

 Move Skill::pick_best(size_t multiPV) {

    const RootMoves& rootMoves = Threads.main()->rootMoves;
    static PRNG rng(now()); // PRNG sequence should be non-deterministic

    // RootMoves are already sorted by score in descending order
    Value topScore = rootMoves[0].score;
    int delta = std::min(topScore - rootMoves[multiPV - 1].score, PawnValueMg);
    int weakness = 120 - 2 * level;
    int maxScore = -VALUE_INFINITE;

    // Choose best move. For each move score we add two terms, both dependent on
    // weakness. One is deterministic and bigger for weaker levels, and one is
    // random. Then we choose the move with the resulting highest score.
    for (size_t i = 0; i < multiPV; ++i)
    {
        // This is our magic formula
        int push = (  weakness * int(topScore - rootMoves[i].score)
                    + delta * (rng.rand<unsigned>() % weakness)) / 128;

        if (rootMoves[i].score + push > maxScore)
        {
            maxScore = rootMoves[i].score + push;
            best = rootMoves[i].pv[0];
        }
    }

    return best;   }

Stockfish starts multi-PV (not supported in TSCP, so you'll need to code it yourself!)
Compute a random number and add it to the score for each PV
Compare each weighted PV, and pick the best one

You may find the following links useful:

Chess programs that mimic some amateurs
How does a chess engine mimic an Elo rating

Recommendation: Don't do it unless you want to weaken your engine.


Can a player win if their opponent has made 2 illegal moves, but a helpmate isn't possible?

No, the game is drawn, as per article 7.5.5 of FIDE Laws of Chess (emphasis mine):

7.5.5 After the action taken under Article 7.5.1, 7.5.2, 7.5.3 or 7.5.4 for the first completed illegal move by a player, the arbiter shall give two minutes extra time to his opponent; for the second completed illegal move by the same player the arbiter shall declare the game lost by this player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.


How do you implement Alpha-Beta search when you can only compare 2 positions to each other?

This looks right to me, but there are two big caveats, one technical nitpickery in your pseudocode and one much deeper.  The nitpickery is that your net() function shouldn't return a position because comparing positions is expensive; instead it should return something along the lines of 'left is better' or 'right is better' (i.e., a boolean) and your conditionals should be on the value of that boolean.

Your negative infinity case (as well as initiation) can be handled pretty easily with sentinel positions: these are fake positions that serve exactly the same function that −∞ does in 'traditional' alpha-beta, in that (using your pseudocode convention) net(sentinel, P) will always return that P is better for any (non-sentinel) position P.  (The simplest way of doing this is likely with something like an IsSentinel boolean in the position structure, but that's a very code-specific decision).

There's a much deeper caveat, though: you're making the implicit assumption in this pseudocode that your neural network is linearly ordering positions, or at least close enough to linearly ordering them to make this algorithm viable; that is, there are no three positions A, B, C with A<B, B<C, but C<A (where A<B here is just shorthand for 'net(A,B) returns that B is better').  If your neural network isn't at some level returning a value for each position, or at least the results of comparing two values one generated from each position, then it's almost certain that it will run into some measure of this 'rock-paper-scissors' issue.  Unfortunately, there isn't an easy answer there, because the very premise of game tree search (that there is an Objectively Best position) breaks down in that case.  There are certainly ways of trying to tackle that issue, but now we're starting to get into thesis-level research mathematics, in the sense that you could probably get a pretty good thesis out of working through various approaches to the problem...


The main tips are:

1) A pawn on e5 helps. Not only does it prevent ...Nf6, but it also takes away the f6-square from Black's king once it comes to g6 (via ...Kxh7-...Kg6).

2) The greek gift is usually followed up with Ng5+. So if the g5-square is defended by Black, or if you don't have a knight on f3, this idea won't work. In some cases perhaps you could make do without the knight, such as Qh5+ followed by bringing a rook to the h-file, but in the position you posted that doesn't look feasible. Rf3 is prevented by the b7-bishop, while Rf4-Rh4 runs into ...Bxh4.

3) Assuming that a Ng5 follow up is possible, calculate the position after: Bxh7+ Kxh7 Ng5+ Kg6. This is usually what happens in the greek gift, since Kg8 runs into Qh5 (with Qh7# threatened). In the position after ...Kg6, how will you follow up? If you play Qg4, can ...f5 be met well (perhaps with exf6 or Qg3)?

4) Make sure that if Black answers Ng5+ with Kg8, Qh5 would truly be winning. For example, can the king escape in any way, or can the h7-square be guarded?

5) Do a force count of the kingside - who has a stronger armada of pieces concentrated there? For example, in your diagram the f1-rook is opened on the f-file and can be a great contributor. But again, since there is no Ng5+ follow up, the idea doesn't work.


For White, which variation of the King's Indian Defence tends to lead to the most solid, positional, slow, strategic, quiet and closed positions?

According to Joe Gallagher-Starting Out The King's Indian Defense and David Vigorito-Attacking Chess-The King's Indian Volume 2 the most solid line for White in King's Indian is the Fianchetto variation. I tend to agree with it.

Before explaining why, let me just show you the tabya so I can better explain my point of view :

[Title "KID, the Fianchetto variation"]
[fen ""]

1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 O-O 5.Bg2 d6 6.O-O Nc6

After briefly looking through the lines ( there is a vast amount of work to review ) I came to the same conclusion as the above writers based on the following :

Center remains fluid, so Black can not pursue standard ...f5 idea as in other lines;
Because of the first point, and the fact that fianchetto castling is very hard to crack, White king is ultra safe ;
White has more space;

It is not easy for Black to find counterplay, but he can reach equality if he knows how to play this line. Tactical shots are limited to the rook sacrifices along the b-file so Nf6 + Bg7 battery can profit from discovered attack, but otherwise things are positional and dynamic.

There are several sub-variations here, but I would recommend you to play Panno line, since Yugoslav attack is quite sharp and theoretical.

[Title "KID, the Fianchetto variation-Panno line"]
[fen ""]

1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 O-O 5.Bg2 d6 6.O-O Nc6 7.Nc3 a6 8.h3 Rb8 9.e4 b5

White has 2 options here, cxb5 and e5 but I advise you cxb5 as it is safer one. Play will become dynamic, but you have dodged a lot of theory and sharp tactical mayhem from Classical line or Saemish attack... For detailed coverage of this line get Vigorito's book. It is printed in 2011 and is very well written, in my opinion.

Do not forget that KID is a sharp opening and that you can not "sterilize it", you can only reduce the level of sharpness and that is it.


What percentage of the time does White win in the Lomonosov tablebase?

As I do not have access to the full Lomosonov tablebases, here is an answer based on the Syzygy tablebases, which are available online in machine-readable format. I interpret your question as "how often does the side to move win, lose or draw". As the Syzygy tablebases only include positions where White has material advantage, we have to add the statistics with White to move to the statistics with Black to move.
You are going to be disappointed
It seems that there are actually more positions in which the side to move loses. The reason seems to lie in the positions with large material imbalance. For example, consider KQQQQQvK. If you check that link, you will see that:

with White to move, there are 37 099 315 080 winning positions for White (see "histogram":"white":"wdl":"2", the format is explained here)
with Black to move, there are 334 280 290 500 winning positions for White (losing positions for Black), which is about 9 times more! (see "histogram":"black":"wdl":"-2")

The reason for this is that, in KQQQQQvK, most of the positions are checks or checkmates. These positions are legal with Black to move, but illegal with White to move. This strongly biases the statistics to the point that the non-moving side (White) actually has more winning positions than the moving side.
I wrote a Python program to count the wins, draws and loses of the side to move for 3 to 7 pieces. Here are the results. In the spirit of open source/reproducible research, the source code is also included below. As these results are somewhat surprising, I will be happy to be informed of possible mistakes I may have made.
3- to 7-man Syzygy tablebases
Total positions: 945907910147154
Side to move loses: 439240886147124 (46.4359%)
Side to move loss saved by 50-move rule: 1405811609374 (0.1486%)
Draws: 124655757593757 (13.1784%)
Side to move win saved by 50-move rule: 1511382741156 (0.1598%)
Side to move wins: 379094072055743 (40.0773%)

3-man Syzygy tablebases
Total positions: 367868
Side to move loses: 99222 (26.9722%)
Side to move loss saved by 50-move rule: 0 (0.0000%)
Draws: 166126 (45.1591%)
Side to move win saved by 50-move rule: 0 (0.0000%)
Side to move wins: 102520 (27.8687%)

4-man Syzygy tablebases
Total positions: 143702885
Side to move loses: 48712335 (33.8980%)
Side to move loss saved by 50-move rule: 0 (0.0000%)
Draws: 45850555 (31.9065%)
Side to move win saved by 50-move rule: 0 (0.0000%)
Side to move wins: 49139995 (34.1956%)

5-man Syzygy tablebases
Total positions: 32612482961
Side to move loses: 12895319023 (39.5411%)
Side to move loss saved by 50-move rule: 38951980 (0.1194%)
Draws: 7248043033 (22.2248%)
Side to move win saved by 50-move rule: 33205648 (0.1018%)
Side to move wins: 12396963277 (38.0129%)

6-man Syzygy tablebases
Total positions: 6170694290902
Side to move loses: 2634258815181 (42.6898%)
Side to move loss saved by 50-move rule: 8110268813 (0.1314%)
Draws: 1075100392347 (17.4227%)
Side to move win saved by 50-move rule: 7817500373 (0.1267%)
Side to move wins: 2445407314188 (39.6294%)

7-man Syzygy tablebases
Total positions: 939704459302538
Side to move loses: 436593683201363 (46.4607%)
Side to move loss saved by 50-move rule: 1397662388581 (0.1487%)
Draws: 123573363141696 (13.1502%)
Side to move win saved by 50-move rule: 1503532035135 (0.1600%)
Side to move wins: 376636218535763 (40.0803%)

Source code
import json
import numpy as np

fd=open('stats.json')

wdl_keys=('-2', '-1', '0', '1', '2')
wdl=np.zeros((5, 5), dtype=np.uint)

data=json.load(fd)

for key, value in data.items():
    n_pieces=len(key)-1
    for i_wdl in range(5):
        # add WDL data for White to move
        wdl[n_pieces-3, i_wdl]+=value['histogram']['white']['wdl'][wdl_keys[i_wdl]]
        # add WDL data for Black to move
        wdl[n_pieces - 3, i_wdl] += value['histogram']['black']['wdl'][wdl_keys[i_wdl]]

total_positions=np.sum(wdl)
total_wdl=np.sum(wdl, axis=0)
print('3- to 7-man Syzygy tablebases')
print('Total positions: {:d}'.format(total_positions))
print('Side to move loses: {:d} ({:.4f}%)'.format(total_wdl[0], 100.0*float(total_wdl[0])/float(total_positions)))
print('Side to move loss saved by 50-move rule: {:d} ({:.4f}%)'.format(total_wdl[1], 100.0*float(total_wdl[1])/float(total_positions)))
print('Draws: {:d} ({:.4f}%)'.format(total_wdl[2], 100.0*float(total_wdl[2])/float(total_positions)))
print('Side to move win saved by 50-move rule: {:d} ({:.4f}%)'.format(total_wdl[3], 100.0*float(total_wdl[3])/float(total_positions)))
print('Side to move wins: {:d} ({:.4f}%)'.format(total_wdl[4], 100.0*float(total_wdl[4])/float(total_positions)))

positions=np.sum(wdl, axis=1)
for i_pieces in range(5):
    print()
    print('{:d}-man Syzygy tablebases'.format(i_pieces+3))
    print('Total positions: {:d}'.format(positions[i_pieces]))
    print('Side to move loses: {:d} ({:.4f}%)'.format(wdl[i_pieces, 0], 100.0 * float(wdl[i_pieces, 0]) / float(positions[i_pieces])))
    print('Side to move loss saved by 50-move rule: {:d} ({:.4f}%)'.format(wdl[i_pieces, 1], 100.0 * float(wdl[i_pieces, 1]) / float(positions[i_pieces])))
    print('Draws: {:d} ({:.4f}%)'.format(wdl[i_pieces, 2], 100.0 * float(wdl[i_pieces, 2]) / float(positions[i_pieces])))
    print('Side to move win saved by 50-move rule: {:d} ({:.4f}%)'.format(wdl[i_pieces, 3], 100.0 * float(wdl[i_pieces, 3]) / float(positions[i_pieces])))
    print('Side to move wins: {:d} ({:.4f}%)'.format(wdl[i_pieces, 4], 100.0 * float(wdl[i_pieces, 4]) / float(positions[i_pieces])))


What is the highest known lower bound for mate in N from starting position?

This is essentially the question of what is the game complexity of chess. Note that by finiteness, we know that chess is determined, but we do not know if the starting position is a win for white, a win for black, or a draw.  The game complexity of chess is roughly the minimum number of positions we need to check in the game tree to determine the state of the initial position.  This is known as the Shannon number.  In the influential paper Programming a Computer for Playing Chess, Shannon estimated that the Shannon number is at least 10^{120).  Note that the number of particles in the Universe is estimated to be 10^(80).  To answer the question, we actually want to know the height of the game tree  when the initial position becomes determined.  We should also divide this height by 2, since a move in chess is typically considered a white and black move.   The branching factor of the tree is estimated to be about 30.  Thus, we can take the largest N such that 30^(2N) < 10^(120).

Answer. By the back of the envelope, N=40 works.  Coincidentally, this happens to be the length of an average game between grandmasters (although they often resign and do not actually play the game to conclusion).

Edit. The moral of the story is that I was trying to estimate an upper bound for your lower bound.  The first part of Shannon's reasoning is not circular; he says that there are about 30 legal moves from each position, and this number is reasonably constant for the first portion of a game.

Thus, we can estimate the current known value of N (which is really what you are asking, let's call this N') to be at most log_30 (C) where C is equal to the amount of computing power that has existed in the history of mankind.  Even with conservative estimates for C, we get something like  N' at most 20.  In practice, I don't think anyone has carried out this computation very far up the tree, since a priori we know that the computation becomes infeasible after a very short height and it is not necessary to exhaustively search the tree to write good chess programs.

Note however, that you are asking a slightly weaker question, since it is possible that the initial state of the game is a draw with optimal play.  So, one could get bounds for N by writing a program whose goal was to not lose for as long as possible.  We could then play this program against the best programs or human players in the world and see what the length of a shortest game is.  Again, this does not properly answer the question, since we cannot assume that our opponents are playing optimally.  True optimal play requires full knowledge of the game tree, but we have seen that this is computationally infeasible.  Thus, the best we can currently do is approximate an optimally playing opponent with a Kasparov or a very good chess program.


Who is better after this queen sacrifice line?

How did you come up with this line?

Castling kingside on move 13 right into the attack, looks like suicide for black to me.

Also I don't see the point of white sacrificing the queen. Instead of giving black the dream square on e5, I'd first play h4 and only then g5, so that you can recapture on g5 with the h pawn.

Regarding your position at the end of your variation, it is probably just equal. Black does not have any particular weaknesses and also there does not seem to be any immediate threat of an attack on the black king anymore. Compare this with the queen sacrifice Caruana played in the game where he had only 2 pieces for the queen, but complete dominance on the light squares.


KBN vs K checkmate on nonstandard boards

Actually, the bishop and knight mate is not as slippery as it appears.  I have checked this on a tablebase program I wrote.  On a 10x10 board, the side with the bishop and knight (say white) can force mate in at most 47 moves.  White can even force mate on a 16x16 board, in at most 93 moves.  I believe mate can be forced on an arbitrarily large even size board.
First, on an odd size board, I've confirmed that white cannot force mate if the bishop is on the wrong color.  Mate can only be forced in a good corner (one that the bishop controls), so if there are no good corners, mate cannot be forced.
On the 10x10 board, the following is an optimal mate in 47.  The starting position is W: Ka1, Nb1, Bc1; B: Kc2.  1.Bb2 Kb3 2.Ba3 Kc2 3.Ka2 Kd3 4.Kb3 Ke4 5.Kc4 Ke5 6.Bg9 Kf4 7.Kd5 Kf5 8.Be7 Kf4 9.Ke6 Kg4 10.Ke5 Kf3 11.Kf5 Kg2 12.Kg4 Kf2 13.Kf4 Kg2 14.Nd2 Kh1 15.Kg3 Ki2 16.Nf3 Ki1 17.Kh3 Kh1 18.Bf6 Ki1 19.Nh2 Kh1 20.Bj2 Kg1 21.Ng4 Kf1 22.Kg3 Ke2 23.Nf2 Kd2 24.Bf6 Ke3 25.Bg7 Kd2 26.Kf4 Kc2 27.Ke4 Kd2 28.Bd4 Ke1 29.Nh1 Kf1 30.Kf3 Ke1 31.Be3 Kd1 32.Ke4 Kc2 33.Kd4 Kd1 34.Kd3 Ke1 35.Ng3 Kd1 36.Bc5 Ke1 37.Bd4 Kd1 38.Bc3 Kc1 39.Nf5 Kd1 40.Ne3 Kc1 41.Kc4 Kb1 42.Kb3 Kc1 43.Be1 Kb1 44.Bd2 Ka1 45.Nc2+ Kb1 46.Na3+ Ka1 47.Bc3#
This can be played out on apronus.com.
After 23. Nf2, we have a position just like the one shown in Andrew's answer (but upside down: W: Kg3, Bj2, Nf2; B: Ke2).  If we make this board 8x8 by removing the a and b columns (and rows 9 and 10), it would be mate in 14, but here it's mate in 25.  In the optimal line above, the black king never really tries to escape towards the a10 corner.  Let's say he does, with 23. ... Kd2 24. Bf6 Kc2.  This move shortens the mate by one move, with the continuation 25.Kf3 Kb3 26.Ke4 Ka4 27.Kd5 Kb5 28.Bd4 Ka4 29.Kc4 Ka5 30.Kc5 Ka6 31.Kc6.
The black king can only escape as far as a6, and is ultimately still trapped in the good a1 corner.  The rest of this continuation is 31. ... Ka5 32.Nd3 Ka4 33.Kc5 Ka5 34.Nb4 Ka4 35.Kc4 Ka5 36.Be3 Ka4 37.Bb6 Ka3 38.Nd3 Ka4 39.Nb2 Ka3 40.Kc3 Ka2 41.Kc2 Ka3 42.Ba5 Ka2 43.Bb4 Ka1 44.Nd3+ Ka2 45.Nc1+ Ka1 46.Bc3#
Here is the number of moves to force mate on every even sized board from 4 to 16.  4: 15; 6: 22; 8: 33; 10: 47; 12: 64; 14: 78; 16: 93.  Note that on any size board there are a handful of positions that are drawn because black can win a piece immediately.
The following is an optimal mate in 92 on a 16x16 board.  The starting position is again W: Ka1, Nb1, Bc1; B: Kc2. 1.Bb2 Kb3 2.Bi9 Ka4 3.Kb2 Kb5 4.Kc3 Kc6 5.Kd4 Kd7 6.Ke5 Ke8 7.Kf6 Kf8 8.Kg6 Kg8 9.Bg11 Kf9 10.Kh7 Ke10 11.Kg8 Kf11 12.Bi9 Ke10 13.Kh9 Kd11 14.Kg10 Ke10 15.Bg11 Kd9 16.Kf9 Kc10 17.Ke10 Kc11 18.Ke11 Kc12 19.Nd2 Kd13 20.Ne4 Ke14 21.Nf6 Kf13 22.Kf11 Ke14 23.Ke12 Kd15 24.Kd13 Ke16 25.Ke14 Kd16 26.Nd7 Kc16 27.Ne9 Kb15 28.Kd15 Kb14 29.Bf10+ Kb15 30.Nd11 Ka16 31.Nc13 Kb16 32.Kd16 Ka15 33.Kc15 Ka16 34.Kc16 Ka15 35.Na12+ Ka16 36.Nb14 Ka15 37.Nd13 Ka14 38.Nc11 Ka13 39.Bc13 Ka14 40.Kc15 Ka13 41.Kc14 Ka14 42.Bd12 Ka13 43.Na10 Ka12 44.Kc13 Kb11 45.Nb12 Ka12 46.Kc12 Ka13 47.Be11 Ka12 48.Bf12 Ka13 49.Bc15 Ka12 50.Nd11 Ka11 51.Bf12 Ka12 52.Nc13 Ka11 53.Kc11 Ka10 54.Nd11 Ka9 55.Nb10 Kb9 56.Kb11 Ka9 57.Kc10 Ka10 58.Bg13 Ka11 59.Be15 Ka10 60.Nd9 Ka9 61.Bh12 Ka10 62.Nc11+ Ka9 63.Kc9 Ka8 64.Nd9 Kb7 65.Nb8 Ka7 66.Kc8 Ka8 67.Bg11 Ka9 68.Be13+ Ka8 69.Nd7 Ka7 70.Bh10 Ka8 71.Nc9 Ka7 72.Kc7 Ka6 73.Kc6 Ka7 74.Bd6 Ka6 75.Bc5 Ka5 76.Ne8 Ka4 77.Kd5 Kb3 78.Kd4 Kc2 79.Bb4 Kb3 80.Kc5 Ka2 81.Kc4 Kb1 82.Kc3 Kc1 83.Nd6 Kd1 84.Kd3 Kc1 85.Nc4 Kd1 86.Ba5 Kc1 87.Bd2 Kb1 88.Kc3 Ka2 89.Kc2 Ka1 90.Kb3 Kb1 91.Na3+ Ka1 92.Bc3#
It is long, but playing through it definitely helped convince me that white could force mate on an arbitrarily large board.  In the first phase, the white king and bishop can corral the black king while buying tempi for the white knight to catch up.  Once the black king is trapped in the bad corner (a16 in this case), it is shuffled down the a-file with very little breathing room.  Although the procedure is significantly more complicated than a W maneuver, white appears to always be in complete control.


Are there any (free) programs that utilize Chessmetrics or Glicko-2?

Sorry for the lag in answering this question; I just stumbled upon this post. If you want a better response time, then you should contact me through the e-mail given in the help file.

Frankly, as the author or EloRater, I take issue with you declaring that EloRater is rough around the edges, especially since according to your post, you are unable to implement your own. Those who have had the courage to contact me directly, have found me amenable and friendly in resolving their issues. Derogatory remarks posted publically demeaning one's work is not an act of kindness, nor do I take it as such. Consequently, I have chosen to respond brusquely and completely.

Now to answer the question, and to clarify the issue for the uninitiated reader:

Elorater's player input screen allows you to properly place advanced players, this is described in the help file under adding players with the following description:

  Set Initial Rating

  After entering the name, you must select the option of initial rating.
  -Default Adult assigns 1300 as the initial rating (as per USCF rules) -Default Child assigns a rating based on the child's age (as per USCF rules) The formula for computing the rating is 300 + age * 50. You may
  only select the ages listed, which are 4 to 20. Note that 20 or more
  yields the default adult rating. -Level allows you to specifically set
  the perceived skill level of the player this is comparable to
  tournament directors giving a provisional rating to a known chess
  player of some skill. Keep in mind that you should be familiar with
  the relative strengths of players in the common chess community. Most
  apparently advance players, who are not already rated fall between
  advanced beginner and intermediate players. If you are not sure, use
  the default adult setting, which is comparable to advanced beginner.
  -USCF allows you to enter known USCF ratings directly into the system. Use this option if you are entering a USCF rated player.

Furthermore, the USCF rating system, which is available in the program, will move the player more during the first 20 games or so, in an attempt to locate the person accurately. This period is called provisional ratings, and is a feature of the USCF rating system to prevent skewing of the ratings. All the equations for implementing the system, and the logic behind them, including provisional ratings, is described in great detail at the site of Professor Mark E Glickman of Boston University.  The help file provides this link as well as additional notes regarding the program. For your information, the provisional rating mechanism is fully supported by the program.

In short, the program, EloRater, does exactly what it claims: it implements rating system for your club using the USCF rules for rating. This rating system is good enough for the USCF. It should be good enough for your club.  It works great for my club and the majority of the clubs who have opted to utilize my software, judging by the responses of gratitude that I continually get from the users of EloRater over the last 8 years.

Good luck with your club, and good luck finding software that fully meets your expectations.

Jim Garner
(author of EloRater)


What are strategic elements for a correct piece sacrifice?

There is no general rule for a correct sacrifice, however sacrifices are made with different ideas and strategies, such as, to get a huge space advantage, to initiate attack, to cause trouble to the king by opening up it's surrounding pawns, etc. But at the end you have to make sure that your compensation for the sacrifice is pretty good before you actually give up material, and that can only be done by precise thinking in the game. Some of the things you have to keep in mind before sacrificing your material are;

You have good compensation for your sacrifice; i.e. you are gaining something back such as attack, space, gain back opponents material of same value or higher, or mate at some point.
You are defending loss of higher material, avoiding opponent's dangerous attack, defending mate.
Making sure of not going into a neutral position or causing no trouble to your opponent after giving up a sacrifice. This would just make you have less material for nothing.

Here are few examples of famous sacrifices, going through these kind of games will help you understand patterns of sacrifices and ideas behind it. (Make sure to read comments which will appear in the lower box of the game for most moves
) :

The strategical Exchange Sacrifice in Sicilian:

In the Sicilian Defense the exchange sacrifice on c3 is quite typical. In Dragon lines it is almost mandatory to sacrifice a rook for the knight on c3.

What advantages does black usually get? First of all, black gets a ruined pawn structure for white. Secondly, Nc3 was a defender of the central squares d5 and e4, and by eliminating it black can take over the center. Lastly and most importantly, black can launch a dangerous attack on the weak squares around white’s king, since Nc3 was the main defender of the queenside. All of these are major advantages that black gets in return for a material loss. The disadvantage of such an exchange is that if white successfully defends, white might just win because he is up on material. There is also a curious phenomena in such positions: sometimes endgames down an exchange favor black. This is because black’s pawn structure is compact and he usually has no weaknesses. There are no open files for white’s rooks to penetrate, making them not that active.

The following first example shows the attack that black gets for the sacrifice, while the next example shows the endgame.

[Event "WchT 4th"]
[Site "Luzern"]
[Date "1997.10.27"]
[Round "3"]
[White "Arencibia Rodriguez, Walter"]
[Black "Ivanchuk, Vassily"]
[Result "0-1"]
[ECO "B95"]
[WhiteElo "2550"]
[BlackElo "2725"]
[Annotator "Tyomkin,D"]
[Setup "1"]
[FEN "2rqk2r/1b1nbppp/p2ppn2/1p4B1/3NPP2/P1NB3Q/1PP3PP/2KR3R b k - 0 12"]
[Plycount "19"]
[Eventdate "1997.10.??"]
[Eventtype "team"]
[Eventrounds "9"]
[Eventcountry "SUI"]
[Source "ChessBase"]
[Sourcedate "1998.01.31"]

1...Rxc3 { Black destroys the main defender of white's king and sets
the targets of c3 and a3 for attack. } 2.bxc3 Nc5 { Black decides to bring his
knight to attack instead of taking on e4, even though taking on e4 gave black a
slight edge. } ( 2...Nxe4 3.Bxe7 Qxe7 4.Bxe4 Bxe4 ) 3.Bxf6 ( 3.e5 dxe5 4.fxe5 Nfe4 5.Bxe7 Qxe7 { leaving white with a weakened pawn
structure (a3,c3,e5) } ) ( 3.Rhe1 Qa5 4.Qf3 Qxa3+ 5.Kd2 b4 ) 3...Bxf6 4.Rhe1?? { Now black proceeds with his attack. White had to
be very creative to find the right defense. } ( 4.e5! dxe5 5.Nxb5! { the
point of e5, now Qd8 feels very uncomfortable under X-Ray from Rd1 } 5...Ke7! 6.fxe5 Bg5+ 7.Kb1 axb5 ( 7...Qb6? 8.Qg3 Bh6 9.Qh4+ ) 8.Qg4 Kf8 9.Bxb5 Qe7 { Tyomkin,D } ) 4...Qa5 { There is no way white can
hold this position together. } 5.e5 dxe5 6.fxe5 Bg5+ 7.Kb1 ( 7.Kb2 Na4+ ) 7...Bd5 { Black has a wide selection of ways to win. } ( 7...Qxa3 { Ftacnik } 8.Bxb5+! ( 8.Nxb5 axb5 9.Bxb5+ Kf8 10.Qg4 ) 8...axb5 9.Nxb5 Qa5 10.Nd6+ Ke7 ) 8.Nb3 ( 8.Qh5 { Ftacnik } 8...Qxa3 9.Qxg5 Na4 10.Bxb5+ axb5 ) 8...Qxa3 9.Bxb5+ axb5 10.Rxd5 Na4! ( 10...Nxb3 11.cxb3 Qxb3+ 12.Ka1 O-O )
0-1

    [Event "Sochi FIDE GP"]
[Site "Sochi"]
[Date "2008.08.14"]
[Round "13"]
[White "Karjakin, Sergey"]
[Black "Radjabov, Teimour"]
[Result "0-1"]
[ECO "B78"]
[WhiteElo "2727"]
[BlackElo "2744"]
[Annotator ",User"]
[Setup "1"]
[FEN "2r2k2/1p2pp2/p2p1bp1/q3n2n/3NP1b1/1BN1Q3/PPP5/1K4RR b - - 0 20"]
[Plycount "65"]
[Eventdate "2008.07.31"]
[Eventtype "tourn"]
[Eventrounds "13"]
[Eventcountry "RUS"]
[Eventcategory "19"]
[Source "ChessBase"]
[Sourcedate "2008.10.01"]

1...Rxc3!? 2.Qxc3 ( 2.bxc3 { staying in the middlegame might have been a
better option for white } 2...Qc5 3.Rh2 a5 4.Rhg2 Bd7 ) 2...Qxc3 3.bxc3 { at
this stage black would try to improve his pieces, bring his king up and start
pushing his pawn majority on the kingside to create a passed pawn there } 3...e6 4.Bc4 ( 4.Rh2 Ke7 5.Rhg2 Bh3 6.Rd2 g5 { doesn't give much to white } ) 4...Nxc4 5.Rxg4 { this trade does not improve white's position because now
black gets the c4 square for his knight } 5...Be5 6.Rg2 b5 7.Rf2 Kg8 8.a4 ( 8.Rhf1 Ng3 9.Re1 b4! ) 8...bxa4 9.Ka2 Nf6 10.Re2 d5 11.exd5 Nxd5 { now black
has perfectly placed pieces and three passed pawns on the kingside. While
before it was not clear who is better, now it is obvious that black is better,
since white has no counterplay. } 12.Rh3 Bxd4 13.cxd4 Nf4 { winning back one
of the exchanges } 14.Reh2 Nxh3 15.Rxh3 g5 16.Rg3 f6 17.Rc3 Nd2 18.Rd3 Ne4 { now the passed pawns decide the game } 19.c4 Kf7 20.c5 g4 21.c6 Ke7 22.d5 exd5 23.c7 Kd7 24.Rxd5+ Kxc7 25.Rf5 g3 26.Rf4 Kd7 27.Kb2 Ke6 28.Rxe4+ Kf5 29.Re1 Kg4 30.Kc2 g2 31.Kd2 Kg3 32.Ke2 a3 33.Ra1 a2
0-1

EXAMPLES OF TACTICAL SACRIFICES

1- This game was played between Lasker, Emanuel vs. Bauer, Johann Hermann in 1889.
White sacrifices his double bishop to get a whooping attack on Kingside, and also sacrifices rook later in the game but to regain it and also win the game.

[Event "International Tournament"]
[Site "Amsterdam"]
[Date "1889.08.26"]
[Round "1"]
[White "Lasker, Emanuel"]
[Black "Bauer, Johann Hermann"]
[FEN "r4rk1/1b2bppp/ppq1pn2/2ppB3/5P2/1P1BP1N1/P1PPQ1PP/R4RK1 w - - 0 14"]

1.Nh5! { White threatens to
eliminate the king's only defender, and Black can do little to stop him. Bauer,
however, was still unperturbed: he figured that 1...Nxh5 followed by 15...f5
would nip White's shenanigans once and for all. } 1...Nxh5?! { Bauer must have
already written 15.Qxh5 on his score sheet, and contentedly leaned back in his
chair. As you probably already know, Lasker had very different plans. } ( 1...Rfc8 { This move would have been a real spoiler, as White must content himself
with an extra pawn and long-lasting attack after } 2.Nxf6+ Bxf6 3.Bxh7+! Kf8 ( 3...Kxh7 4.Qh5+ Kg8 5.Bxf6 gxf6 6.Qh6! d4 7.Rf3 ) 4.Qg4 { Of
course, Lasker would have had no trouble winning this position as well, but at
least Black could have avoided the double-bishop sacrifice. } ) 2.Bxh7+!! { A
devastating intermezzo. White gives up the pride of his position in order to
damage Black's kingside pawn shell and  -  more importantly  -  mobilize his
queen with check. } ( 2.Qxh5? f5! ) 2...Kxh7 3.Qxh5+ Kg8 { But what now?
The tempting 4.Rf3 is dreadfully slow, and after 4...f6 Black's king will
have a permanent escape route. Of course, Lasker has everything under perfect
control. } 4.Bxg7! { Snap! Crackle! Pop! Amazingly, White gives up another
bishop to destroy the pawn shell. Black has no choice but to recapture, but
his king is sent from the frying pan right into the fire. } 4...Kxg7 ( 4...f6 5.Bh6 Qe8 6.Qg4+ Kh7 7.Qg7# ) 5.Qg4+ { It is crucial to drive the king to
the h-file before mobilizing the rook. The immediate } ( 5.Rf3?? { let Black
off the hook: } 5...Rh8 6.Rg3+ { and now the amazing } 6...Bg5! 7.Qxg5+ ( 7.Rxg5+ Kf6 8.Qg4 d4! ) 7...Kf8 { turns the tables. } ) 5...Kh7 ( 5...Kf6 6.Qg5# ) 6.Rf3 { White threatens Rh3, and it appears that Black is defenseless. To
Bauer's credit, he is able to find an incredibly way to save his monarch from
instant death. } 6...e5! { A miraculous defense: Black's queen will give itself up
to stave off checkmate and eliminate the pernicious rook. As it turns out,
this merely prolongs the agony. } 7.Rh3+ Qh6 8.Rxh6+ Kxh6 9.Qd7! { If
not for this devastating fork, Black would have been very much alive. As it
stands, Black will lose one of his bishops, and White will then have a huge
material advantage in addition to a decisive attack. The rest is fairly clear
without comments. } ( 9.Rf1?! { would have complicated things after } 9...f5! ) 9...Bf6 10.Qxb7 Kg7 11.Rf1 Rab8 12.Qd7 Rfd8 13.Qg4+ Kf8 14.fxe5 Bg7 15.e6 Rb7 16.Qg6 f6 17.Rxf6+! { The last finesse. White crashes through and
wins even more material. It appears that Bauer was simply too shocked to
resign. } 17...Bxf6 18.Qxf6+ Ke8 19.Qh8+ Ke7 20.Qg7+ Kxe6 21.Qxb7 Rd6 22.Qxa6 d4 23.exd4 cxd4 24.h4 d3 25.Qxd3!? { This is some real chessboard sass!
Payback for not resigning, Mr. Bauer. }
1-0

2- Here we will see a rare but important tactic: Interfering with the opponent's pieces.

White has two passed pawns which are close to queening. One is stopped by the black bishop, the other by the rook. White needs to sacrifice a bishop at the intersection of those two lines, forcing Black to decide which pawn to stop - and essentially "pick his poison".

[Date "????.??.??"]
[Result "*"]
[FEN "8/3P4/4k2P/1B2B3/5K2/8/2b5/3r4 w - - 0 1"]

1.Bd3!! { Tadhaa! Sacrificing the bishop but intercepting both blacks Bishop and Rook. Black must capture this bishop one way or another - but either way, one of the pieces' lines will be closed, allowing one of the pawns to queen. } 1...Rxd3 { If the bishop captures the white bishop then the d-pawn will queen. Black could take the d7 pawn with his king, but then White will take the bishop on c2, and win with his passed h-pawn. } 2.h7 { If White played this before, the bishop could just take it. But now the pawns cannot be stopped since the bishop on c2 is blocked } 2...Rh3 { Black stops one pawn... but it's not enough to hold the position. Black had no way to open the bishop on c2, and stop both pawns from promoting at the same time. A truly amazing position! } 3.d8=Q { The rook could not handle both pawns on its own. In this lesson we have learned how to interfere with the opponent's pieces. In endgames, queening a pawn is crucial, and often it is worth it to sacrifice a piece for that end. }
*

Source: Chess.com


How to use dice to determine starting position in Fischer Random?

Several methods to do so are described on Wikipedia. For example:

Roll all the dice in one throw and place White's pieces as follows:

Place a bishop on one of the eight squares (counting from the left, 'a' through 'h' ) as indicated by the octahedron (d8).

Place the other bishop on one of the four squares of opposite color as indicated by the tetrahedron (d4).

Place the queen on one of the remaining six squares as indicated by the cube (d6).

Take the value of the icosahedron (d20), divide by four  (round up), and let 'x' = the quotient, and 'y' = the remainder + 1. Place a knight on the 'x'-th empty square. Then place the other knight on the 'y'-th remaining empty square. In other words, see the d20 as a d5 for the first knight: 1-4, 5-8, 9-12, 13-16 and 17-20. Then for the second knight, look within the group to get a d4. For example, a 20 is in the fifth group and the fourth spot in that group, so place the knights on the fifth square and the fourth square. An 11 is in the third group and the third spot.

You can also use just a d10 since there are only ten unique placements of the knights once the bishops and queen has been placed. Hold one knight on the leftmost square and count one, two, three, four with the other knight on the empty square, then when it loops, move the leftmost knight one square to the right, five, six, seven, then it loops again, eight, nine, and finally with ten both knights are as far right as they go. For example, with a six the knight would be placed on the second of the five empty squares, then the second knight would be place on the second of the three squares that are empty to the right of the knight. Using a d10 in this way after two different colored d4:s and a d6 is a minimal one-roll way since 4×4×6×10 is exactly 960. (And, by subtracting one from each die and multipying with 1, 4, 16 and 96 respectively, then adding those numbers together, you find the number in the Chess960 numbering scheme.) The d8, d4, d6, d20 still give equal chance for all 960 positions, but with every position being represented in four different ways.
Or alternatively (using an additional die and different calculations): Place the first knight according to the value of the d20 die, by counting the five empty squares and looping back to the left whenever reaching the rightmost empty square. Then with four empty squares remaining, do the same for the other knight using the dodecahedron (d12) die. With this method, every position is represented in 48 different ways.

Place the king between the rooks on the remaining three squares.

It is stated (but not proven) that this method (and the others) "generat[e] random starting positions with equal probability".


1. e4 e6 2. Nc3 - how should Black respond?

Well, let's start by looking at the position

[FEN ""]
1.e4 e6 2.Nc3

Why does white play 2.Nc3? Because white gets two options after the standard (!) 2...d5, namely 3.d4 or 3.Nf3 as shown below

[FEN ""]
1.e4 e6 2.Nc3 d5 3.d4 (3.Nf3)

In case black wants to aim for a French system position, I would say that 2...d5 is the best option. In case black wants to go for other types of positions, then it is possible to go for a Sicilian system with 2...c5 as well as more independent routes like 2...Bb4, 2...e5. It is also possible to go for some sort of hybrid after 2...Be7 3.Nf3 g5 4.h3 h5, as shown below. What is the objectively best move? Well, I would say that 2...c5 and 2...d5 are equally strong. While 2...Bb4 seems like an interesting option that needs a bit more research. Or just try it for fun and see where it goes!

[FEN ""]
1.e4 e6 2.Nc3 d5 (2...c5) (2...Bb4) (2...e5 3.Nf3 Nc6 4.Bb5 Nd4) (2...Be7 3.Nf3 g5 4.h3 h5)


Tools for automated notation: webcam movie to PGN

It's 2019-12 now and 5 years after the original question.

Does any such thing exist (webcam/video to pgn converter)? A
prototype maybe?

see

https://github.com/WolfgangFahl/play-chess-with-a-webcam/issues/19
https://github.com/WolfgangFahl/play-chess-with-a-webcam/issues/22
which are both closed by now. See http://lichess.bitplan.com for a game successfully recorded. Join https://gitter.im/play-chess-with-a-webcam/community to discuss

Has anyone attempted such a feat and shared their research?

Yes - so far I found some 35 research papers and some 10 open source solutions and one commercial offering

2.1  http://wiki.bitplan.com/index.php/PlayChessWithAWebCam/Papers

2.2. http://wiki.bitplan.com/index.php/PlayChessWithAWebCam#Open_Source_Projects

2.3. http://wiki.bitplan.com/index.php/PlayChessWithAWebCam#Commercial

http://wiki.bitplan.com/index.php/PlayChessWithAWebCam is another project
aiming at the goals stated by you. The project was started 2019-10-15 and in a few hours I already found a lot of resources e.g. this Question
Some two months later I have updated my answer (see links above)
Are there obvious limitations that make this project unlikely to succeed?
I can only answer from my own experience with a similar project I did 31 years ago see http://wiki.bitplan.com/index.php/MagneticSensorChessBoard1987.
At that time i tried to create a chess board that would detect moves. I used magnets
in the wooden pieces and reed contacts. The key to success was using a chess engine
that new "the rules" to be able to concentrate on movements alone and not having
to detect individual pieces. As outlined in an answer above promotions to non queen
pieces might be one of the edge usecases that are difficult. Detecting the motion of
pieces via picture differences is a well understood problem.

Chess engines and UCI compatible GUIs are also available these days. So the problem
is more an integration problem these days then solving the individual detail issues.

A major obstacle is the difference between a "prototype" and a product. See e.g.
http://www.nandanbanerjee.com/files/ICCVR-08AUG12-011%20paper.pdf

a paper that is even older than this question but far from a product that you can buy
at a reasonable price.
Would you buy it if it existed?

Yes. When I bought a new chess board a few days ago I was looking for one that
could record moves and it was still around 500 EUR. As it looks the hardware cost
will be well below 150 EUR these days including a decent chess board and pieces.

The software might well be opensource and free (as in free beer) soon. I'll update
this answer accordingly.


Since I'm a 1.d4 player, my first two moves as White would be 1.d4 and 2.c4. After that position, Stockfish gives an evaluation of +0.59 if Black plays ...e6. I would definitely enjoy playing this as White since the threat of playing e4 at any time prevents the Nimzo and Dutch. Black best option is to settle for a QGD one tempo down by playing ...d5 on the next move, but this would be very comfortable for me. So I'd probably choose White, but it's not an easy decision.

That being said, it's not close to winning for White. An extra move just guarantees a pleasant edge.

With three initial moves, I would go for 1.e4, 2.d4, 3.Nf3. Stockfish gives a +0.99 evaluation, and it would be very tough for a human to defend as Black in a practical OTB game. This seems on the verge of winning for White, but still not a definite win.


Is the "Pawn Box" possible in standard chess?

As @BrianTowers showed, it can be done. Here’s a shorter proof game for the fun of it.

[FEN ""]

1. h4 g5 2. hxg5 f5 3. g4 Nf6 4. gxf6 d6 5. gxf5 Be6 6. f4 Bb3 7. axb3 c5 8. e4 c4 9. bxc4 d5 10. cxd5 e6 11. dxe6 Na6 12. b4 Nc5 13. bxc5 Qd5 14. c4 Bd6 15. cxd6 Rf8 16. cxd5 Rh8 17. d4


In the Damiano Variation of Petrov's Defense, should white play d4 or f4?

White has the advantage no matter which pawn is moved next, 6. d4 or
  6. f4 (there is no way to keep the knight, but after the exchange white is up a pawn).

My initial reaction is pretty much the same as yours. You'd have to be a very poor player to even think of playing this as black. However, we are both wrong! Much stronger players than me play it as black and even win sometimes.

One of these is Austrian IM Friedrich Volkmann.

Here are 3 of his wins.

First against a stronger opponent

[FEN ""]
[Event "EU-ch 4th"]
[Site "Istanbul"]
[Date "2003.06.05"]
[Round "6"]
[White "Nedev, Trajko 2518"]
[Black "Volkmann, Friedrich Karl 2435"]
[Result "0-1"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe7 5. Qxe4 d6 6. d4 dxe5
7. dxe5 Nc6  8. Bb5 Bd7 9. Nc3 Qb4 10. Bc4 O-O-O 11. a3 Qa5 12. Bf4 Bb4
13. O-O Bxc3 14.  bxc3 Be6 15. Bd3 Qxc3 16. Rab1 Ba2 17. Rbd1 Kb8
18. Rfe1 h6 19. Bg3 Rd4 20. Qe2  Rhd8 21. f4 g6 22. Rc1 Bc4 23. Bf2 Rxf4
24. Be3 Nd4 25. Qd1 Rh4 26. Bf2 Rh5 27.  Re4 Be6 28. Rb1 Nc6 29. Qf3 b6
30. Rc4 Bxc4 31. Qxc6 Rxd3 32. cxd3 Qxd3 33. Rc1  Rh4 34. h3 Rf4
35. Re1 Rxf2 36. Kxf2 Qd2+ 37. Kf3 Bd5+ 0-1

Against a much weaker opponent

[FEN ""]
[Event "ICS Anniversary op"]
[Site "Fics Internet"]
[Date "2002.01.15"]
[Round "7"]
[White "Alaimo, Riccardo 2158"]
[Black "Volkmann, Friedrich Karl 2414"]
[Result "0-1"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe7 5. Qxe4 d6 6. d4 dxe5
7. Qxe5 Qxe5+  8. dxe5 Bf5 9. Bd3 Bxd3 10. cxd3 Nc6 11. O-O O-O-O
12. f4 Nb4 13. Nc3 Bc5+ 14.  Kh1 Nxd3 15. Ne4 Bd4 16. Rb1 f6
17. exf6 gxf6 18. Bd2 Rhe8 19. Nc3 Nf2+ 20.  Rxf2 Bxf2 21. Rd1 Rxd2 0-1

Against a slightly weaker opponent

[FEN ""]
[Event "EU-chT (Men)"]
[Site "Leon"]
[Date "2001.11.14"]
[Round "8.2"]
[White "Haznedaroglu, Kivanc 2328"]
[Black "Volkmann, Friedrich Karl 2414"]
[Result "0-1"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe7 5. Qxe4 d6 6. f4 dxe5
7. fxe5 f6 8.  Bc4 Qxe5 9. Qxe5+ fxe5 10. d3 Nc6 11. Be3 Nd4
12. Kd2 Nf5 13. Bf2 Bd7 14. Nc3  O-O-O 15. Rae1 Re8 16. Bf7 Re7
17. Bd5 c6 18. Be4 b6 19. Rhf1 g6 20. Kc1 Bh6+  21. Kb1 Rf8
22. Bf3 Ref7 23. Ne4 Kc7 24. c3 Nd6 25. Ng3 Bh3 26. Bg1 Nf5
27. Be4  Nxg3 28. Rxf7+ Rxf7 29. hxg3 Bf5 30. Rf1 Kd6 31. Kc2 Ke6
32. Rf3 Bxe4 33. dxe4  Rxf3 34. gxf3 Bf8 35. b4 h5 36. Kd3 g5
37. Bf2 Be7 38. a4 h4 39. g4 c5 40. Kc4  cxb4 41. cxb4 h3
42. Bg3 a6 43. b5 a5 44. Kd3 Bc5 45. Ke2 Kd6 46. Kf1 Be3
47. Ke2 Bf4 48. Bxf4 exf4 0-1

After those games I'm not so sure that it is a blunder. The statistics still favor white by something like 40% white wins to about 20% black wins, so it looks like a better opening for white but psychologically I can see how it would be good for black. Black gets the kind of position he knows and is comfortable with while white thinks he is playing an idiot and so is maybe more likely to play badly.


Looking for an opening where stockfish puts out a queen early

If you can en passant any enemy piece and the engine doesn't know about it, you don't need to trick Stockfish into bringing its queen out early. You can play almost any way you want and let the game come to you eventually.
I guess a quick example can come from the Alekhine Defence. After 1.e4 Nf6 2.e5 Nd5, if I understood correctly you can put yourself a piece up with 3.exd6 e.p


Generally the approach to estimate an Elo rating directly from the games, is to calculate the accuracy of the moves compared to the best move given by an engine.

There is a correlation between accuracy and playing strength, which can be used to calculate an Elo estimate from the accuracy. This idea is laid out in this paper by Ken Regan.


What does an equal odds game look like for a GM vs an engine?

As of right now, the "equal odds" between a GM and an engine is about two pawns. I believe Hikaru Nakamura made that comment at some point in this match (I did not watch the entire video). For another perspective, this is what happened when GM David Smerdon played against Komodo with knight odds (GM Smerdon won 4-1).
Note that two pawn odds (White starts without b- and c- pawns) gives a starting eval of about -3.0, while knight odds (White begins without the b1-knight) gives a starting eval of about -5.0. Comparatively 4-tempi odds (White plays e4, d4, Nf3 and Nc3 at start of the game, before Black gets to move) is only about +2.
Do note that giving White five "free" tempi leads to a forced win. For five non-free tempi, you'd have to analyze the specific position.


Is there a forced mate/ winning advantage?

Congratulations on a fine win. I see you have dominated the center with your knight which is backed up by doubled rooks on an open file.  Your king is in a safe position, compared to black's drafty King position. Black's queen is passive though not poorly placed. One of black's rooks is still in the box and is undefended.  It's vulnerable.  The other rook is also undefended and passive. But at least it is offering a feeble defense.

If you dilly-dallied, Black could move his knight to the awesome c3 square. So I am glad you did not do that. Also, if the pieces suddenly disappeared from the board, he would have a passed pawn on the f-file which could be fatal for you.

This position proves the adage, "If you find a good move, wait, and find a better move."  White wins with Qh4.  I'm sure you can win this game by force but I can't find a mate. It's amazing how resilient even crummy positions can be, if the losing player is willing to play until the bitter end.

This statement set off my danger alarm:

  QxR down the exchange and threatening to take more.

Being up the exchange is not a clear-cut win. You need to see the 'more' before assuming you're going to get the full point.

Qh4 is spot-on in that it forwards an agenda (exploit the drafty house) while hitting the lose rook. What's not to like?  But what I think you have missed here is the wretched state of the g6 pawn.  What if you double up on it with Qg2.  Now you're threatening to denude the king even more, while hitting the lose liability, oops I mean rook, on a8. Because Black's rooks are lose, you can move with tempo. It's like getting free moves.

[FEN "r5k1/p1q5/5rp1/2p1Np2/1p1n1P2/1P1PR3/P1P2Q2/1K2R3 w - - 0 1"]

1. Qg2 Raf8 2. Nxg6 (2... a6?? 3.Ne7+ Kf7 4.Qd5+ looks_strong) Rxg6 3. Qxg6+ Qg7 4.Qd6

The a6 move is a throw-away to show what can happen if Black plays poorly. It's what's coming if he does not take evasive action.

The main line sees you getting an exchange and a pawn. Super easy, too, and offers Black nothing in return.  Now your queen dominates black's undefended queenside. The c5 pawn will likely fall, leaving the Knight trapped. If he saves the Knight, you probably get the b4 pawn if you want it.  NOW if the pieces drop off, you have connected passed pawns.

Black's king will never be safe with white's queen and rooks on the board. This means he must always defend against fast checkmates and getting pieces pinned against the king. He's going to be down material and defensive. Further, I don't see how black holds the c5 pawn and he's in danger of losing the knight which is hemmed in.

Edit - I like to run positions in Stockfish (a chess engine.)  I let this one run. 20 minutes into its analysis, it switched black's first response from Raf8 to Nb5.  That is, it advocates that black simply drop the rook on a8. 1. Qg2 Nb5 2. Qxa8. wow. It rates the initial position as a crushing win for white. What is important to realize is that the moves are there if you're clever enough to find them.


Kraemer vs Bacrot, 2013. Is this same-color bishop endgame won for black?

Is this same-color bishop endgame actually won for black?

Black has faster king, but he has permanent weakness in view of the a4 pawn.

His bishop is bad and kingside pawns are on the same color he is. Although kingside pawn formation can be changed to suit the bishop, he will still be unable to attack the opponent because White can also change his kingside pawn structure to favor his bishop.

Furthermore, White king is fast enough to cut off opposing king with joined cooperation of his bishop and pawns.

Since Black king is faster, Black will be able to exchange weak a4 pawn if this one becomes a problem, thus the position will result in a draw.

[Title "Kraemer-Bacrot,2013"]
[StartFlipped "0"]
[fen "8/3b1pkp/6p1/8/p7/7P/1P2BPPK/8 b - - 0 1"]

1...Kf6 ( 1...g5! 2.Kg1 Kf6 3.Bc4! Be6 4.Bb5! Bb3 5.Kf1 Ke5 6.Ke2 Kd4 7.Kd2 Bd5 8.g3 Bb3 9.h4 f6! 10.Bd3! h6 11.f4! gxf4 12.gxf4 Bd5!? 13.Bc2 Bb3 14.Bd3= ) 2.Bc4! Be6 3.Bb5! Bb3 4.Kg1 Ke5 5.Kf1 Kd4 ( 5...g5!? 6.Ke1 Bd5 7.g3 Bb3 8.Kd2 Ke4 9.Bc6+ ( 9.Bd3+ Kf3 10.Ke1 h6 ( 10...h5 11.Be2+ Kg2 12.Bxh5 Kxh3 ) 11.Be2+ Kg2 12.Bf1+ Kh2 13.h4 gxh4 14.gxh4 f6! 15.Kd2! Kg1 16.Ke1 Kh2= ) Kd4 10.h4= ) 6.Ke1 Kc5 7.Be8! Bd5 8.g3 Kb4 9.h4! Kb3 10.Kd2 f6 ( 10...Kxb2 11.Bxa4 ) 11.Kc1 Bf3 12.Bf7+ Kb4 13.Kd2 Bg4 14.f4 Bf3 15.Bg8 h6 16.Bf7 Be4 17.Kc1 Bd3 18. Kd2 Bf5 19.g4 Bxg4 20.Bxg6 Be6 21.Bd3 Bf7 22.Kc2 Bc4 23.Be4 Bb3+ 24.Kd2 Bg8 25.Bd3 Bd5 26.Kc2 Bb3+ 27.Kd2 Be6 28.Kc2 Bf7=

No matter what Black tries to complicate the game, thus creating winning chances, we see that White can simply decline the offer and keep things simple which results in a draw.

Hopefully this answers your question. If you have further questions leave a comment.

Best regards.


Standard endgame chess positions which are helpful to learn

For sure KP mixes like KP vs KP, KPP vs KP etc: learn to count moves to promotion, study opposition and zugzwang.

Later KRP+ mixes: like KRP vs KR till KR4P vs KR3P are all quite common, far more relevant than say KBN vs K, not easy though, especially 4 vs 3 pawns.

A bit less common KNP+ and KNB+. still relevant.

Finally endgames where one side has a piece and the other only pawns: this are quite common at lower levels.


In this position why shouldn't the knight capture the rook?

Black's idea is to play Re2+ at the right moment. If, for instance, White takes the rook with 19.Nxf8 Kxf8, there is no way to prevent Black from playing Re2+ later, winning the Queen (after Qxe2 Bxe2 Kxe2, not hopeless but slightly good for Black possibly; in practice Black might pick up g2 before doing this), reason being that Kf1 walks into a discovered attack. Because of that, White chooses to play 19.Nxc5 instead to capture the bishop on a6 and thereby prevent Re2+.
Although the difference between taking the rook or going for the bishop is not that big, both moves can be considered reasonable.
EDIT: In fact a deeper analysis reveals that taking the rook is in fact to be preferred since after 19.Nxc5 Qc6 20.Nxa6 d4! apparently leads to an advantage for Black, threatening Qxg2 and thus forcing 21.Qf3 after which Qxa6 now leads to a Black advantage due to having forced the enemy queen away  from the Queen side defenses. So I suppose you were right after all to consider 19.Nxf8 stronger.


ChessBase products only support two protocols:

1) Their own proprietary (used by the .eng engines)

2) The UCI (used by by many commercial / open source engines)

You must see a "Create UCI Engine" option in either Fritz or ChessBase (I used it all the time to make tournaments between engines).

I also use Arena for engine tournaments and supports both UCI / Winboard. You should be able to use UCI engines in both Arena / ChessBase.

Some notes:

There are adapters for Winboard to UCI like Good UCI to WinBoard adapter (but I don't have seen the opposite).
I have learned that whenever I have to buy a commercial engine (like Houdini or Komodo) I prefer to not buy it thru ChessBase (because they only provide the .eng and only works in their own interface).


What counter-measures for cheating exist?

There have been tournaments that require the players pass through a metal detector, and play in an isolated environment with no spectator contact.  Still, there was the whole Toiletgate incident during the 2006 Topalov-Kramnik match, so even these measures might not seem like 'enough.'  Besides resorting to strip searching the players, what else can be done except isolate them from the outside world during the games?


Unfinished Chess game between Viswanathan Anand and Garry Kasparov

High level players usually resign when they have a lost position. There's no point in continuing the game for thirty more moves when defeat is inevitable. Checkmate is actually a rare occurence in elite games. You'll find the same thing in more modern games, too.
While players have the right to keep playing, it is considered bad etiquette to not resign when a player has no realistic chance of scoring.


From the FIDE Laws of Chess, §3.1:

  It is not permitted to move a piece to a square occupied by a piece of the same colour. If a  piece  moves  to  a  square  occupied  by  an  opponent’s  piece the  latter  is  captured  and  removed  from  the  chessboard  as  part  of  the  same  move.

(emphasis mine).

So you can't capture your own piece.


Is it illegal to write clock time in the score sheet during tournaments?

According to the FIDE rules, it is not forbidden; clock times are actually explicitly stated as one of the items that a scoresheet may contain. See the following excerpt (emphasis mine):

  Article 8: The recording of the moves

  8.1

  a. In the course of play each player is required to record his own moves and those of his opponentin the correct manner, move after move, as clearly and legibly as possible, in the algebraic notation (Appendix C), on the ‘scoresheet’ prescribed for the competition. It is forbidden to write the moves in advance, unless the player is claiming a draw according to Article 9.2, or 9.3 or adjourning a game according to Appendix E.1 a.

  b. The scoresheet shall be used only for recording the moves, the times of the clocks, offers of a draw, matters relating to a claim and other relevant data.

  c. A player may reply to his opponent’s move before recording it, if he so wishes. He must record his previous move before making another.

  d. Both players must record the offer of a draw on the scoresheet with a symbol (=).

  e. If a player is unable to keep score, an assistant, who must be acceptable to the arbiter, may be provided by the player to write the moves. His clock shall be adjusted by the arbiter in an equitable way. This adjustment of the clock shall not apply to a player with a disability.

Note that the rules above pertain to competitions starting on or after July 1st, 2014. The older version has the same rule placed in article 12.4. (thanks to @chaosflaws)


Looking for the complete game Sibilio-Mariotti, Ravenna 1982

All games from Tim Krabbe's website are available in the little player on the right side of the page (there is a chessboard, game navigation bar and a box from which the games can be chosen).
For the sake of the question and since it is quite an entertaining game, though:

[White "Sibilio"]
[Black "Mariotti"]
[Event "Ravenna 1982"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. e4 e6 2. Nf3 d5 3. e5 c5 4. b4 cxb4 5. d4 Nh6 6. a3 bxa3 7. c3 Nf5 8. Nxa3 Nc6 9. Nb5 a6 10. g4 Bd7 11. Bg5 Be7 12. gxf5 axb5 13. fxe6 fxe6 14. Rxa8 Qxa8 15. Rg1 Qa3 16. Bxb5 Bxg5 17. Rxg5 Qxc3+ 18. Kf1 O-O 19. Bxc6 Bxc6 20. Kg2 Ba4 21. Qe2 Bc2 22. Ne1 Bxe4+ 23. f3 Rxf3 24. Nxf3 Bxf3 25. Qxf3 Qd2+ 26. Kh3 Qxg5 27. Qf8+ Kxf8 1/2-1/2


The exact rules are on the tournament rules page. If your schedule does not permit you to play every game or you just need some rest, you can can take a half-point bye instead, getting 1/2 point instead of playing. This is pretty much the same bye rule used in every Swiss System tournament.


When did Bobby Fischer move from New York to California?

It’s just a guess, but it could be because he started following Herbert Armstrong who was in California. Fischer did donate lots of money to him and was reported riding in his jet plane with him. As I recall, it would have been in the 70s or possibly the 80s.


Can you move from one side being checked to other side in stalemate?