Is it too late for me to start professional chess?

I will write from the perspective of my home country, USA. If you are in a different country, you can likely find parallels.

  Is it too late for me to be ambitious?

It is never too late to learn more.

  I am aiming for a GM title in 5
  years time. I don't doubt my learning abilities or memory, as is
  usually the case for the older aspirants, since I solve problems for a
  living (computer science/ mathematics).

5 years is not much time from going from an amateur skill level to earning a GM title. I am also a CS/Math guy. A good one. It doesn't always translate to chess as my lofty 1650 USCF rating will tell you.

  How many hours do serious players put into preparation and analysis? I estimate to be
  able to put in about 30-35 hours a week.

That should do it.  Expect to be very good in 5.5 years of extremely focused work. (10,000 hours for mastery...)

  How many tournaments/ games does it take to be a GM?

Unanswerable. But expect hundreds and hundreds of serious, focused games. Not blitz. Tournament speed games.

  Is 5 years too less? I am imagining playing 3-4 tournaments a year.

It is hard to image anyone with no over-the-board rating can become a GM in 5 years. A few young adults do it and they get their names in Chess Life for it. You need to be playing serious games every week. Plan on some sort of a local tournament every month, plan on 3 or 4 nights at your local chess club playing opponents as serious as you are.  And get an instructor.

  How does one find the right tournaments? I don't want to travel too far. Also I don't
  want to pay hefty fees to enter tournaments. And the participants should be all roughly
  around my level or slightly better.

USCF tournaments are generally very affordable as chess is not a profitable venture for 99% of the participants. Check the USCF web site for chess clubs near you.

Becoming a professional at anything worthwhile is not cheap. Expect to pay thousands annually in hotels, food, transportation, instruction, equipment, entry fees, and so forth.  If you aren't willing to invest you should temper your expectations.

  How much a rating of 1900 on chess.com translate to in real?

It doesn't. There is no reliable way to compare that rating with any other rating.

You've set yourself a lofty goal.

I recommend you play some rated games and earn a rating. This will tell you how hard you'll have to work to become a GM. Let's say your rating is 2000 USCF.  That's an very respectable 'expert' rating. To be a GM, you would have to improve to about an 2600 USCF.   So you'll need 600 points. Every 400 points of improvement means that your old self would have no appreciable chance of defeating your new self. So you'd have to make a Herculean 400 pt improvement, and then become dominant over that new self.


First, you have to understand that computers sometimes play non-human moves because they see things that humans most times do not. It probably sees threats to the white king based on the black bishop pair.

In this position, white is just lost, and those bishops on d5 and c5 working together are incredibly strong, so trading off one of them is desirable. What makes it a little strange is that it gives black connected passed pawns, but they are hard to maintain, let alone advance, due to the active white rooks, and unfortunate black Ra8, but it still does not change the outcome.

Also, the Ra8 is not lost to Nd5 cd; Rg8 Bf8; Rf1 Ke7, but it does tie black up some, which is another reason that Nd5 was best. It is hard to finish his development.

 [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]

 1. Nxd5 cxd5 2. Rg8+ Bf8 3. Rf1 Ke7 4. Rf5 {with a little counterplay that requires accuracy from black} Rf6! 5. Rxh5 (5. Rxe5? Kf7 6. Rh8 Bd6 7. Rxa8 Bxe5+ 8. Kg2 Bxb2 9. Rxa7 Kg6-+)  Rc8! 6. Rxe5 Kd7!! 7. Rd5 Bd6+ 8. Rxd6+ Rxd6 9. Rg7 Kc6 10. Rxa7 Kb6 {with an easy win from here}


A word for the resulting piece of a promotion?

It is not clear what you are after, if you are looking for a generic term describing a piece that was added in the game during the play then you seem to be after something that is not embedded in the game. There is no such word and there cannot be any because if there was such a word it would suggest that the new piece is somehow different from an equivalent piece that was there at the beginning of the game. But that is not the case the piece into which the pawn is promoted is absolutely equivalent to another piece of the same name and colour.

Occasionally it may be useful to refer to a piece that has just been added (but this you seem not to want to do). There are several reasonable suggestions in the comments I will just add that the Laws of chess use "the new piece" for this purpose (as in "... and the effect of the new piece is immediate" or "...when the player's hand has released the new piece on the square of promotion...", articles 3.7.5.3 and 4.7.3, respectively).


A way to add an "opening names" column to the SCID game list

There doesn't appear to be a way to do this directly. There's a predetermined list of columns available, and this isn't one of the choices. And, while the ECO Code field will allow you to type in a different ECO code than the one it auto-detects, it won't save anything other than a valid ECO code, so you can't just type in something like "Sicilian" or even "B96Najdorf" and have it work; the first will be ignored and the second will be truncated to "B96".
One option is to take a column that displays free text, like "Event" or "Site", and use that for the opening names instead. But this takes a lot of manual work, and you lose the information that used to be in that column.
Otherwise, SCID is open source, so you could modify the code yourself to add an opening name column, if you know programming.


At one time, there was an annual rating list published each year in the January issue of Chess Life.  They don't do that anymore, and I'm not sure if they still did it in 1998 (or, I assume what you'd really want would be such a list that would have been published in January 1999, which would have the year end ratings for 1998).  If they still did, if you can find a library that has back issues of Chess Life, you could look there.  Or, House of Staunton / USCF Sales has the January 1999 back issue available for $1.00.

If you can find someone who has been a USCF TD for that long, and if they're a bit of a packrat, they might still have the 1998 annual rating list, though you'd have to sort it yourself.  And it might be on floppy disk...  I looked on the USCF web site in the TD/Affiliate area, and they don't have rating supplements online that go back nearly that far.


Importing and exporting games to and from Droidfish
Hold down on the board, and a set of options appear:

Click on Share Game or Clipboard to share (export) PGN.
Click on Retrieve Position to import PGN from your device. Alternatively, if you have the game on Clipboard, you can click Clipboard and then choose to paste the game from Clipboard.


Stafford Gambit Accepted - Qe2 - What to do?

Rats. I thought I had a 5. Qe2 somewhere... Crap, that colllection of Stafford  games was on the stolen laptop.
...Bf5 was a suggestion earlier, right? Then if d3 kicks you back to c5, and d4 hits you again, you can drop back to e6 without blocking the bishop, or go in for ...Ne4 f3 Qh4+ Qf2 (what a mess) .


The Start here section of the SCID official webpage provides a lot of different links explaining the functionalities of the program, what can you do with it and what can you do to help back, among many others.

SCID provides a free alternative to commercial software, compatible with the standard .png format but with an own format .si4 said to be one of the key points when it comes to the speed of SCID analizing and mantaining a huge database.

It is compatible with very powerful engines like Rybka or the famous Stockfish used for everyone from an amateur to top GMs.

This is just an intro to all the info that you can find in the official page. The FAQ section is also very useful if you're approaching SCID for the first time.


Looking for a repertoire book on the Spanish with 5.d3 (4.d3 vs the Berlin)?

The Ruy Lopez: Move by Move by Neil McDonald contains both a d3- and a main line repertoire against the Ruy Lopez.


What are the actions one can do against chess.com players who stop moving when they are in an objectively losing position and refuse to resign?

Assuming you also have plenty of time on your clock, make a break: have a drink, or check your mail, or pay a visit to the bathroom, or grab a book (even if it's an openings book, it doesn't count at cheating in that position ;) ), or go verify if your baby hasn't hurt herself with that knife she was trying to grab when you were too busy calculating your Bxh6! sacrifice to stop her. Meanwhile, check every five minutes that the opponent hasn't played (the worst trick would be if he plays a meaningless move at some point and ends up winning on time). After your well-deserved 20' pause, collect your point, block this undelicate opponent to make sure you never play against him anymore, and look for another partner. You will win the next game as well thanks to your fresh mind after the 20' break.

In case you're a real chess lover who doesn't care about his virtual Elo rating, and really just want to start a new game as soon as possible, the alternative is to resign yourself. I almost never do that because I do care about my little rating points (vanitas vanitatum, omnia vanitas) and because the pueril opponent might believe he has been smart when he gets gifted that pseudo-win, which might even encourage him to continue his misbehavour. But objectively, we shouldn't care at all what the abusing, unfair player is thinking - It's not our job to educate him, and we don't have the means to do it anyway.


Is ECO still the best reference for all chess openings?

There does not seem to be a consensus on this, but here is a relevant discussion:

https://www.chess.com/forum/view/chess-equipment/chess-opening-reference-books?page=1

For printed opening material (as you requested) I prefer ECO with Chess Informant updates for new opening ideas and analysis:
http://www.chessinformant.org/about-chess-informant/


2.f4 is a poor move, just like 1.Nh3 was. 1.Nh3 puts White at roughly -0.50; then, after 1...Nh6 White comes back to around 0.3. If Carlsen had played 2.d4, like you said, he would have maintained this evaluation. Instead, 2.f4 brings things down to -0.4ish.

A reason behind 2.f4 is to bring the knight back to f2, but it's still a bad move. As I mentioned in the previous question on this game, Carlsen was clearly just having fun in an online rapid game. There was no deep strategy involved. If he wanted to play some deceptive variation with the sole intention of winning, you would have seen something far more impressive than this from the world champion.

If you want to analyze Carlsen's games in order to learn from them, please take a look at ones he's played in serious super-GM tournaments. Trying to glean knowledge from an online game in the PRO league isn't worthwhile (especially when 1.Nh3 is the first move).


Is holding the opponent's captured pieces legal or allowed?

The first thing to note is that even if the opponent is deliberately hiding your captured queen (or any other piece you might want to promote to) there is no excuse for using some substitute because the rules allow for a simple solution: stop the clock, call the arbiter and ask for the piece you require. It is part of the arbiter's job to do this.
Holding a captured piece or pawn is perfectly legal as long as it does not distract or disturb the opponent. Some players like to hold a captured piece between thumb and finger and spin it.
Gelfand is famous for doing this. He always does it under the table so that the opponent doesn't see it and so cannot be disturbed by it. If your opponent does this where you can see it and the movement disturbs you then you are within your rights to call the arbiter and complain.


How is this a “draw by three-fold repetition”?

FIDE rules, 5.1:

  d. The game may be drawn if any identical position is about to appear or has appeared on the chessboard at least three times. (See Article 9.2)

FIDE rules, 9.2:

  The  game  is  drawn  upon  a  correct  claim  by  the  player  having  the  move,  when  the  same  position, for at least the third time (not necessarily by a repetition of moves):
  ...

The emphasis is mine, and that's what happened here. The position was repeated 3 times, but the moves weren't. However,  that is still a draw.


How is this checkmate ... or does chess.com have a bug?

Obviously, this is not a checkmate. Something else must have happened.
Here is what I could imagine:

Maybe you have lost on time, and not by checkmate
Maybe this is the position before White's last move (Qh6# or Qxh5#), which was played a mili-second before the computer claimed victory - so that the mating position wouldn't have been visible on your screen for long enough for you to notice.
Maybe (but unlikely) there is some bug in the software. Possibly the software 'played' Qh4xh5# but somehow sent Qh4-g5 to the virtual board for unknown reason.


Why does the engine tell me to sacrifice a queen for bishop after a failed Scholar's mate?

It's basically a trade. After you take the bishop, if the opponent takes your queen with the knight, then your bishop is no longer blocked by the knight and you can take their queen too. The advantage here is that after the trade, the opponent's king will have to take your bishop, and thus can no longer castle.


Has AI changed opening theory, and if so, how?

AI has changed theory by allowing theoreticians to grind through variations tirelessly.  Due to the tactical prowess of even common computer programs it's pretty easy to ensure that variations contain no unexpected barbs.


Which openings are playable at (pre-)FM level - IM level?

Opening advantages are fine things. Maybe you can even find an opening that lends itself to your 'style' of play. But what value does any of this have? Really?

Firstly, to become a master you must be able to play all sorts of positions well. Playing a limited set of openings directly contradicts the goal of practicing a wide variety of positions. Or does it? Really? You see, we're not masters yet, so our games are likely to be unpredictable and messy.

What this means is that until your middlegame and endgame skill is at the master level your opening choices matter very little. Think of it the other way; if you're playing a master and you've somehow managed an opening advantage the master will just dig in and outplay you in the middlegame or endgame. To become a master, you will also need to acquire these skills - so you'd better find ways to get opening-disadvantages as much as possible!

I guest the real point is that even heavily unbalanced positions often have excellent drawing chances for the disadvantaged player. A master will be able to make use of these to greatly reduce the chances of a loss. The difference in opening choices in this sense comes down to the master's goals for a particular game. Would they be happy with a draw? How much do they want to risk pushing for a win if complications might also favour their opponent? Perhaps they check a database and find that their opponent only wins 2% of games that feature a Queen-side attack when the dark-square Bishop is exchanged - interesting, maybe it's worth trying a Trompovsky as White and pushing c4 early?

This line of reasoning is just beyond being useful for non-master players.

So now we see what Kasparov means when he says that all openings are playable. In almost all cases openings are simply irrelevant. Masters might try to expose each other's weaknesses with them but even at the highest level, it is middlegame and endgame skills that decide games.


Firstly, FEN notation is used to describe a board state or permutation, not a family of board states or permutations.

What you are talking about, is a way to index board positions based on your criteria. i.e. Rook vs Knight end games or such

This can be done by most database software (Fritz, Chessbase). This is done by searching games in the database, and pulling them out based on the board positions.

For example, if I want to get a bunch of rook vs knight end games, I can search for all FEN strings that contain only K,k,p,P,r,R,n,N. Basically, positions that contain pawns, knights, rooks and kings.

As for egtb, the format are stored using bit bases and the positions are assigned to a unique index. I would assume this is how Chess Position Trainer stores its FEN strings in order to determine transpositions.


What are the fastest horizontal checkmates for both castlings?

I know this thread is old, but here is my improvement to kingside castling-8.0 moves. Black even has to do one useless waiting move (Ng4).
[FEN ""]
1. e3 e5 2. Ke2 c5 3. Kd3 Bd6 4. Ke4 Nh6 5. Kd5 Ng4 6. Kxd6 Qf6+ 7. Kc7 Qb6+ 8. Kxc8 O-O#

Queenside castling can be proven to be impossible in 8.0.


Yes, you can, as long as the king doesn't pass through or end up on an attacked square.

From FIDE Laws of Chess:

  The right to castle has been lost:

  if the king has already moved, or
  with a rook that has already moved.

  Castling is prevented temporarily:

  if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or
  if there is any piece between the king and the rook with which castling is to be effected.


How should I play the Old Benoni Defense as both White and Black?

As white I have had a pretty easy time following up with the moves c4 - Nc3 - e4 - f4. Black will usually play e6 and exd5 - respond with cxd5. White ends up with a ton of space in the center. Look up the Taimanov variation in particular.

Basically I got this from MCO15 - the author mentions that many players use a different move order to reach the Benoni just to avoid this setup (they wait for white to play Nf3 blocking the f pawn).


pgnscid does not have a replacement. Instead, it is expected that you import the pgn file within a SCID database.


Is it possible to play 1 minute bullet with no increment over the board?

I've played one minute, no increment, over-the-board chess, it definitely can be done.  My experience (at least with the opponents I've played with...) has been that it's almost always turned into a huge time scramble with lots of knocked-over pieces, and I can tell you that a substantial fraction of the games I've played at this time control (maybe 20% or so - just a guess off the top of my head) have ended with one player or another making an illegal move - often because they didn't notice that they were in check, or because they tried to move a pinned piece or something and ended up putting themselves in check.  Depending on who you are playing with (and your own habits in this regard), I'd personally recommend playing like this only with a clock that you don't really care much about - many of the opponents I've played at this time control have been really rough on the clock...


How many chess clubs are there in the world?

I would imagine that the number of chess clubs remain relatively constant. From my small sample size of exposure, I have not witnessed a single chess club die out but have seen a few born. Chess is certainly not decreasing in popularity, so I don't see a reason why there would be a decrease in the number of chess clubs.


How to think this end game puzzle and play this position

As you rightly point out Kc4 is forced for white and then whichever king has to move first loses.
It is worth quickly checking if white can abandon the d5 pawn and go for the a5 with the intention of queening the a4 pawn. You do this by counting to see who queens first.
For white it goes Kb5, Kxa5, Kb4 (to threaten the c pawn), a5, a6, a7, a8=Q - 7 moves.
For black it goes Kxd5, c4, Kd4, c3, c2, c1=Q - 6 moves and black will win the white queen after checking on the b and a files.
White can avoid this by going Kb6 instead of Kb4 but then black can miss out the move Kd4 and queen two moves before white instead of just one. Again lost for white. So the kings are locked in place.
We can see that here:
[fen "8/5pp1/3k3p/p1pP4/P7/3K1P2/6PP/8 w - - 0 1"]

1. Kc4 h5 2. Kb5 Kxd5 3. Kxa5 c4 4. Kb4 (4. Kb6 c3 5. a5 c2 6. a6 c1=Q 7. a7 Qb2+) 4...Kd4 5. a5 c3 6. a6 c2 7. a7 c1=Q 8. a8=Q Qb2+ 9. Ka4 Qa1+ 10. Kb4 Qxa8

Then it becomes a case of counting "reserve moves". Basically the number of reserve moves each side has in this position is the number pawn moves before losing something. Black has two problems here. First they have to move first and second the symmetry in the position suggests that the number of reserve moves for each side is the same.
Obviously, unless you have a tactical possibility, then you only ever want to move a pawn one square forward and never two. That would be a blunder and just lose a precious reserve move. Also, if you can move an opposed pawn past the halfway line between your pawn and your opponent's pawn you can maybe gain a move / deprive your opponent of a move.
Checking that is relatively easy. Here is what it could look like:
[fen "8/5pp1/3k3p/p1pP4/P7/3K1P2/6PP/8 w - - 0 1"]

1. Kc4 h5 2. f4 g6 3. g3 f6 4.h3 g5 5. f5 g4 6. h4

and black, as predicted, has run out of reserve moves first and so loses.


This is really really wide and there are entire books written on this topic. But a few words of comment from me:

ad 1: First of all, it's not necessarily Petrov's anymore. 3. ... - Nc6 transposes into Four Knight's / Scotch for example (yeah, entire books here as well). 3. ... - Bb4 is a bit more "Petrov's" move. Then something like 4. Ne5 - 0-0 5. Be2 - Re8 6. Nd3 - Bc3 7. dc3 - Ne4 and we have a kind of Ruy Lopez with a tempo more.

ad 2: a) I think there's no point in typing here whole lines of theory. In this variation, IMHO, you need to prepare c4 sooner or later. Otherwise it's unlikely to get advantage. The second line you mentioned 5. Nc3 is about getting ahead in development. The cost of it isn't that high. It's doubled c-pawns which are not an issue as long as there are pieces on board. (Fortunately, black has d-pawn. With e-pawn those structures might be problematic when it comes to endgames. So a tip from this sentence might be "rather don't exchange on e5 letting black capture with d-pawn"). Usually White is able to launch some attack on black's kingside castle.

ad 3: I have never played those lines in my life. Sorry.

Anyway, Petrov's defense is rather logical and quite easy to play. You don't even have to know theory very well to get slightly advantageous position by thinking at the table. As I mentioned before, you should narrow your question a bit. To get a really valuable answer we would have to rewrite whole books here :)


What is the worst opening move, and why?

1. f3 is almost certainly the single worst move.  It irrevocably weakens white's king position without doing anything useful.

Other moves like 1. b3 and 1. g3 prepare to develop a bishop, so they're not so bad.  1. c3 doesn't do too much for white, but it also doesn't hurt him.

1. a4 and 1. h4 both ignore the center, but they do help develop the rooks, and there are positions where 1. a4/h4 can be useful (especially when the kings have castled on opposite sides of the board.


A list of all authentic games that have happened so far

I don't think there is any such database that only gives your names and results. But there are some mega databases you can download and script to anything that you want.

http://shop.chessbase.com/en/products/mega_database_2015
http://www.top-5000.nl/pgn.htm
365chess.com
http://ficsgames.org
net-chess.com (where you can download correspondence games)

and others.

All you have to do is simply take a PGN file and script off the names of the players

[Date "1992.11.04"]
[Round "29"]
[White "Fischer, Robert J."]
[Black "Spassky, Boris V."]
[Result "1/2-1/2"]

In this example, you'll just need to look for "White", "Black" and "Result". This is not a very hard scripting problem, you can even do it with unix commands. If you don't know how to write a script, please consult online documentation or post a question to stackoverflow.com.


Chessbase 13 How to install UCI Engine when menu item is missing?

At the end of the line Remove Kibitzer, there is "UCI" written in red.  Click on that.


Evaluating Elo rating on a per move basis

Is there another tool/app that can evaluate the strength of individual moves during each and every game, that would tell me the "strength" of the move?

To be able to evaluate the strength of individual moves, one needs to estimate the difficulty level of the position. This estimation rests on two ingredients: the ability to evaluate the position (almost) perfectly, and a sample of responses for that position from a pool of players with different strength. This is thus an empirical question.

For tactical training, there are straightforward implementations, such as this one:

http://chesstempo.com/user-guide/en/tacticRatingSystem.html

You can add to the accuracy of a solution a time element:

http://chess.emrald.net/time.php

For any kind of position, I believe it's still an open problem.

A related question is the optimality of play. To that effect, Guid & Bratko did an interesting study:

  The basis for their evaluation was the difference between the position values resulting from the moves played by the human chess player and the moves chosen as best by the chess program Crafty. They compared the average number of errors in the player's game. Opening moves were excluded, in an attempt to negate the progress in chess opening theory.

http://en.wikipedia.org/wiki/Comparison_of_top_chess_players_throughout_history

But such study cannot estimate the strength of a player as requested by the querent. It can only evaluate optimality of play, and order players according to this evaluation. This does not give ELO or complexity of any given move.


I have been looking at this with a fairly strong computer for about 15 minutes (and the judgment of having been a Master for 30+ years and forcing in plausible lines), and I am convinced that this is a positional draw.

White is obviously worse per the computer eval, but he can keep the position exactly as it is by either moving his K from e2 to d3 and back (sometimes f1 if there is a threat to take on g2), or his Rd4 back and forth to d1 if black moves the Re5 away so e4 is not hanging. So, that leaves only to look at what can black do.

You have to look at black's pawn breaks. Clearly, b5 is out as cb actually leaves white better. d5 just loses. f5, which would be the standard try, is never any good because after ef and the bishop trade on f3, that will leave a monster N to go to d5, and that will also keep black tied to the weak pawn on b6. That only leaves the attempt to double rooks on the g-file, and sacrifice on g2, but it is already defended twice, and can even be over-protected with Kf1 if it looks like it might work for black.

Lastly, on top of b6 being weak if f5 gets played, h4 also becomes an immediate target along the fourth rank.

My opinion is that if black tries to win, especially with f5, he is probably going to be worse, and it will be he, who is fighting for the draw. Sorry, I just do not think that there is a way to crack that nut. Try too hard, and you might break an egg though. :)


For how long can lone bishop stop king, knight and pawn?

The reason why endgames are difficult, despite there being only a few pieces left on the board, is that many positions can only be evaluated by accurate calculation rather than by appealing to any rule. Rueben Fine in Basic Chess Endings says that KNPP vs KB "is in general a fairly simple win. The exceptions come only with a blockade" He then analyses seven examples of marginal cases. One very surprising example is that doubled pawns always win, a rare case of a universal rule. But even then, some accurate moves have to be found.

But some general advice is possible. For the superior side. Make active use of your King. Send him on ahead of the pawns and then escort them through. For the defender, try to keep your bishop on the longer of the two diagonals that control a crucial square. That will give a better chance of having waiting moves available. But always calculate.


These tricks work much better in bullet, where flagging is probably 50% of the game, than in blitz.

The obvious one is to reply to the start of a fianchetto by threatening the square the bishop is about to move to in case it was pre-moved. e.g. reply to g3 with Bh3. Of course if your opponent didn't pre-move and your bishop is unprotected then you lose a piece but you should only do this when your opponent is playing some opening with minimal contact and with automatic moves like for instance the Kings Indian Attack with white.


In the context of game theory, perfect play involves playing truly optimal moves.  Specifically, if the game state is a (theoretical) win for the player to move, perfect play would be a move that both preserves that state (eg keeps the game a winning state) and minimizes the number of moves remaining until victory.  If the game state is a draw, perfect play preserves the draw.  If the game state is a loss, perfect play cannot improve the theoretical outcome, but instead maximizes the number of moves until defeat.
Perfect play is, by definition, known for solved games like Tic-Tac-Toe.  Chess is not yet solved, so in most board positions, perfect play is not known.  For some situations, for example positions with 7 or fewer total pieces on the board, we have endgame tablebases which have perfect play recorded.  Also, for positions with forced checkmate in sufficiently few moves, engines can calculate perfect play on-the-fly by simply looking at all possible moves and responses and choosing one that gives checkmate the fastest.  Perfect play is not (yet) known for chess openings.  If chess were solved and perfect play were widely known, then it is possible competitive chess may die.
There can be multiple perfect moves for a given board position.  For example, if there are two different moves that immediately checkmate the opponent, both are perfect.  Playing around with endgame tablebases, it is fairly common to find positions where multiple moves lead to checkmate in (say) 18 moves.  If the game is a theoretical draw, often many moves preserve the draw.  All of these moves are perfect from a game-theory perspective, though some may give better practical chances than others.


Is it beneficial to play blindfolded chess?

In my opinion

I cannot speak to the health benefits or drawbacks of playing blindfold chess (which I find to be, in my opinion, baseless).

What I can say is from experience. I have attempted playing blindfold chess when I was not a very strong player and found it challenging and not worthwhile. However, as my chess progressed I found playing blindfold to be a lot easier, and was even recently able to play a game to the 62nd move where I checkmated my friend. It took 90 minutes.

My main point is that that blindfold chess more than likely does not affect your chess ability. It is your chess ability that affects your blindfold chess.

Here is are some conclusions from an in depth study

Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2972788/

In their review of the literature, Hearst and Knott document a number of notable conclusions that may surprise chess players and non-chess players alike:

The general memory of chess masters, including those able to play many blindfold games simultaneously, is no better than that of the average person.
Highly skilled players can form long-term memories of full-board chess positions within seconds of viewing them.
High level chess skill (not just blindfold chess) requires a recognition-action repertoire of some 50,000 to 100,000 features of chess positions and associated responses.
Some of the strongest masters find the actual sight of a chess position to be more distracting than helpful when thinking ahead during a game.
Practicing blindfold chess improves sighted chess skill.
Some of the strongest blindfold chess masters claim that the strength of their blindfold play is similar to that of their sighted play.

Bonus material

In case you really want to read up on the subject: http://www.wjh.harvard.edu/~cfc/Chabris1999d.pdf


How to best respond to an early black Qa5 in the Smith-Morra gambit?

I don't see why you can't just ignore the Queen on a5 for now and play Nf3, followed by Bc4 and 0-0. Then, there is no pin on the c3 pawn anymore and he must take on c3, after which you retake with Nxc3 and you're back into a normal Morra gambit position with his queen oddly placed on a5. If he doesn't take on c3, then you just take back on d4 with a large center. You are not forced to stay in Morra gambit territory forever if there's a better line you can play.


It is a matter of choice
Many grandmasters (e.g. world champion Viswanathan Anand) have consistently played 1.c4 e5 with Black. Others favour the KID or other defenses : Hedgehog (with b6), symmetrical English (1.c4 c5), Pseudo-Nimzo (with Nf6 and e6), Pseudo-Grünfeld (with Nf6 and d5), Réti (with e6 and d5) or Slav-like (with c6 and d5) defenses...
There is no definitive hierarchy between all those schemes. You may well prefer 1...e5 and you won't be the only one (this is actually my favorite retort nowadays) but there is no objective reason to think that this choice should be "slightly better" than other reasonable defenses. What suits us doesn't suit everybody.
The case with the KID
The King's Indian Defense has many pluses and minuses: lack of space, ressources for counterplay, long theoretical lines... But one thing that makes it attractive for many players with Black is that the KID is an holistic opening solution for everything but 1.e4 : if you wanna play the KID, you can go for it whether I start with 1.d4, 1.c4, 1.Nf3, even 1.g3 or 1.b3, and there is little I can do to stop you.
As a consequence players who are confident in their KID repertoire against 1.d4 have little incentive to switch to different schemes to meet 1.c4, and prefer to transpose with 1...Nf6 and 2...g6 rather than work on the theory of the pure English 1.c4 e5.


In Swiss tournaments, is it common to play weaker players when playing White?

Your 1% chance calculation is wrong, because "observations" are not independent from each other within a single tournament. When you play one round as White, you are very likely to play the following one as Black. Also, after a win, you are very likely to face a stronger player in the next round. So your tournament could go something like this.

WHITE, weak opponent. WIN

BLACK, strong opponent. LOSE

WHITE, weak opponent. WIN

... (you get the idea)

This means that if, in 3 consecutive tournaments, you get to play a weak opponent as White (let's say that, by ranking, you are about 100th in a pool of 200 players), you can easily get pairings such as those you are showing (with a 1 in 8 chance, and also a 1 in 8 chance of getting the exact opposite)


well my 2 comments got upvoted, so who knows, maybe i can turn this into an answer.
(Note: I wasn't really into chess or chess960 at the time I read the book (except that I played a few tournaments as a kid), so wow this was a little nostalgic. When I did get more into chess/chess960, I read about the silman position. That's about it.)
jeremy silman talked about the position in these 2 links in the description here. unfortunately, they're both dead. let's see if i can dig up web archive. oh yeah here we go
https://www.jeremysilman.com/book-review/creating-the-harry-pottter-chess-position/
(also http://web.archive.org/web/20170801000000*/jeremysilman.com/shop/pc/Creating-the-Harry-Potter-Chess-Position-87p3692.htm and http://web.archive.org/web/20111201000000*/jeremysilman.com/movies_tv_js/harry_potter.html)

aaaand of course there's agadmator: Ron Weasley Sacrifices Himself for the Team

anyway, let's see if the game in the movie satisfies the conditions

White starts with 1. e4

Yes. Ron does Scandinavian defense.

The white queen takes both black knights

Well, no, just Ron. But the other knight doesn't really do anything, so I don't see why there couldn't have been a position where Harry, Ron and Hermione have lost their other knight.

Wait, maybe, there was AN EARLY UNDERPROMOTION.

The second black knight (Ron) sacrificed himself to the white queen in order for a bishop (Harry) to travel 3 spaces to the left for mate

Yes, assuming you don't count the intermediate move of capturing the queen (the movie didn't seem to count this!)

The first black knight was taken for a trade for a black rook (Hermione) to take a white bishop

see (2). Also, Hermione doesn't seem to have moved much. But she does have control of the f-file.

Both the bishop and rook (Harry and Hermione) were in danger twice

Harry: Yes. Immediately before Ron checks king at end, Harry, as the dark square black bishop, is in line of sight of white queen.

Hermione: Seems possible. There's no indication for Hermione in danger, but I don't see why there can't be a game like this.

The second black knight (Ron) took the most white pieces

When playing a game, I don't know of anything where people keep track of which piece captured the most pieces. This sounds something like determining which piece is like the 'MVP', like the online pokemon TCG or csgo. I don't think this is a chess thing. But I guess it seems plausible.

The same black bishop (Harry) went 4 spaces to the right in the opening

Harry as the dark square black bishop could've done Bb4, like in Nimzo-Indian Defence, but Nimzo-Indian Defence is a response to 1.d4 and not 1.e4. Perhaps there's some variation of Scandinavian that involves Bb4. According to this, there's something called 'Scandinavian, Anderssen counter-attack orthodox attack' that goes

e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 e5 5. dxe5 Bb4 6. Bd2 Nc6 7. Nf3

[White "Some 1.e4 player"]
[Black "Some Scandinavian player"]
[Result ""]
[FEN ""]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 e5 5. dxe5 Bb4 6. Bd2 Nc6 7. Nf3

Also, notice that before capturing the queen, Harry is along the same diagonal of b4 and Harry's starting square (f8).

But actually 4 spaces to the right is a pretty common thing I think like Ruy Lopez.

Update: Does Magnus Carlsen Remember the Position in Harry Potter Movie?
Here, Carlsen claims that the moves Qc3 and Nc6 were played. Not sure either of those moves were played, but in the silman position Qxd3 (not Qd3 and not Qc3) and Nh3 (not Nh6) were played.


Why did the Berlin Defense of the Ruy Lopez disappear from the play of World Champions before Kramnik revived it?

The reason, as far as I know, it is because it is drawish. GMs look for opens that are either heavily imbalanced or uncertain, like the sicilian or the scotch, or quiet oppenings that allow positional manuevering, like the Caro-Kann. Drawish lines are used by GMs solely when they are required.
Another reason is that the Berlin wasn't almost played at all in GM level. Kasparov didn't have such a deep knowlege of the opening, unlike Kramnik. Openings decide games in World Championships.


Creating program for finding top players with respect to elo and age

Are there some resources I can take some historical databases from?

You need two sets of data:

Rating data for the players going back as far as possible in time
Date of birth data for the players

There are two very good sources which will help a lot with ratings and help a little with dates of birth. The bad news regarding dates of birth is that in the modern age full dates of birth are generally not published because of security risks. If you are going to try and steal somebody's identity with a view to stealing their money then full date of birth is one of the key components.

FIDE published about 19 years of rating data which is available for download. Olimpbase have data available for download going back another 30 years.

The Olimpbase data has both ratings and full date of birth data but is very "dirty". You will need to "clean" it before you can use it to remove duplicate data and resolve players with the same name, the same player with different names (women players who got married, perhaps more than once, and changed their names and also just typos in the data).

The FIDE data is also a bit "dirty" in the early years but gets cleaner in later years. You will have much less data to "clean". It has year of birth only so getting the full date of birth for players will involve a lot more work digging through resources like Wikipedia.

  I think it needs (relatively) easy programming or not so much?

A major task will be extracting the data you need from your data sources. This will be a massive task. I would suggest you design a relational database for your needs and populate it from your data sources after first cleaning the data. Once this is done answering the questions you want is a relatively straightforward matter of writing some simple database queries and running them.


What are some helpful chess tactics training websites?

Chesstempo.com is the one I use. It's pretty excellent. I'd like to hear if there's a better one, though.


Can Black successfully finish this opening?

I actually used to play the Scandinavian a lot in blitz a couple of years ago, then got bored with my line and never used it again. The starting position in your diagram is actually one of the typical positions one reaches in this opening, although with slight variations, (like same position with e6, c6 already played etc.)

Since you said you've been working on e6 on your own, I figured I should spend time figuring out other lines. I have a lot of experience in Catalan like openings, so the main line I am going to suggest is slightly inspired by that.

Main line that I suggest is ...g6. For a couple of reasons:

This position can be transposed into a semi-Catalan because black has kept all the pawns on the 7th rank still, which allows for a very robust-slow type of development with a passive activation of pieces. Hence the fianchetto.
Although e6 may look very natural, and does cover a number of things, it doesn't create any prospect for the bishop as it will have to stay on e7 and not contribute much. Whereas a fianchetto'ed bishop on g7, for one thing avoids any exchange any time soon, and very importantly covers a crucial diagonal in the position, because as long as there's pressure on d4, c4 cannot be played easily by white, and queen may be temporarily restrained to defending d4 (e.g. in quick Qf3 lines d4 becomes very vulnerable) and we keep an eye on b2. Finally a possible expansion with c5 or e5 becomes plausible with Bg7.
Another strong element in our position which we should definitely leverage, is the queen, being already very active and not necessarily too exposed. Its main use in this position should be defensive (and of course space control) until black has securely finished development. So in the lines I will suggest, the queen will often end up defending here and there, but why not? After all the point is to make this position work in a sensible way.

Let's see some lines:

[Title "..g6 2.Re1"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Re1 Bg7 3.Bf4 O-O 4.c3 Nd7 5.b4 Qd5 6.Bxc7 Rfc8 7.Bf4 Nf6 8.f3 a5

With a very playable active position for black, if anyone's winning here, it's black. B6-g1 diagonal is very weak, the b4-c3-d4 structure is very shaky and will cost white either some pawns or loss of activity if he goes for a complete defensive plan. Black has no worries and all the pieces are active, perfect so far!

Second g6 continuation:

[Title "..g6 ...Bg5 instead of Bf4"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Re1 Bg7 3.Bg5 h6 4.Bh4 g5 5.Bg3 Nd7 6.Qe2 O-O-O

Again black ends up with a solid structure and possible attacks all around: a king-side attack on white is the most natural plan from here. But a simple plan like exchanging knights and going for a better end-game works as well since our pawn advances haven't exhausted their possibilities yet (all on 7th rank) and the queen can immediately start putting pressure on white's queen-side and gain tempo for whatever other plan we may have.

Third line with g6:

[Title "..g6 2.Qf3 very crudely by white"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Ng5 Qf5 4.Qxf5 gxf5 5.c3 e6 6.Re1 h6 7.Nf3 O-O-O

A perfectly fine endgame for black, covering both g5 and e5 squares, an open line already available to us (g-file), no real worry in the position. Again an example leveraging the queen activity for defensive purposes.

4th line: (the only real dodgy line, but manageable)

[Title "..g6 2.Qf3...Nc5 instead of Ng5"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Bg7 6.Nxc7+ Kf8 7.Be3 Bf6

Sure we lost a pawn in the process, but instead once Kg7 happens, our plan is pretty clear: Use the open files b-c for the rooks, make white lose tempo with mis-placed knight (almost trapped) on c7, gain tempo on his exposed queen, and finally we have 2 fine minor pieces on f6 and d4! Very playable.

5th line:

[Title "..g6 2.c4"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.c4 Bg7 3.Bg5 O-O 4.Re1 Re8 5.b3 Nd7

Perfect position, 0 weaknesses, completed development, everything ready to plan any further attacks.

6th and last line with g6, the toughest for black:

[Title "..g6 2.Nc5 again crudely by white"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Nc5 Qb6 3.Re1 Na6 4.Nxa6 Qxa6 5.Bf4 O-O-O 6.Qf3 Rd7 7.c3 Bg7

I spent a lot of time to find a refutation to Nc5 and Qb6 was the only one that really worked(I went through very scary lines to finally find this one, hope it was worth it). Again the final position, goes without saying, is perfect for black considering the starting point for us was "being behind in development". No weaknesses, and once we have h5 and Qb5 played, everything is ready to focus our coordination on white's king-side. (useful moves for us here: e6, Bf6, Rg8...h5 g5..).

These were all the lines for g6 continuations, and honestly I like them all and find them very playable (practical terms), yeah it's true that they don't lead to very exciting middle games but hey we started off with a Scandinavian after all!!

Second alternative I had in mind was Nd7:

[Title "..Nd7 2.Qf3 "]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... Nd7 2.Qf3 f6 3.Bd2 Qa6 4.a4 e5 5.dxe5 Nxe5 6.Qf5 Be7 7.Bc3 Ng6 8.Rfe1 O-O

No pawns lost, development completed and easily refuted white's crude Qf3 with an active plan involving f6 instead of the passive h6. May seem shaky at first but we are no tempo behind in our defense.

[Title "..Nd7 2.Re1 "]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... Nd7 2.Re1 Nf6 3.Bd2 Qf5 4.Nc5 O-O-O 5.Re5 Qg4

Very solid position, with a quick queen side castle and we've kept all our g6 and e6 ideas active and open.

[Title "..Nd7 2.b3 passive-slow option for white "]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... Nd7 2.b3 e6 3.Bb2 Be7 4.c4 O-O-O 5.Bc3 Qf5 6.Ng3 Qg6 7.Qf3 Kb8

An example of white taking it slowly and us finishing development rather straightforwardly. With loads of options still on the table.

Finally two e6 lines to finish off my reply:

[Title "..e6 2.Qf3 "]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... e6 2.Qf3 Qf5 3.Bf4 Nc6 4.Ng3 Qa5 5.c3 O-O-O 6.Be3 f6 7.Qg4 Qd5 8.Nh5 f5

Another good example showing how useful the queen is in this position when it comes to immediate defensive needs (i.e. replying to crude ideas by white)

Last line e6 again, probably the most basic continuation of them all:

[Title "..e6 2.Re1"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... e6 2.Re1 Be7 3.c3 O-O 4.Bf4 Nd7

Absolutely fine for black.
I hope you find these ideas helpful, I personally like all the outcomes resulting from g6, with a lot of options left in the position. Basically I tried to consistently show that although the starting position (you've given) looks rather worrisome for black, the active queen on a5 can still save the day whenever white gets over ambitious and plays for crude attacks, and if he doesn't then black gets to finish development and keep a perfect composure in his position. From this point on, we should just discuss the specific lines that you may find interesting, in the lines I've discussed so far.

Last note: I have no idea whether all these lines will hold against an engine or in long long correspondence chess, but then again we don't care about those formats here, the idea was to make one of the variants of Scandinavian work, an opening one doesn't play against an engine anyway! Don't hesitate asking any question that you may have.

EDIT: As pointed out by Wes, the 4th line suggested for ..g6 contained some inaccuracies, hereby I suggest some improvements:

[Title "7..Be5"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Bg7 6.Nxc7+ Kf8 7.Be3 Be5 8.Bxd4 Bxd4 9.c3 Bf6 10.a4 Kg7 11.b4 Qf5 12.Rac1 Rd7

Very active position for black, pressure on c3, rooks doubling soon, white knight in an awkward pin, queen limited to knight's defense...very playable

[Title "7..Be5 8.Rfd1 To Be Avoided by black"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Bg7 6.Nxc7+ Kf8 7.Be3 Be5 8.Rfd1 Bxc7 9.Bxd4 Bxh2+ Kf1

Here is one line to be avoided by black (Bxc7 not possible) as Kf1 can be replied after taking on h2, otherwise if Kxh2, Rxd4 Rxd4..Qe5+ wins back rook and equal position. So after Rfd1 black is kinda stuck with his pieces, maybe some h-pawn move to free up room for the other rook (so g8 square remains available for the king if needed). But all this can be avoided by playing Qb6 after Na6, a complete transposition, as follows:

[Title "5..Qb6 Queen-king combo: Saving the day"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Qb6 6.Nxc7+ Kd7 7.Qe4 Bg7 8.c3 f5 9.Qe1 Kxc7

And black is back in game, after having found the nice resource with Qb6 and Kd7 making use of the mis-placed knight. (note here Qxe7+ not possible as Rd7 wins a piece). If white exchanges queens on b6 then it's equilibrated again as c2 pawn falls:

[Title "Queen exchange line"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Qb6 6.Nxc7+ Kd7 7.Qxb6 axb6 8.Nd5 Nxc2

One last variation (there are many others of course):

[Title "8.Nd5 line for white"]
[StartFlipped "0"]
[fen "rn2kb1r/ppp1pppp/8/q7/3PN3/8/PPP2PPP/R1BQ1RK1 b kq - 0 1"]

1... g6 2.Qf3 Nc6 3.Nc5 Nxd4 4.Qxb7 Rd8 5.Na6 Qb6 6.Nxc7+ Kd7 7.Qe4 Bg7 8.Nd5 Qe6 9.Qxe6+ fxe6 10.Nc3 Nxc2 11.Rb1 e5

With the knight coming back to land on d4, very promising endgame.


I can't find it now, but I remember reading this exchange on Chessbase. A player just played ...e6 on one move, and then ...e5 on the next, seemingly losing a tempo for no reason. It was clearly computer preparation however. An interviewer asked GM Viswanathan Anand what he thought about the moves. Anand replied that if the computer thinks it's fine, then it's fine. Instead you have to analyze the lines afterwards to see why it's fine.
In other words: these days computers are so strong that their judgement trumps human judgement, including those made by world champion-caliber players.
Now the fact is that computers don't like the Traxler, even at high depth. It was played in the TCEC S17 superfinal between Leela and Stockfish. Here's the first game, and here's the reverse. Note:

These engines are playing on super hardware and achieve speeds and depths that would take very long for ordinary machines. When Leela played her fifth move, she was at depth 22/62. When Stockfish played its fifth move, it was at depth 43/62.
Both finalists thought 5.Bxf7+ is the best move.
Both finalists evaluated the position after 5.Bxf7+ as +1.5 for White (more precisely, Stockfish gave +1.5 for White; Leela thought White had a 60% chance to win).
Comparatively, in the starting position, White has roughly a +0.5 advantage.
There is some fluctuation in engine eval, so e.g. if Stockfish thinks a move that is +0.1 pawns better than the next-best move, the next-best move might still be playable. However, +1 is a pretty large gap.

Therefore the only conclusion here is that the human masters are wrong. The Traxler is objectively dubious at best. Playing this can work against humans because humans cannot find a string of "only moves" in a row to hold a position, plus it's psychologically difficult to defend against a strong attack for a long time. That's why humans - even top-level humans- often crack under pressure. The Traxler also offers plenty of opportunities for both sides, which is great if you want to play for a win and/or you think you are better than your opponent. But if you play the Traxler as Black in correspondence chess, you are asking for trouble. Maybe 32-piece tablebases will show that your position isn't lost, but you would have to fight hard for equality.
Finally I'll add that it's misleading to say the Traxler is well-regarded by masters:

Wikipedia's article on the Two Knights includes this quote: "No grandmasters have regularly adopted the Wilkes-Barre as Black, but Alexander Beliavsky and Alexei Shirov have played it occasionally even in top competition"
Chess Openings Explorer gives by far the most common response to 4.Ng5 as 4...d5 (which is also the main line of the Two Knights).

I'd call the Traxler playable in human games, but only as an occasional weapon.


Can a tournament director nullify a game in progress?

In FIDE rated tournaments I remember hearing that if the starting position was set up wrong and roughly <= 6 moves were played, the game could be restarted. So if this tournament was also FIDE rated, FIDE rules take precident and restarting was fine. If this tournament was just USCF rated I'm not sure (you'd have to look up the official handbook).

I agree that some time should have elapsed for your opponent. You did nothing wrong but he did. However, you'd have to have said this during the game.


How did the Grand Prix Attack get its name?

From this page, I quote

  The Grand Prix Attack got its name from the many strong British
  players who used it on the Grand Prix Circuit in the 1980's

As Remco Gerlich said, It was used by British players on the British Grand Prix circuit. Weekend tournaments that also have a combined standings.


There are a few ways to deal with pins in general:

Break the pin. In the position you posted, a long term plan might be to play e3, Nge2 and O-O
Ignore the pin. In the position you show, if black takes on c3, he surrenders the bishop pair (specifically his better bishop) for a knight whilst giving you a semi-open b-file. But this is at the cost of a weakened pawn structure
Play prophylactically. This depends on the position though. Sometimes it is a weakening move, e.g. playing h3, O-O may allow a sacrifical attack with ...Bxh3
Put the question to the bishop. White may want to test black with a3, putting the question to the bishop of 'are you going to take or retreat?'
Play a cramped  game with Nbd2, which allows c3 if the bishop comes to b4


Why isn't the objective of chess to capture the opponent's king?

Short of tremendous blunders of moving into check, chess would be completely the same

But it wouldn't be the same. There is one case where moving a king into check would not be a blunder. That case is what we currently call stalemate. If it was legal to move a king into check, then almost all cases of what is currently stalemate would instead be a win for one side.

This would have a huge impact on the endgame. Many endgames which are currently draws would turn into wins for the side with more material (KP vs K would win regardless of opposition, for example, and many other endgames can be simplified to that) and many theoretically won but difficult endgames would be much easier to win (since KNN vs K would now win, KNN vs KP could be won by just taking the pawn.)

And this effect on the endgame would in turn have a large effect on the earlier stages of the game. It's harder to sacrifice a pawn if you know you don't have drawing chances in the event that you end up a pawn down in the endgame.

You could, of course, hack a stalemate exception into the new rules, but that would probably be even more confusing.


Not to rain on your hopes - but the problem you're looking for at first appeared in:

  Troitzky, A. (1924), 500 Endspielstudien, Verlag Kagan, Berlin

Troitzky was an impeccable note-taker when it came to chess.  This book was End Game Studies and show endgame positions with only with a few endgame moves.  It didn't show complete games.

  Unfortunately all of his notes were destroyed in the siege of Leningrad, so there is likely no record of this complete game (not even in Russian sources). (He also died of starvation during the same siege)

Please don't shoot the messenger.


There is an "eco" GitHub project available which I believe, based on the name, is based on the Encyclopedia of Chess Openings.

This project used to provide a JSON file with all openings, but now provides a set of tab-separated files with columns for ECO code, name, FEN, and moves.

To give you an idea of the format of the file, here's the entry for Ruy Lopez: Marshall, Main Line, Spassky Variation, which happens to be the longest opening in the file:

C89     Ruy Lopez: Marshall, Main Line, Spassky Variation       5rk1/5ppp/p1pbr3/1p1n3q/P2P2b1/1BPQB1P1/1P1N1P1P/R3R1K1 w - -   e2e4 e7e5 g1f3 b8c6 f1b5 a7a6 b5a4 g8f6 e1g1 f8e7 f1e1 b7b5 a4b3 e8g8 c2c3 d7d5 e4d5 f6d5 f3e5 c6e5 e1e5 c7c6 d2d4 e7d6 e5e1 d8h4 g2g3 h4h3 c1e3 c8g4 d1d3 a8e8 b1d2 e8e6 a2a4 h3h5


List possible moves for player - Haskell implementation

FEN is fine for unambiguous communication of a position (if you include castling and e.p. state too) but the internal representation should be as a board, with some kind of movement so you can efficiently check for legal moves, blocks, checks etc. Would hate to do all that with regex!
This quite a well-travelled area, and there must be much material online. You have made the choice to use Haskell here: what is the motivation for this? Are you trying to learn Haskell, or do you think it’s appropriate for certain aspects of a chess engine.
Chess is a finite directed binary graph, with each position just a node. There is certain machinery to reach that level of abstraction, but ultimately I would think a functional language like Haskell might really begin to show its worth when you have reached that conceptual level.
Depends also what you want your engine to do: find good moves, solve problems, analyse endgames, tablebases, retrograde analysis, support fairy chess. So please say more! :)


Is there software that simulates the Tri-D or 3-D chess as seen in Star Trek?

From wikipedia:

  There is software for playing Tri-D Chess; Parmen is a Windows application written by Doug Keenan and available free on his website.

Here are some of the external links for (software) Raumschach and Tri-D chess:

  http://www.pathguy.com/chess/Chess3D.htm

  http://www.cosmicchess.com/

  http://www.parmen.com/

There is a version available for Android:
https://play.google.com/store/apps/details?id=awfsoft.app.TriDChess


What are the most characteristic signatures if an opponent cheats in online game by using an engine?

There are a range of factors sites use;
Such as play style, move depth , skill level vs move skill level. Engines are emotionless and are willing to just commit.
Things such as ;

Move depth not comparable to skill level
Move Time being consistent eg 5 seconds per move (hard to demonstrate her)
Consistent string of flawless games

Move depth not comparable to skill level
I have the following of a game played recently in an club vs club tournament on Lichess. This juniors game was detected as having cheating in it. Whilst it was being played people were suspicious by the two particular moves highlight below.
This highlighted moves are something you would expect to see of players rated 2000+ and isn't a natural move to find especially for juniors. The human brain sees the rook move and discards it almost immediately as a Rook trading for a Bishop. I have reviewed the games since and found that the move list was 1 for 1 the entire time for black against StockFish 10
[White "White "]
[Black "The Suspect"]
[Event "Hyper Aggressive Sacrifices (Blitz 3|2)"]
[FEN "2krr3/ppp2ppp/2n3b1/4n3/2P3P1/P3PN1P/1P1NB3/2KR1R2 b - - 0 18"]
[StartFlipped "0"]

1... Rd3! 2. Bxd3 Nxd3+ 3. Kc2 Nf2+ 4. Kc1 Nxd1 5. Kxd1

Another Example from the same game;
[White "White"]
[Black "The Suspect"]
[Result "0-1"]
[FEN "2kr4/ppp2ppp/6b1/8/2P1P1P1/P3rB1P/1PKN1n2/3R4 w - - 0 24"]

1. Rf1 Rxf3! 2. Nxf3 Bxe4+ 3. Kc3 Rd3+ 3. Kb4 Rxf3 3. Re1 Nd3+ 0-1


Despite this post being over 2 years old, the position seems to be very interesting and caught my attention. So here are my two-cents on it:

I'm rather surprised by white's follow-up moves in that game, I just don't see what is being gained! Instead, first thought that comes to my mind is to bring the h3 bishop into the game, which in fact in the actual game is left on h3 for at least 10 moves, then moved to f1 and eventually e3-Be2 is played, but in all that the light square bishop has played no role whatsoever to justify white for being up a piece.

So let's simply focus on that and try to revive the bishop with Kf1 and Bg2. Once our bishop is in play, the trade of black's bishop for our knight will likely be in our favour as we'd still have our two pawns, and two active pieces against the single rook, whereas in the game itself, once the bishop is brought into the game, white has already lost the h2 pawn and black's pawns are already storming down the board.

Here's an annotated diagram to study Kf1-Bg2 idea:

 [title "A different approach for white: reviving the bishop"]
 [fen "N7/P3pk1p/3p2p1/r4p2/8/4b2B/4P1KP/1R6 w - - 0 34"]

 1.Kf1 Rxa7 2.Bg2 g5 {the early g-pawn push is mainly aimed at stopping white's h-pawn from advancing and attempting to undermine black's pawn chain. If black is allowed, g4 is next.} 3.Bc6 {Important move here: stops the Ra4 - Rf4+ - Rg4 maneuver, and leaves g2 as Luft for the king thus freeing the rook from the first row, more active prospects compared to g2, and temporarily untouchable on c6 as Ra6 can be answered by Be8+ and Nc7, all while maintaining control over the important long diagonal. } g4 (3...e6 4.Rb7+ Rxb7 5.Bxb7 {and if anything the draw is well in hand, as we've kept the knight next to the opposite color bishop situation.})  4.Nb6 {hard to find an immediate plan for black} Bd4 {prophylactic vs Nd5} (4...Bxb6 5.Rxb6 {and unlike the actual game we still have the h-pawn, our bishop is in play, and our rook in time to go behind the pawns} h5 6.Kf2 h4 7.Rb8 Ra3 8.Bd7 e6 9.Rh8 {forcing h3 with all the pawns on light squares, then we just have to stop f4 and black cannot make progress.} h3 10.Rh6 f4 11.Kg1 {side-stepping g3 with check, as that would probably be losing on the spot} Ra1+ 12.Kf2 Rh1 13.Bxe6+ Kg7 14.Rh4 Rxh2+ 15.Kg1 Rxe2 16.Bxg4 h2+ 17.Kh1 Rf2 18.Rxh2 {it's worth exploring some of these lines as they're very sharp and concrete therefore highly non-trivial.}) 5.Nd5 e6 6.Nf4 Rc7 7.Ba4 {Even Rb7 looks sufficient for a draw, but requires more calculation to make sure.} d5 8.h3 {if Be3, Ng2 works which is lucky. As for the rest: we've brought all pieces into play, pinned most black pawns to light squares, and managed to trade our h pawn, and big prospects of holding this position, and even winning it if black goes wrong.}

So in summary, it seems that by bringing the bishop into play immediately, we've managed to muster up an actual defense against the pawn storm, and even create active play, thus in fact making a case for being a piece up! This seems to be far more playable than the version of the endgame that transpired in the actual game.


About how to respond to this atypical black defense in the Ruy Lopez

3... d5 is not listed here so it is a safe bet there's a problem.

It looks like an overreach, with both Black pawns being vulnerable.

I'd go for a pawn steal.

[FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bb5 d5
4.Nxe5 a6 5.Bxc6+ bxc6 6.Qe2 {White has better development, better pawns, and a free pawn.}


I lost a game without making tactical mistakes; how can I avoid this happening in the future?

In this case, the answer is "gain familiarity with the standard strategical themes of the chosen opening".

Black's #1 issue in the Queen's Gambit Declined is what to do with his light-squared bishop, which if ignored can easily get stuck behind the e6 pawn and often a c6 pawn. The two standard ways to free it are

Play ...e5 to allow the bishop to move along the c8-h3 diagonal
Play ...b6 and ...c5 and place the bishop on b7

You kind of got halfway through plan #2, but once White got c5 in, your bishop had no future.

Concentrate on freeing your light-squared bishop the next time you play the Queen's Gambit Declined and you'll be much less likely to get ground down like this. This takes priority over moves like 11...Nf6 (which you just moved back two moves later anyway) and 12...Re8.


Why is, according to Stockfish (depth = 28), a4 the best move here for White?

1. a4 allows White to place his knight on the c4-square without having to worry about ...b5 kicking it away because that would be too weakening for Black, because it would make the a-pawn backwards on an open file.

1. a4 also gains space and opens the possibility of a5-a6 to soften the Black queenside for the g2-bishop. If black stops this with ...a6 or ...a5, then Black will have a hole on b6.

A knight on c4 would allow white to move his bishop to f4 to attack the black queen. If Black responds ...e5, this creates a permanent weakness on d6, and White can put his knight there. ...e5 also blocks Black's bishop. The knight on c4 also takes away many squares from the black queen, so if Black does not want to weaken with ...e5, the black queen will have to go to an inactive square.


Tools for helping to learn openings by heart

Two well-known programs that are meant specifically to aid in the memorization of opening variations are

Chess Position Trainer
Chess Openings Wizard (formerly Bookup)

Both programs are designed to recognize and handle transpositions seamlessly, and they allow a player to drill all the positions that are part of any repertoires that he or she inputs.


Is there a chess engine that does NOT use brute-force search?

There were attempts back in the 1980s to write chess engines with knowledge bases that would pick candidate moves like humans, but they were unsuccessful. The problem is that human pattern matching is difficult to put into words, so creating the rules for the knowledge base was extremely difficult.

Training a neural network to pick candidate moves seems like a promising line of research. Here and here might be two pertinent papers. (FWIW, It is not my field of Comp Sci)


Are gambits a good way to improve tactical awareness (for strong amateurs)?

Sure! Playing a highly tactical position that you aren't used to can help you train your tactics, but there are plenty of non-gambit alternatives that are also rich in tactics (think for instance of most lines in the Sicilian defense)


Why is the King's Gambit not played often?

One of the more common lines for the King's Gambit is accepting, followed by 3. Nf3.  That is, 1. e4 e5  2. f4 exf4 3. Nf3.  After this, black can follow with 3... d6,
the so called Fischer defense.  Fischer was extremely confident that this was a bad position for white.  He wrote an entire article about this line, and famously said, "In my opinion the King's Gambit is busted. It loses by force."  On top of this he added, "Of course White can always play differently, in which case he merely loses differently."

I am not sure about other lines, but likely top grandmasters have analyzed them, and come to similar conclusions that white's position is not a good one.

Remark: Interestingly Fischer himself played the gambit a few times with great success, but he opened 3. Bc4.


Can watching grandmasters' games improve my chess 'thinking'?

Chess "thinking" is first and foremost a skill. As such it has to be practiced actively. Passively acquired knowledge will only flesh out what you already can do, it will not improve your chess all that much.

Of course if you try to follow all the variations of the commentators and constantly come up with variations on your own, you will benefit from watching games, thought the level of these games probably doesn't have much of an influence on the training effect.

Generally improvement happens outside your comfort zone. If it doesn't feel like you put something into it, you probably wont get anything out of it.


In the Dubois-Steinitz match (1862), at what point does the match become irreversibly lost for White? And why does the engine not pick it up early?

Playing the game on lichess.org, I only need to wait for a few dozens of seconds to reach the following analysis for White ninth move:

9. Nxg5 is an interesting counter-attack move that ultimately fails to bring an advantage but white is not lost. After 12. ... Nd4 13. h3! Ne2+ 14. Qxe2 Bxe2 15. Ne6 White survives.

Since 13. h3! saves White, 13. Nc3?? is indeed a fatal blunder. 13. Ne6?? also yields a mate in 7 for black.


What insights have neural networks revealed about chess?

I think NN's brought us 3 main types of knowledge about chess: Specific good types of positions, that playing positionally is viable at a high level, and that we are nowhere near creating a perfect chess engine.

Fawn pawns (6th rank pawns that are safely nested in opponent pawns) are the clearest example here. Another example would be the strength of a pair of opposite color bishops which most AB engines underestimated.

AlphaZero/LC0 both play in a much more positional manner. While hard to quantify, this basically means playing to maximize space and mobility rather than pure material.

The fact that LC0 plays so differently than SF and is about at the same level means that neither are close to perfect play. The intuition here is that as you approach optimal strength, all strategies should converge, so the difference between play styles implies that there is a lot of ability for both to grow stronger.


Suggestion for a good chess engine on Linux

Engines:

Toga II (Package).
Glaurung (Package).
Fruit (Package).

All three are installable via Ubuntu Software Center and all three are UCI compliant (ie. so runs in Chessbase Fritz, Chess for Android, and/or Arena GUI). Arena is used with FICS so you should be able to use all 3.

Except for Glaurung I used both on occasion and was very satisfied with them.

Installation:

sudo apt-get install toga2 glaurung fruit


Attempting to answer the revised puzzle:

   1.Nxe4 Qd5 2.Qg3 with the threat of 3 Ne6 winning due to double threat (4 Qxg7 and discovered attack from the Rd3).  White still carries out this threat if Black answers 2.Qg3 with either Qxe4 or Rxe4.  Presumably this is strong enough that the engines didn't even let Black answer 1.Nxe4 with Qd5.  Note that this tactic also depends on Qg3's access to d3 (after Qxe4 3 Ne6 Qxe6 4 fxe6 Rxd3) and the 8th rank (for Qxe4 3 Ne6 Rxe6 4 Rxd8+ Re8 5 Qb8!).


I don't think there are any "strategies" in the human definition of "strategy".

When you use the "common" computer engine (basically, min/max tree search), you can always check how and why the engine arrived to some particular position evaluation, but still, this is usually limited to 10-12 half-moves, beyond that it's still hard for people to grasp what was the threat, or what is the forced mate or why this particular line evaluated higher than another line: "Mate in 20?" -- "Yeah, I saw that one a few moves back" =)

When you talk about AZ or any similar NN-based software, it becomes practically impossible to reason about the moves. Once the training is over, all you get is the bunch of multi-dimensional matrices, which, once multiplied/added, give you some answer that leads to some policy chosen in this particular position.

And this behaviour is not specific to chess only. Same things happen in image recognition, pattern analysis, language processing or any area where NN are in favour last few years. You get the results, but not the explanation.

So, right now, I would not recommend to blindly follow any of the AZ patterns, because no one has a clue, er... clear understanding, why and when those patterns should be followed. It might be as minor as "if black pawn is on h6, fianchetto bishop on b2 (or g2, or both)" -- we'll never know. Not in the nearest future, at least.


Taking the knight on c6 in open Sicilians

White's d4 Knight is his best piece. Why would he trade it for a common Knight and improve Black's center?

Regarding harassing the a pawn... you can have it.  While you're doing that, your opponent will be drawing a bead on your King.

Checking 365chess.com, we see that Nxc6 is a blunder at the sub-master level.  Black wins twice as often.

At the master level, Nxc6 is not played.  There are 2 games, the latest being from 2004.  Both ended with wins for Black.

The first game is from 9/4/2001 at Glifada.  It's an ECO B56.  Andreas Kofidis is White. Marijan Petrov is Black.  White is completely destroyed in this short game after Black sacrifices a Knight on f3.  Very nasty...

Edit - ...but survivable.  White lost instantly on 17. Bxf8. It's hard to believe he didn't see the mating attack since it's pretty easy.  So he must have though he was already lost.  Instead, 17. Qe3 holds.

[fen ""]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Nxc6 bxc6 7. Bd3 g6 8.  b3 Bg7 9. Bb2 Qa5 10. O-O Ng4 11. Qe1 O-O 12. h3 Ne5 13. Na4 Nf3+ 14. gxf3 Qg5+  15. Kh1 Qh4 16. Bxg7 Bxh3 17. Bxf8 Bg4+ 0-1

This game is from 3/7/2004.  It's ECO B58.  Albert Bokros is White.  Veniamin Sergeev is Black.  Sergeev puts his Queen out there and Bokros tries to trap it.  It doesn't work out, and by move 22 Sergeev dominates the center.  White seems to be trying a cheap shot mate-in-one on move 33. Perhaps he's under time pressure.  It doesn't work out and he drops a piece.

Edit - I see now that the Knight on a5 is trapped. Black piles on the pieces until it falls.

[fen ""]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Nxc6 bxc6 7. Be2 e5 8.  O-O Be7 9. f4 exf4 10. Bxf4 Qb6+ 11. Kh1 Qxb2 12. Qd2 Qb4 13. Rab1 Qc5 14. Na4  Qa3 15. Nb2 O-O 16. Nc4 Qc5 17. Be3 Nxe4 18. Qe1 Qd5 19. Bd3 Qe6 20. Na5 d5 21.  c4 f5 22. Bc2 Ba6 23. Bb3 dxc4 24. Bc2 Kh8 25. Bd4 Bf6 26. Bxf6 Rxf6 27. Bxe4  Qxe4 28. Qb4 Rg8 29. Rbe1 Qd5 30. Rf3 h6 31. Qc3 f4 32. Rf2 Rf5 33. Re7 Qxa5  34. Qh3 Re5 35. Rxe5 Qxe5 36. Qf3 Qe3 0-1

But what's important in both of these games is that Black is granted counter-play out the wazoo - a Sicilian player's dream.  We see Queen sorties in both games on the a5-d8 diagonal.  The b6 square allows the Black Queen to get a bead on the traditionally weak (yet dangerous!) b2 square and also peer menacingly at the castled enemy King.


Loss to a master, where did I go wrong? Two knights 4.d3 (black)

8... Bd7 was a poor move. Bg4 is understandable as white often plays h3 to prevent it, but if you're going to play it at least follow through with Bh5. Bd7 only serves to give white a free tempo to play h3, which he already wanted to do, and to place your bishop on an inferior d7 square.

11... Qc7 was a bit of a lazy move. What does it accomplish? Something like 11.. b5 to gain space seems a lot more worthwhile. Even Nc6 to further clamp down on d4 after having played c5 would be better.

12.. Rfe8 seems good.

13.. b5 seems good, you're doing what you should have done 2 moves ago. Sure it's a bit weaker now that he has played a3 and b4 comes in more strongly but still a good way to contest for space on the queenside.

14.. Bf8 felt more natural to me, but i understand you want to deny f5. I just don't think it's that scary here and if he goes for d5 instead you've wasted a move.

15.. Nb7 definitely feels a lot more awkward than Nc6. Were you planning to play Nxc5 incase he takes?

16.. c4! Keeping the position closed since your pieces are more weakly placed and gaining space on the queenside was your best decision here I think. As things stand you created a powerful diagonal for his bishop if it can get to b2.

19... Qb8 is a bit ugly, but your real problem was you didn't try to free your rook with a5 on move 20. You already shut it off from the rest of the noard, it's your duty to find it a bit of activity where it's stuck and fight back against your opponent a little.

Yes 21... exd4 was wrong. Your pieces are very badly placed, you trapped your rook on a8, you moved your knight to the back rank and your d7 bishop is only  active towards the sides of the board, so opening the center even more is a bit of a crazy thing to do. Getting your knight better placed with 21 .. Nc6 and follow it up by looking to free your a8 rook with an opportune a5 would have been a much better choice. Remember, don't open things in the center when your opponent has better piece placement. Not to mention your d6 pawn became very weak after that.

After Qa1 a potential a5 just becomes even stronger. You are just missing this idea, which has been a good move for many of your turns. If you have to you can always play Nh5 or Ne8 to break the pin, Qd8 is unnecessary and loses a tempo.

29... Bb7 it's nice to see you finally got this bishop to a decent square. Giving up a pawn was worth it, but too little to late.

31.. Ne8 this is the kind of move you can play with a closed center, but with an open one it's far too passive and slow. Nh5 was a better try, though you're still lost. Be careful about exchanging central pawns, it really changes the nature of the game.

Yes, trading the Queens really didn't leave you with good chances, though to be fair you were lost either way. At least you got some good endgame experience out of it which is valuable from a training perspective. It was rough because your king was far away from his passed pawn, and with no central pawns, and pawns on both sides of the board his bishop was superior to your knight. Not to mention his pawns were already far advanced.

Well at least you fought hard, good game. Hopefully this game will give you some good opportunities  for growth.


Game drawn without enough material to mate even if opponent runs out of time?

Yes.
This is an official rule, see Article 6: The chess clock of the FIDE rules handbook (E.I.01A. Laws of Chess). Section 6.9 goes :

Except [in checkmate and stalemate cases, mutually agreed draws and resigned games,] if a player does not complete the prescribed number of moves in the allotted time, the game is lost by the 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.


Is chess a good game to fight against gambling addiction?

I have seen plenty of people, who are addicted to chess, as it can become very time consuming if you take it seriously. So yes, it could easily help people swap an addiction that most would see as potentially more detrimental for one that is more healthy.


What happens if a strong chess engine plays with itself many times?

http://tests.stockfishchess.org/tests

has information on exactly what you want. They are self-playing tests for improving the Stockfish code base.

The draw rate is roughly about 60% - 70%. There're lots of wins and losses. I believe white has more wins but it's not shown on the page.

Chess engines aren't perfect, they do make mistakes. If SF makes a bad move at move 20, the same algorithm might find the win a move later (21) because it can search deeper and further.


Oh sure, here are two examples (annotated):

This is a neat puzzle from the chess.com tactics, with white to play!

 [title "White to play!"]
 [fen "1q6/2b2ppb/4p1k1/7p/2Np1p1P/3P1Q2/6PK/8 w - - 0 1"]

 1.Ne5+ Bxe5 {black has to take else white either checkmates or wins the queen.} 2.Qg3+ fxg3+ {Pawn takes queen is forced else white checkmates} 3.Kh3 {and black has no way to avoid the imminent stalemate, any move draws!}

Sometimes stalemates are exploited strategically or tactically to force
a draw, e.g. in the game below between So and Karjakin, where black may
have had the stalemate setup in mind already when the white pawns got
to
g6 and h7.

 [title "W. So vs S. Karjakin 2017, black to move"]
 [fen "4r2k/4P1pP/2pB2P1/2P2K2/8/8/R7/4r3 b - - 0 1"]

 1.R8xe7 {black switches to antichess style of play to force the draw.} Bxe7 2.Re5+ {and white has no way to avoid the stalemate, the rook will keep checking the king where ever it goes.} Kxe5


What is the record for the most pawns, of both sides, on a file in a professional chess game?

I did some searching on Tim Krabbe's site and, in Journal Entry #278, I found that Krabbe gave a unique game in which there are 6 pawns on the c-file, 3 per side, on move 21! This is the obviously the maximum.
[Title "Sevcikova-Blichova, ch girls u12, Slovakia, 1999"]
[FEN ""]
[startply "42"]

1. e4 e5 2. Nf3 Nf6 3. Nc3 Nc6 4. Bb5 Bb4 5. a3 Bxc3 6. dxc3 Nxe4 7. Bxc6 dxc6 8. Qxd8+ Kxd8 9. Nxe5 Rf8 10. O-O Bf5 11. Be3 Nd6 12. Rac1 Re8 13. Rfe1 f6 14. Nd3 Nc4 15. Rcd1 Ke7 16. Bxa7+ Kf7 17. Bc5 Rxe1+ 18. Rxe1 Re8 19. Rxe8 Kxe8 20. b3 b6 21. bxc4 bxc5 22. a4 Bxd3 23. cxd3 Kd7 24. a5 Kc8 25. f4 Kb7 26. g4 Ka6 27. Kf2 g5 28. fxg5 fxg5 29. Kf3 Kxa5 30. d4 Kb6 31. d5 cxd5 32. cxd5 c6 33. d6 Kb7 34. Ke4 Kc8 35. Kf5 Kd7 36. Kxg5 Kxd6 37. Kh6 Kd5 38. Kxh7 Kc4 39. g5 Kxc3 40. g6 c4 41. g7 Kb2 42. g8=Q c3 43. Qb8+ Kc2 44. Kg6 Kd2 45. Qd6+ Kc2 46. Qxc6 Kd2 47. Qd5+ Kc2 48. h4 Kb2 49. Qb5+ Ka1 50. h5 c2 51. Qc5 Kb1 52. h6 c1=Q 53. Qxc1+ 1-0

For one side, the recuring record is four, as shared by many. There is no known case of quintupled pawns yet, for which the stars must align. However, as mentioned, the most notable example is the game in which the structure survived an astonishing 23 moves.
[Title "Gabor M Kovacs-Rainer Barth, Balatonbereny Open, 1994"]
[FEN ""]
[startply "43"]

1. e4 Nf6 2. Nc3 d5 3. exd5 Nxd5 4. Bc4 c6 5. d4 g6 6. Nge2 Be6 7. Bb3 Nxc3 8. bxc3 Bxb3 9. axb3 Bg7 10. O-O O-O 11. f4 Na6 12. Ba3 Re8 13. Qd3 Qb6 14. f5 c5 15. fxg6 fxg6 16. Qc4+ e6 17. dxc5 Qc6 18. Rad1 b5 19. Nd4 Qxg2+ 20. Kxg2 bxc4 21. Nb5 Reb8 22. bxc4 Rc8 23. Nd6 Rc6 24. Ne4 Rac8 25. Rd7 R6c7 26. Rd6 Rc6 27. Rfd1 Bf8 28. Rxc6 Rxc6 29. Rd8 Kf7 30. Rd7+ Be7 31. Rxa7 h6 32. Bc1 g5 33. h4 gxh4 34. Bf4 e5 35. Bxe5 Re6 36. Nd6+ Kg6 37. Bd4 Nb8 38. Ra8 Nc6 39. Rg8+ Kh5  40. Nf5 Rg6+ 41. Rxg6 Kxg6 42. Nxe7+ Nxe7 43. Kh3 Nc6 44. Kxh4

Interestingly, the 6 pawns game is an example of 2+1, 2+2, and 2+3 pawn structures. I wondered if 3+1 had ever occurred, and I found such an example. It occurs on move 10, although faster has surely been done.
[Title "Jorn Sloth-Grigory Sanakoev, CORR, 1992"]
[FEN ""]
[startply "20"]

1. c4 Nf6 2. Nc3 e5 3. Nf3 Nc6 4. e3 Bb4 5. Qc2 O-O 6. Nd5 Re87. Qf5 d6 8. Nxf6+ gxf6 9. Qh5 e4 10. a3 exf3 11. axb4 Nxb4 12. Ra4 Re5 13. Qh6 fxg2 14. Rg1 Bg4 15. Rxb4 gxf1=Q+ 16. Kxf1 Rg5 17. Rg3 Rg6 18. Qf4 Qd7 19. f3 c5 20. Rb5 Bf5 21. e4 Be6 22. d3 f5 23. b4 b6 24. Bb2 f6 25. Kg1 Rf8 26. Ba1 Kf7 27. Bc3 Kg8 28. Qh6 fxe4 29. Rxg6+ hxg6 30. Qxg6+ Qg7 31. Qxg7+ Kxg7 32. bxc5 dxc5 33. fxe4 Rd8 34. Rb3 Kg6 35. Bb2 f5 36. Kf2 fxe4 37. Ke3 exd3 38. Rxd3 Re8 39. Kf4 Bxc4 40. Rg3+ Kf7 41. Rg7+ Ke6 42. Rxa7 Kd5 43. Rd7+ Kc6 44. Rd2 b5 45. h4 Bf7 46. Be5 b4 47. Rd6+ Kb5 48. Rd7 Bg6 49. Rb7+ Kc4 50. Rb6 Bh5 51. Rh6 Be2 52. h5 Rf8+ 53. Kg5 Bd3

This leaves 4+1 and 4+2 pawn structures are still yet to known to me. 4+1 has probably occurred, but I severely doubt the existence of a 4+2.
Lastly, here is a game in which tripled pawns occur on move 7. However, the actual record may be 6 moves, if not 5.
[Title "Gerhard Kiefer-Peter Krauseneck, Bundesliga Germnay, 1982"]
[FEN ""]
[startply "13"]

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. dxc5 Qc7 6. Nf3 Bxc3+ 7. bxc3 Qxc5 8. Bd3 Nc6 9. O-O Nge7 10. Rb1 Qxc3 11. Rb5 Nd4 12. Nxd4 Qxd4 13. Rxb7 Qxe5 14. Bb2 Qd6 15. Rb3 f6 16. Qh5+ Kf8 17. c4 dxc4 18. Bxc4 Qc6 19. Bb


If you set the contempt factor really high in an engine it will likely be able to play armageddon. Contempt factor is how much it accepts (or doesn't accept) draws. If contempt is high enough it should view a draw just as bad as losing.
https://www.chessprogramming.org/Contempt_Factor is a good article to read on contempt factor if you're unaware of the concept.


Who is eligible to play in the 2017 FIDE Asian Zonal 3.3 in Tagaytay, Philippines?

That tournament is for federations in zone 3.3 (basically SE-Asia and Japan). Australia is in zone 3.6. So you could only play at the Asian zonal 3.6 in Auckland.


Can playing too much chess affect your performance?

At least for some players, yes, although how many games, the type of games, and in what period of time, causes burn out, I would assume varies from player to player. I've been reading "Bent Larsen's Best Games," and he mentions how he was drained after playing several consecutive events, but after a month's vacation, came back refreshed.


I would try breaking your games down by sub-goals and examine the moves leading up to achieving that sub-goal which gives you an easy metric on how well the set of moves performed.  Of course, the harder part is to assess your sub-goals.  Did you have the right overall plan?  Did your sub-goals improve your position?  I'm not sure if breaking your evaluation down to the "set of moves" level will ultimately be useful.

For instance, you can set a sub-goal of controlling the c-file so the set of moves that contribute to doubling the rooks on the c-file evaluate as "good".  However, if your opponent is invested in an attack on the king-side, your sub-goal might be faulty.

Take a look at some middlegame books, games collections, and/or tournament books.  Try something like IM Jeremy Silman's "How To Reassess Your Chess" and/or GM Bronstein's annotations of the Zurich 1953 tournament.

The former will give you some ways to approach thinking about your position and formulating goals while the latter will delve into the thought process behind the moves of real games of grandmasters.


What are the advantage of sicilian defense for black?

The sicilian defence is not just one opening, it is a whole family of variations, that are quite different from each other. So this breadth of possible choices surely contributes to the popularity of the sicilian.

The sicilian variations are also usually quite sharp. This makes it easier for black to create winning chances. In the open sicilian (which is usually the main line) black gets the longterm advantage of two centre pawns against one centre pawn and the open c-line. The other defences against e4 don't have quite such a big disbalance.


If given infinite processing power, is there an algorithm that would play chess perfectly?

Does an algorithm exist?  Yes.  According to Zermelo's Theorem, there are three possibilities for a finite deterministic perfect-information two-player game such as chess: either the first player has a winning strategy, or the second player has a winning strategy, or either player can force a draw.  We don't (yet) know which it is for chess.  (Checkers, on the other hand, has been solved: either player can force a draw.)
Conceptually, the algorithm is quite simple: construct a complete game tree, analyze the leaf nodes (the game-ending positions), and either make the winning initial move, resign (if the opponent has a forced win), or offer a draw (if the position is a draw).
The problem lies in the details: there are approximately 1043 possible positions, and an even larger number of moves (most positions can be reached in more than one way).  You really need your infinitely-powerful computer to take advantage of this, since a computer that can take advantage of this algorithm either can't fit in the known universe, or won't finish computation until sometime after the universe ends.


I'll leave others to point you a correct database for the games because I'll focus more on the statistical part.

First, you need to ask yourself what you want to analyze. If you don't know, you should really ask yourself what problem you want to address. Your question simply say "I want to do something, but I don't know what to do.". There're infinite ways how a database of chess games can be analyzed. I'll point to you for some areas.

Whether white has an advantage

Given a large data set, if we assume the games are independent we might strip away the draws. Then we might assume a binomial distribution with p=0.5 and try to detect statistical significance. However, this approach assumes that the players are equal.

There's rumor that Carlsen got most of his points from players older than him (last generation like Anand) but suffers against like Caruana and Giri. Is that true?

You might use a two samples-mean t-test or something like that.

Whether Elo rating is really inflated
Given a set of games between two players (or computers), is one player really better than another?

For example, Carlsen has beaten Nakamura many games without a loss. Does it mean Carlsen is a better player? Did that happen because Carlsen was simply lucky.

Correlation between world-number one and world champion

Is there a positive correlation? Are they independent?

Whether the Elo rating system really make sense

There were some articles on Chessbase about it a while ago. I don't remember the names so you'll need google yourself.


It's not check but the next move is checkmate

If it is your opponent's turn to move and none of your opponent's pieces can move other than his king, and the king would be in check on any square it could move to, we would call that stalemate.
In case of stalemate, neither player wins – the game is drawn.

Here are a few examples:

A simple one with just 3 pieces on the board with Black to move:

Here, the black king has nowhere to go, the squares h8, h7, g7 and f8 are controlled by the white queen and f7 is controlled by the white king.

Another position of stalemate with a few more pieces on the board, again with Black to move:

Black has 2 pawns and his king. His pawns can’t move forward or capture any pieces and his King can’t move anywhere as its surrounding is controlled by the pieces as shown in the image.

A little more complicated one with even more pieces on the board (white to move):

Positions like this one occur only very rarely! I believe it is a composition by someone and hasn't occurred in a real game.
Here all the pieces are on the board and yet White has no moves to make. All his pawns are fixed, most of his other pieces are blocked by his own pieces and the only 3 pieces which have space to move are the rook on g3, the knight on d2 and the king on e1. None of these three pieces can move since that would leave the king in check! Unfortunately this is a draw, because it is a stalemate.


The most pins in a real game position that I know is 3 from an extremely famous game nicknamed "On Pins And Needles" by chessgames.com. Agadmator covered in a YouTube video a few years ago.
[Title "Geoff Chandler-Richard Kynoch, Edinburgh Club Championship, Scotland, 1981"]
[FEN ""]
[startply "53"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4 Bg6 6. Nge2 c5 7. Be3 Nc6 8. dxc5 Nxe5 9. Nd4 Rc8 10. Bb5+ Nc6 11. Qe2 Nf612. O-O-O Be7 13. h4 h5 14. f3 Nd7 15. gxh5 Rxh5 16. Rhg1 Nxd4 17. Bxd4 Qc7 18. Rxg6 fxg6 19. Qxe6 Rf5 20. Nxd5 Qd8 21. Qxg6+ Rf7 22. Re1 Kf8 23. Qh7 Ke8 24. Qg8+ Rf8 25. Qxg7 Rf7 26. Qg8+ Rf8 27. Nf6#


[FEN "K3k2n/7n/rr1R3N/7n/8/8/4BQ2/4R3 w - - 0 1"]

1. Bxa6#

Here is a much more simple situation where White only has only one legal move, which is a discovered checkmate.


As a decently strong atomic player fairly connected with the atomic community including the strongest players, I feel I can answer this one. The short answer is: white probably wins, but there is no weak solution nor does it currently seem achievable to find one.

Outcome?
The current consensus among the strongest players and opening theoreticians is that White wins, but as of yet there is no public and/or convincing and exhaustive proof. Opinions differ on whether many different openings and lines are winning or drawn; however there tends to be agreement that the lines after 1. Nf3 f6 2. Nc3 Nh6 3. g4 (the first tabiyas in this rabbit hole would be after 3...c6 4. d4 e6 5. e4 f5 6. Nh4 or exf5 with many sideline branches on black's 2nd, 4th and 5th moves) give no hope for black if white plays perfectly (and by "perfectly", that tends to be 20+ move deep, widely branching theory in complicated middlegames, leading to nontrivial endgames). That said, from a practical point of view, these are also not easy to meet as black at high levels.
This, however, does not constitute a weak solution. We do not have an exhaustive (or even very aggressively pruned) game tree that leads to white wins everywhere. All we have is a lot of opening theory where both sides play sensible moves and where with precise play by white, just about everything leads to what seem to be winning white endgames. The branching factor for plausible moves appears to be too high for a weak solution to be within reach, though -- in addition, the endpoint endgames themselves may not be easy to evaluate for humans, and not for engines either.

A word on engines
The modern engine for atomic analysis is Stockfish 9, but using the 2018 or earlier builds, as more recent builds seem to give pruning issues leading to outright blunders and misevaluations in certain cases. Other engines exist like Atomkraft (an older engine), and offer different but also strong opinions.
A major shortfall of atomic engines in general, though, is their endgame knowledge is poor. One commonly-occurring situation is a pawn endgame where one side is up a whole bishop, yet cannot win because the bishop cannot take an enemy pawn, nor can passed pawns be created. This is known as "pawnitisation" (common enough to have a name since more than a decade ago!) and engines cannot detect this reliably, often giving a +3 to +4 evaluation to draws. They also, due to the horizon effect, tend to misevaluate simple endgames where one side is up two pawns for minor (yes, up) with rooks on the board, which is winning in general but can take many moves.
While 6-man tablebases exist for atomic, these do not solve the problem; many of these endgames have more than six units on the board.
This leads to the issue that engines, despite being stronger than humans (still not completely invincible though!), may not be fully relied on to accurately evaluate a position.

Conclusion
An engine-only "solution" of atomic would be met by skepticism due to their inability to accurately judge a fair number of endgames. In fact, even an engine-assisted weak solution would seem unattainable, also because of the high branching factor of plausible moves, and high depths (think at least 40+, probably more than 60+) needed for reliability.


What would you suggest I play vs. the Ruy Lopez, if I already play the Two Knights Defense vs. 3. Bc4?

There's a simple reason for which 3...a6 and 3...Nf6 are by far the most common replies to the Ruy Lopez: they're the most solid for black. It's very hard to force white into playing something dynamic without comprimising your own position. Of course, you can try something like the Schliemann Defence with 3...f5, though objectively this is dubious for black. However, assuming you aren't playing against titled players, it can still be worth trying if you have good preparation and if you trust that your tactical ability is better than your opponent's. Another option instead of the Schliemann is the so-called "Siesta variation", which features a similar f5 pawn break, though black scores better here than in the Schliemann.

[FEN ""]
1. e4 e5
2. Nf3 Nc6
3. Bb5 a6
4. Ba4 d6
5. c3 f5

This leads to very dynamic play. GM Laurent Fressinet used this in 3 different games at the World Blitz Championship 2017 against other GMs, and won all 3 of them. GM Valeri Yanderimov also has many games in this variation, with mixed results.

Alternatively, if you want something different, you can always try the Cozio defense, both the standard and the deferred variations. This is more solid, though players at lower levels are less likely to be prepared in this opening, and the resulting positions can be surprisingly dynamic with potential pawn storms and black having a strong bishop on g7. The answer to this question provides good insight into the differences between the direct and deferred versions. Of course, the dynamic character of the Cozio depends largely on what white decides to play, and thus you still have to be ready for more quiet or more drawish positions.


Are there any tri dimensional chess rules utilising traditional starting positions?

If you search for a guy by the name of Larry Smith, he has produced numerous rule sets for tri dimensional chess, although they appear to be directly reverse engineering games played on the Star Trek television series.
The official rules of the World Tri Dimensional Chess Federation start with the king and queen in the centre of the rear rank, flanked by two bishops, with the knights and the rooks assigned to the rear ranks of the attack boards.