1. e4 e6 2. d4 c5 - is this opening worth it?

You need to realize that just because someone gave it that name on move two, that it is certainly going to transpose to another opening with a different name. When determining what opening is played, classification takes place from the end of the game, and moves backward so the last known opening position is considered the opening that was played. If you start 1.c4 Nf6 2.d4, it is already no longer an English opening, for example.

So that Alekseenko-Salgado Lopez game is actually ECO B54, a variation of the Sicilian, listed as "unusual lines" only because black refrained from Nf6. Had he chosen that move on move 6, which was the most common move there, it would have just been a mainline Scheveningen.

After 1.e4 e6 2.d4 c5, you are going to get a mainline Sicilian, or a Benoni (the position after 1.e4 e6 2.d4 c5 3.d5 ed 4.cd). If black plays Be7 it is a Schmid Benoni, or a regular Benoni if black plays g6 and Bg7, but where white played the less-common exd5, which is probably a minor win for black, but I have always enjoyed those positions with white.

For the record, in both Benonis, the pawn on d6 is not as big a weakness as you seem to think it is since the d-file is not open, and the only pieces that can typically get at it is a B on f4, and a Nc4/e4, but it is still easily defensible.

There is nothing wrong with this move order as long as you are willing to play the Benoni and Sicilian, but that seems odd considering the offer of playing the French on move 1...e6.


Significant and efficient advice for amateurs

I don't like any of these answers as they are too wordy and assume a certain level of skill firsthand.

So, I would say:

1: Pay attention to what your opponent's move was. Many players get so focused on their own pieces they overlook what the opponent is doing, and suddenly they are dropping material. Chess is like a dance so pay attention to what your partner (opponent) is doing.

2: In association with #1, what does your opponent's move do? What are it's consequences? does it attack something? Does it leave something unprotected? Pay attention to that. Chess is like a conversation with a long-time friend. Let the move speak to you and give you all the information it has and don't interrupt the story it is telling you.

3: Do the basic "Captures, Checks, Threats" after every move. Just by looking at the board and mentally going over every capture, every check, and every clear threat, you will avoid losing material, and losing material is the single biggest problem for newbies. Chess is like boxing - you have to be able to read and anticipate what "punches" your opponent plans to throw at you. There are no surprises in chess - everything is before you. You only have to develop the skills to look closer to find what truths the position is telling you.


I played my first (rapid) tournament recently and I wanted to calculate my ELO

OK, so the tournament was the Rattenberger Schnellschach-Open 2019 Tiroler Einzelmeisterschaft im Schnellschach It was a Swiss tournament. Here are your results from the tournament.

One of your opponents, Karl-Heinz Staudacher, has no rating. You should exclude your result against him altogether.

One of your opponents, Manuel Keßler, has a standard rating but no rapid rating. In the listing his standard rating has been used for pairing purposes and I believe this will also be used in rating calculations.

That means that you scored 4/8 against rated opposition. Accordingly (8.21a and 8.22) your rating will just be the average of those 8 opponents' ratings = 1885.5 which will be rounded up for display as 1886. If you play more FIDE rated rapid tournaments in June then the results from these tournaments will also be used in your calculations.

  I don't understand the point 8.21 of the handbook

This first says that if you score 0 in your first tournament then all your results in that tournament are excluded from the calculations. This is usually a good thing because it means that results which would give you a low rating (or no rating at all if it works out at below 1000) are not used.

Coaches of weak players playing their first tournament and losing their first few games often advise the player to either lose the last game or two or to pull out of the tournament to take advantage of this rule.

The rest is just giving the rules for calculating rating in case of round robin and Swiss. Your tournament was Swiss so you should use those rules.


What does "TPR" mean in chess tournament reports?

It means Tournament Performance Rating.

Very roughly a TPR of 2551 means that the results this player has achieved in this tournament would have been expected of a player rated 2551.

That's always a bit problematic. Say you scored 100% against a group of 1500 players, what kind of player would have expected to score that? Well, a 1900 player probably, but also a 2800 player. And many methods make your TPR go down if you win against a much lower rated player, because they are based on the average rating of your opponents. But it's a rough measure of how well a player did.

There exist various methods to calculate it that I don't have time now to go into now.


c4 is the usual beginner's mistake of releasing the tension unnecessarily. With the pawn on c5 you exert some pressure on d4 which can be increased with moves like Ne7-c6. When the pawn moves to c4 that pressure disappears.

If you played Ne7 instead then taking the c5 pawn is bad for white. You are not going to retake immediately but instead play Nc6. This gives white the choice between allowing you to recapture on c5 with the bishop with gain of tempo or allowing you to take the more important e5 pawn. Instead of taking on c5 white will want to develop his queenside pieces but this is awkward in the current position. His dark squared bishop is problematic.

  After 9. Qc2 b5 10. a4 a6 11. axb5 axb5 12. Rxa8

This is "hope" chess. You "hope" your opponent is going to make some bad moves and then your bad move magically becomes a good move. If you want to improve then you have to stop doing this.

Your opponent is not going to play Qc2 because if the c file opens then he wants a rook on that file not the queen. Qe2 is better. He is also not going to play 10. a4. He is going to play 10. b3, immediately attacking the front of your pawn chain.

Furthermore you are a long way behind in development with your king still stuck in the middle. You should not be wasting time on further pawn moves, particularly ones which threaten to open the position leaving your king exposed to attack. Ne7 is more to the point, developing a piece and getting you one move closer to being able to castle.


Why do people say blitz chess can be bad for your chess?

I am answering only as an expert player, so who am I to answer this, but I think that "blitz ruins your chess" was a very popular view some time ago rather than nowadays... Anyway, given the very limited time at your, and your adversary, disposal, in blitz chess a player is not generally searching for the best move(s) but the one that gives you most chances. This may encourage, in the long run, a player to "stay away" from very deep considerations, tactical or strategical, and this is ultimately not good for improving chess strength. When you face strong players with plenty of time at their disposal you have to find the best moves, because they haven't 30 seconds on the clock or so, unless they are in zeitnot, to answer you.


slav defense, black's bishop early development punishment

As far as I know it is consensus that the two variations you gave starting with 5.cxd5 are indeed the best possible way to play as White.

Now 4. ...Bf5 is a bad move, as Black is either forced to give up a pawn( in the first variation) or give up the center(as in the second variation), but despite these tactical flaws it is still a sensible developing move, so you really should not expect to gain more than you do in the given variations.

That being said, White does have different options available, but none of them is actually objectively stronger. In fact, if White is careless this variation can easily result in an equal or even slightly favorable position for Black. There is a famous game Yanovsky - Capablanca, that beautifully illustrates this danger.


Expanding on the great comments of @David and @Timothy Chow, GM Nikolai Krogius talks about the role of the residual image in his book Psychology in Chess. This is an image that stays  and blurs the calculations. The residual image is the transfer of judgment from a past position to a new situation. The past then acts on the present.

To combat this residual image and to improve concentration, Krogius recommends practicing blindfold chess or analyzing without using a chess board. By not looking at the board, the player must constantly check the position of the pieces, thus erasing the residual image.

Here is an example of the residual image. At the beginning of the position the Bishop in b3 controls the square g8, but not ... at the end.

[FEN "r3k3/1p5p/p2R4/4p1Q1/4P1bP/PBq5/6P1/5K2 w - - 0 1"]
[title "Ilyin-Genevsky - Nenarokov, Moscow 1922"]

1.Bf7+! Kf8 2.Qh6+?? (2.Rf6!+-) Kxf7 3.Rf6+? (3.Qxh7+ Ke8 4.Qg6+ Ke7 5.Qf6+=) Kg8! {and now Black is better!}

Check also this article on ChessBase India, which asks your question

  *We often see top chess players not looking at the board while
  calculating. It seems that their attention is somewhere else, yet
  after a few minutes they make the move without having even glanced at
  the position. What do you think they were doing for the last few
  minutes? Well, they were thinking in their head. They did not need to
  see the chess board to calculate the variations. They could do it in
  their head. So how do these super GMs calculate without a chess board?
  How are they able to make complex decisions in their mind, which
  normal players cannot fathom.

They welcome GM Vidit Gujrathi on how to calculate better in blindfold.


We were all there, it is normal.

It is a psychological problem, but without 3+ sample games there is nothing I can do to help you. If you could edit your post with 3+ games that illustrate typical scenario, I could engage in solving your problem with greater effect.

Without the games the best I can advise you is :

Know your opening -> ask here if you need help;
know how to play your middlegame pawn structure ( isolated pawn / d4 vs c6 + e6 / sicilian formations... ) -> ask here if you need help;
Make smart exchanges in the endgame -> ask here for help by posting the endgame position;

To cut it short, work on your technique and this problem will solve itself. As for psychological aspect of this problem, keep your nerves calm when you reach good / winning position, as that is the point when "mind tricks" will start to mess you up.

This is especially true when you reach winning position, the "victory rush" will loosen your sense of danger and you might miss opponent's saving tactics. Even if the game is still won for you, the psychological blow it will make will be devastating and will shake you so much that you might lose the game in the next move ( happened to me countless times ).

This is not the case when you play other opponents because your mind is calm, and you are able to control "victory rush" by carefully and objectively assessing the position. This is the place that you must work on hardest -> keep your emotions under control during the game and assess position objectively.

As soon as you feel fear that you will "f*ck it up" because he's lucky or destiny chose him to punish you for your chess sins, STOP PLAYING. Take 1 minute to breathe and calm down. This is the crucial moment in the game, so use that 1 minute to calm down -> no thinking, calculating, assessing lines, NO! Just breathe and calm down, that is all you need ( you can always spare a minute even in blitz games ). Tell yourself "I've got this!" and just aim not to lose the game. Your main goal is not to lose, so even if you draw the game in an overwhelmingly won position for you, it is still a success as you broke the losing streak. In your mind he will no longer appear as "SuperChessMan", but after not losing that game he will become simply yet another player. The moral boost you will feel in that moment will disperse all the previous psychological barriers and you should be able to engage him successfully in the next game.

Another thing that helped me was analysis of my own games against such opponents. You should always do this when you lose the game, always! Just turn on the engine and see its suggestions, that is enough for a start. You can always post your game here for help, we don't bite people's heads off! :)

For now, this is all the advice  I can offer.

Good luck!


Crazyhouse Chess: Playing with a real board and overall popularity?

Very boring answer: when I was at the university, we used to play it on a real board with two sets of pieces. Whenever you take a piece, you exchange it with one of the correct color.


As you probably know, sometimes the word "pieces" itself is used for that (you can say for example: white has two pieces and three pawns left). But that isn't very practical to use.

The only solution I can think of is using light pieces, heavy pieces and a king.

Not a one word, but at least it can be used in your sentence.


Is there any more purpose to various openings than to get a positional advantage?

This answer may seem long, but to understand openings one has to understand some important positional concepts first.

Space

Space in chess can be loosely described as the number of squares controlled by friendly pieces. Having more space is often a good thing for two reasons.
Firstly, it gives you a freer position and you will have more options than your opponent based on the fact that you have more space on the board to work with. Secondly, if you have more space it means that your opponent will have less space, which will make their position cramped and difficult to play since many of the opponent's pieces will need to occupy the same squares.

Piece activity

Piece activity in chess can be summed up in the following question:
What good are the resources you don't utilize?
An active piece is one that influences the board in a significant way, such as a centralized knight or a rook on the seventh rank. Active pieces are mobile, and can often perform many important aggressive and defensive tasks by themselves. They are often a great nuisance to the opponent, whose pieces are threatened and restricted by active pieces.

Piece coordination

Piece coordination is used to describe how well your pieces work together. For instance, two rooks on an open file are considered very powerful because they typically coordinate very well with each other; together they possess double the power of a single rook while at the same time they can defend each other from attack. Pieces who coordinate well are in general stronger than their sum parts, while pieces who coordinate badly are the exact opposite. Piece coordination is an important positional factor which will make or break your position.

King safety

This one almost goes without saying; a safe king is less likely to get mated while an unsafe king is more likely to get mated. As simple as this concept is, it very important to pay attention to; many players have fallen for the trap of leaving their king slightly too unsafe at one moment, and have gotten destroyed as a result.

Material count

The material count is the most simple and intuitive positional factor in chess, and it is easy to assess at any given moment of the game. Since it is so simple to use, many players tend to overestimate its importance, myself included. The thing to remember about the material count is that it is actually "just" a positional factor among others, and thus it can be trumped by other positional factors. While important (especially in the endgame, when few pieces are left, the one with the advantage in material count tends to have a great advantage), it is not necessarily the most important one; for instance, if you get checkmated due to poor king safety it doesn't really matter much that you have an extra queen compared to your opponent.

Beginners are often advised to follow the basic opening principles, since they are quite simple and will help them coordinate their pieces reasonably well and fight for space, while also getting the king to relative safety early on. The long-term goal of this strategy is simply to get a playable position out of the opening, and for beginners this is a perfectly acceptable outcome of the opening.

Past the beginner stage, chessplayers will often start playing some theoretical opening lines to get an edge over their opponent.
Different opening lines are designed to try and get an edge by emphasizing different positional concepts; for instance many gambits tend to ignore material count to some degree in favour of piece activity and coordination (and often also reduced safety for the opponent's king), while other openings may place emphasis on getting a space advantage and letting the opponent suffer in a cramped position for the long haul.

To answer your question: I'd say that in order to connect your opening to a long-term goal, you first need to understand which positional concepts your opening is designed to emphasize. This can be easy or difficult depending on the opening you look at. As a novice player you could try to study your opening in terms of how well it adheres to the basic opening principles you know. The principles are sound and shouldn't be broken willy-nilly, so if they are broken there will be a good reason for it (if the opening line is sound, that is). This concrete reason will often have to do with one or more of the above-mentioned positional concepts in this post, but sometimes it is of a more concrete nature.


No. MCTS is generally not deterministic. However, it's not that bad given how powerful Google's machines were.


Are chess players getting better, given the same rating?

How would say a 1700 rated player of say 50 years ago who is no longer .around go against a 1700 player of today?

Speaking as a player who was around 50 years ago and was rated the equivalent of 1800 in 1973 (my BCF grading was 150 with a generally accepted conversion formula of ELO = BCF x 8 + 600) and is rated 1718 today I'm pretty sure I would beat my 17 year old self.
OK, the me of 2021 is probably not very objective but I am sure that if I managed to reach an even endgame against my 17 year old self I would be a very strong favourite. The reason being that in 1973 almost all the chess I played was at a time control of either 30 moves in 75 minutes or 36 in 90 with adjudication after 3 hours play. The 17 year old me hardly ever played an endgame and so wasn't that good at endgames.
That kind of time control was the norm in England 50 years ago and probably in much of the non-Soviet world. Weekend tournaments where large numbers of people played 3 full games a day with a time control of all the moves in 1 hour didn't come in until the mid to late 70's.

Does this mean that chess ratings over time have grade deflation?

From my personal view absolutely, yes. However my single example of personal experience is highly subjective and one case is meaningless.
To get a more objective view of whether there has been rating inflation or deflation I think we have to look at historic data. There is FIDE rating data available going back to 2001 on the download page of the FIDE rating website and back to 1971 (unofficial data back to 1967) on the Olimpbase site. These data can be downloaded and analyzed to get more meaningful evidence.
Comparing today with 1971 is problematic because in 1971 there was a rating floor of 2200 (nobody under 2200 was listed) so there were only 547 players and obviously nobody with a FIDE rating of 1700. However we can try and maybe also, more meaningfully compare today with 10 years ago.
The January 1971 list is here on Olimpbase. There we can see that the highest rated player, Bobby Fischer, is at 2740, more than 100 points lower than today's number 1, Magnus Carlsen on 2847. There are 16 players at or above 2600, 82 at or above 2500 out of 547 at or above 2200.
The comparative figures for March 2021 are 264 above 2600, 946 above 2500, 3111 above 2400 and 17334 above 2200.
January 1971
Players above 2600 = 16 (2.9% of over 2200s)
Players above 2500 = 82 (15% of over 2200s)
Players above 2400 = 278 (50.8% of over 2200s)
March 2021
Players above 2600 = 264 (1.5% of over 2200s)
Players above 2500 = 946 (5.5% of over 2200s)
Players above 2400 = 3111 (17.9% of over 2200s)
To me that looks like it is comparatively much harder today to get to GM / elite level than it was 50 years ago but the difference in sample sizes detracts somewhat from the percentages. And, of course, it doesn't say much about what is happening at the 1700 level.
If we go back 10 years and compare numbers and percentages (using total rated players) at 1700, 2150 and 2600 we get:
March 2021
Total rated players = 363590
Players rated above 2600 = 264 (0.07%)
Players rated above 2150 = 29392 (8.1%)
Players rated above 1700 = 169425 (46.6%)
March 2011
Total rated players = 126693
Players rated above 2600 = 223 (0.18%)
Players rated above 2150 = 29575 (23.3%)
Players rated above 1700 = 111529 (88%)
Again it looks like it is relatively harder today to get to a higher rating than it was 10 years ago but that might just be a reflection of the expansion in the number of FIDE rated tournaments for lower level players. But, yes, it does look a bit like rating deflation to me.


Which openings (black/white) should man play against a player, who is not good at endgame but a tactical beast?

I typically play double fianchetto (g3,b3 with white and g6,b6 with black); further pawn structure depends on responses; also sometimes playing b4,g4 - but that's more for speed chess; as general idea - some closed position where smart maneuvering matters and no direct encounters in opening if possible - or open 1,2 files and try to exchange few pieces


What was the source of randomness in the Alpha Zero vs Stockfish match?

I've noticed AlphaZero played 1.d4 and 1.Nf3 in http://www.chessgames.com/perl/chess.pl?tid=91944&crosstable=1. Possibilities:

Mutlithreading (any software engineer can tell you it's not deterministic)
Monte Carlo Tree Search (the algorithm draws random paths, so it can't be deterministic)

Please note while the model's parameters are "fixed" (your own words), the actual move might be different. We don't have the source code for AlphaZero, but multithreading and MCTS are likely two major casues.


Which gambits have been most successful?

According to these statistics from 4 million games, the Marshall Gambit of the Semi-Slav defense is the most successful with 58.4% wins. I only counted gambit openings that had more than 1000 occurrences in the database.

The least successful gambit appears to be the Latvian Gambit with only 41.1% wins.

Note that since the database does not discriminate against older games, the statistics may not necessarily reflect the possible outcome of an opening if it were played today.


Do you sign papers when joining a chess club?

Yes, usually you sign papers when you join a club. After all you commit yourself to paying the membership fee (even if in your case there is none) and for a financial commitment there has to be some kind of legal foundation. And there are other issues like whether it is allowed to play for several clubs, whether you get a national rating or an Elo and what happens with your personal data in that case.

But this shouldn't be a big deal. If the contract is a very long and complicated affair, I would get suspicious, too. Best take the contract home and show it to your parents, or somebody who can assess it.

Edit: This is the way it is usually done in Germany. But clubs are taken very seriously in our country. ;-) And our chess league system is really very thoroughly organised, so maybe that plays a role as well. Basically every club has a set of rules, pretty much like a democratic constitution, which you have to accept by signing. And although you can be a member of many clubs, you can only be an "active" member of one club at a time, so that is usually specified in the application form as well. (Except when you are a women, then you can be "active" for the normal league system for one club, and "active" in the women's league for another club …). Then you have to agree that your personal data is used for all kinds of nefarious purposes (like rating), and possibly acknowledge that it will take x month to end the membership (So if you end the membership too late, another payment is due).


I found a problem that perfectly fits your description! I’ve played the position back a move for the double step.
[Title "Kurt Keller, Stuttgarter Nachrichten & Südwest Presse (Ulm) 1993, Mate In Three"]
[FEN "5RbN/5ppk/5P1P/5P1K/8/8/8/8 b - - 0 1"]
[startply "2"]
[startflipped ""]

1... g5 {Now White mates in three.} 2. fxg6+! fxg6+ (2... Kxh8 3. gxf7 Kh7 4. fxg8=Q#) 3. Nxg6 Bf7 4. Rh8#

If the Games magazine flipped the position, then this is a problem with all pieces in one corner, on the first three files and last four ranks, a short number of moves, and an en passant key! Even it wasn’t flipped, your mind might have altered your memory. Since the problem itself is from the early 1990’s, it’s safe to to assume that the Games magazinre reprinted it for show.


How to keep improving when missing advanced knowledge prevents finding the answer to tactical puzzles

I think the most important thing to do right now is to clarify exactly what the problem you're having is. From the somewhat vague example you gave I have a suspicion, but I can't be sure. I think that your problem with the tactics is that the way you evaluate the resulting positions from the tactical sequences you calculate is too simplistic, in this case by being over-reliant on the material count while not taking other positional factors into account.
From the way your example is phrased, it seems to me like you can understand that the resulting position from the correct solution is better than the one resulting from your solution when you compare the end positions next to one another. So it might be a case of you knowing that you're solving a tactical problem, and therefore you assume that you're looking for a way to win material, causing you to "tunnel-vision" when solving these tactics exercises.
In this case, the solution to your problem is rather simple in nature: just be aware that finding the best continuation to a problem is not always the same as finding a way to win material, it's all about ending up in the best possible position.
Another potential problem that could be the issue for you is that you stop your calculation too soon; sometimes it's necessary to calculate further than you originally expect to see why a continuation is good or bad, and if this is the case for you (which it could be, judging by your example) then you need to ask yourself why you stopped calculating at the point that you did. Why didn't you notice that you needed to calculate a few moves further? And if you were to calculate further, would you have been able to see what was wrong with your line? In this case, it is vital to be aware of this if you're ever going to fix the issue in the first place, and to appreciate the importance of calculating to the very end of the line, where the position has clarified to the point where it's easy to evaluate directly.
In the end, I seriously doubt that all your problems with these more "advanced" tactics are based in a lack of "advanced knowledge" of positional chess. I think it has more to do with your approach/attitude to calculation might be somewhat misguided and/or overly simplistic. But in the end, this is hard to judge from one vague example, and I might be way off in my assessment of your particular case. In any case I felt that what I've stated here needed to be stated so that you are at least aware of some of the potential pitfalls with tactics that are easy to overlook if you're not aware of them.


Is the advance Caro-Kann becoming less popular?

Summary

From the plot of games played under the Caro-Kann ECO codes (B10-19), the advance variation (in B12, but B12 does hold some other miscellaneous variations) has been consistently the most popular line since the 1990's and peaked at 1,803 games in 2008.

Methodology

I extracted the games from the Fritz for Fun 13 into PGN format
I ran the following R code, which extracts the year (mandatory) and the ECO (optional). The games are filtered to ECO codes B10-19 (Caro-Kann) and for games from 1927. Why 1927? That is when it debuted at the top:

  He [Capablanca] used it [the Caro-Kann] in his crushing strategic destruction of Aaron Nimzowitsch in the great New York tournament of 1927.

Source: The Caro-Kann: Move-by-Move by IM Lakdawala

The raw number of games are then plotted over time. Unfortunately my data only goes to 2009

library(ggplot2) # For making the charts look nice

dat <- readLines("C:/Users/Peter/SkyDrive/Chess/Fritz for fun 13 database.pgn") # Read in the data from a local file

eco <- dat[grep("\\[ECO ",dat)] # Extract the ECO, if there is one
eco <- sub("\\[ECO \"","",eco)
eco <- sub("\"\\]","",eco)

year <- dat[grep("\\[Date ",dat)]
year <- sub("\\[Date [\"]","",year)
year <- sub("\\..*","",year)
year <- as.numeric(year)

ecoindex <- grep("\\[ECO ",dat) # Find which lines have an eco
yearindex <- grep("\\[Date ",dat)
yearindex <- yearindex + 5 # The date is always the 3rd pgn tag and is mandatory. The ECO, if present, is the 8th tag
matchindex <- yearindex %in% ecoindex  # This code finds which games have both a year and eco tag

year <- year[matchindex] # Filter out games without an ECO

countgame <- table(eco,year)
countgame <- as.data.frame(countgame) # Convert to a data frame

Carocode <- paste("B",10:19,sep="") # ECO codes for the Caro-Kann are B10-B19

Carogame <- countgame[which(countgame$eco %in% Carocode),] # Keep the data for the Caro-Kann ECO codes

Carogame$year <- as.numeric(as.character(Carogame$year))
Carogame <- Carogame[Carogame$year>=1927,]

p1 <- ggplot(Carogame,aes(x=year,y=Freq,group=eco))+geom_line(aes(colour=eco)) # Plot count of games

p1 <- p1 + ggtitle("Number of Caro-Kann games over time") + ylab("Number of games")

print(p1)


Is this a good idea for starting the game?

It's definitely not a good idea. If it were one, there would be a real opening for it. One problem with moving all your white-squared pawns 1 space forward, is that you lose so many moves developing your pieces. However, this is the 'small' disadvantage. The big one is, that all of your white squares are very weak.

Look at this position:

[fen ""]
1. a3 e5 2. c3 d5 3. e3 e4 4. g3 Nc6

Black just needs to put his pieces on nice squares like for example Ne5 or Nc4, Bg4 with Nf6. Also a disadvantage is that you lose much space. Your knights have nearly no squares, where they can move. Bc1 is completely useless.

If you lose your white-squared bishop, the black pieces will destroy you, because you can't defend all the white squares.


Can a King and a Knight force stalemate against a lone King?

An exhaustive computer search shows that as expected K+N cannot in general
force stalemate against a lone K.

In fact, the defending King can avoid stalemate as long as it's not on
one of the six-square triangular neighborhoods of the corners
shown in the following diagram

[Title "Danger Zone"]
[fen "kkK2Kkk/kK4Kk/K6K/8/8/K6K/kK4Kk/kkK2Kkk w - - 0 0"]

even on the long edge of each triangle (the twelve White Kings
in the diagram) stalemate can only be forced in a few special positions.
Namely, Kb2 to move can be stalemated by force only from this position

[Title "Mutual Zugzwang"]
[fen "8/8/8/2N5/8/8/1k1K4/8 w - - 0 0"]

and its reflection about the a1-h8 diagonal; and Ka3 to move is
stalemated only if facing a Kc3 and a Knight on one of the squares
b2, c5, b6 that control a4 (the first of these arises at the start of
the stalemate-in-9 shown by Petrosian).

It follows too that each of these four positions is mutual Zugzwang:
the defender get stalemated by force only if on the move.  There are
few enough other Zugzwangs (up to board symmetries) to list them all.
One is the unique losing position of maximal length:

[Title "Mutual Zugzwang"]
[fen "8/8/8/2N5/8/8/8/1k1K4 w - - 0 0"]

Two more are obtained from it by moving the Kings from b1/d1 to
a1/c1 or a2/c2.  Finally, Ka2 against Kc2 and Nb1(b5) are the
shortest mutual Zugwangs.

As Glorfindel suggested, some of these positions are relevant to
the Troitzky ending KNN/KP.  For example, this is a mutual Zugzwang
(in the usual sense of a win BTM and draw WTM), as are each of the
three BTM positions in the main line 1...Kg7 2 Kg5 Kg8 3 Kg6 Kf8 4 Kf6:

[Title "Mutual Zugzwang"]
[fen "8/7k/3N4/1p5K/1N6/8/8/8 w - - 0 0"]
[Title "Mutual Zugzwang"]
[fen "8/7k/3N4/1p5K/1N6/8/8/8 w - - 0 0"]


Is there an online PGN editor for Blank Chess?

Caissa's PGN Editor claims to be what you want.


Is there a site with preparation ideas for opening tabiyas?

The SOS ("Secrets of Opening Surprises") books and articles (in New in Chess magazine) can be good references.  Once in the USATW I was paired up against a 2450 rated player.  I found references with a quick online search that he played the Caro-Khan.  I walked in the bookstore and looked in an SOS book and found a line Kasparov used in blitz a lot.  After 10 minutes of preparation I was armed  to get my well booked opponent out of his element and I won my best game of the tournament.
I've done such things with the Chess Informants a lot including preparation against Yermolinsky in the US Open.  I would say Chess Informant is best if you have the time and money.


What's the etiquette for giving checkmate on board?

This is really a question for fairly low-rated players, who tend to play things out to the bitter end. If you are reasonably strong, the only reason your opponent does not resign earlier is that he thought you played such a good game that he allows you to execute the checkmate (I have done this), or thinks that the final position is beautiful, and saw it coming.

A very good example of the latter is this game between Peter Svidler and Magnus Carlsen at Grenke this past year (2019), where Peter allowed mate on the board. Note the BIG smiles on the faces of both players in this video.

In the end, it is just common sense and human decency: Just be humble, nice, and say "checkmate" politely, and shake hands. Treat the person the way you would want to be treated.

 [Event "Grenke Chess Classic 6th"]
 [Site "Karlsruhe/Baden Baden"]
 [Date "2019.04.28"]
 [Round "8"]
 [White "Svidler, Peter"]
 [Black "Carlsen, Magnus"]
 [Result "0-1"]
 [ECO "B30"]
 [WhiteElo "2735"]
 [BlackElo "2845"]
 [FEN ""]

 1. e4 c5 2. Nf3 Nc6 3. Nc3 e5 4. Bc4 Be7 5. d3 d6 6. Nd2 Nf6 7. Nf1 Nd7 8. Nd5 Nb6 9. Nxb6 axb6 10. c3 O-O 11. Ne3 Bg5 12. O-O Kh8 13. a3 f5 14. Nxf5 Bxc1 15. Rxc1 Bxf5 16. exf5 d5 17. Ba2 Rxf5 18. Qg4 Rf6 19. f4 exf4 20. Qg5 Qf8 21. Qxd5 Rd8 22. Qf3 Ne5 23. Qe4 Ng4 24. Rce1 Ne3 25. Rf2 Re8 26. Qxb7 g5 27. Rfe2 g4 28. Rf2 Qh6 29. Qc7 Ref8 30. h3 gxh3 31. g3 fxg3 32. Rxf6 h2+ 33. Kh1 g2# 0-1


How many attacks can be focused on one point?

Not sure what you mean by "realistic".

Basically you can attack it with 8 knights plus 7 other pieces attacking horizontally/vertically/diagonally, i.e. from each cardinal direction (North, NorthEast, East,...) except for one.

For example:

8/3N1N2/2NBQBN1/3RpR2/2NPK1N1/3N1N2/8/8 w - - 1 1

Notes:

At the start of the game each player has 16 pieces of which two are  bishops of opposite color. That's why one of the bishops will not be able to attack the square and the maximum number is 15.
In the example 7 of the knights are fixed. You can think of (1) using other pieces to attack along the cardinal directions or (2) replace one knight with a piece attacking from f4.
You can move pieces that attack along the cardinal directions further away from the attacked square but this does not help to focus more pieces on the square unless you count batteries double. In any case you are running out of pieces to achieve more than 15 attacks.
It is possible to get 8 knights and two dark squared bishops through pawn promotion. In the example 6 pawns have been promoted to knights and one pawn to a bishop which together with the remaining pawn sums to 8 pawns.


Which chess GUIs support the chess variants Atomic and King of the Hill?

There are three chess variant GUIs supporting both atomic and king of the hill that I am aware of:

PyChess
WinBoard/XBoard
Cutechess

The latter is well suited for automated engine matches and human vs. engine games, but less for game analysis. All three should work fine with the multi-variant Stockfish you downloaded.


Are certain foods or drinks better to consume than others when playing chess?

Here is an article I came across a while ago.

This is probably the key part:

  Chess players should try to have breakfast daily.

  Avoiding “heavy foods” or foods of difficult digestion before games
  must be adopted as a regular habit for chess players. The last “main”
  meal before a game has to be had at least three hours in advance. If a
  player wishes to have something to eat nearer the time of the
  beginning of a competition (one or two hours before, e.g.) he/she
  should choose among fruits (whole ones, fruit salad or juices,
  raisins), cereal bars, pretzels, cookies, low fat yogurt with fruit or
  cereals, sports drinks.

  During the games, it is recommended fluid ingestion, and, if the chess
  player wants it (or when the game becomes long), solid foods. Mineral
  water, fruit juices, tea, coffee, sports drinks, cereal bars, fruits,
  raisins, dry fruits (almonds, e.g.), chocolate, cereal cookies, can be
  chosen. In all cases, moderate quantities should be taken.

  The best strategy to hydration is to drink small quantities at regular
  intervals, instead of greater quantities at a few intervals, and avoid
  being thirsty. The same indication should be followed during board
  training and physical activity. It is also important to begin the
  activity properly hydrated.


I'm new to chess-what should be done here to win the game?

This position is a draw, the game is over. It is not possible for either side to checkmate the other from this position, not even if the side with the bare king would try to help.
The same is true for king and knight vs king. A single knight or bishop without any pawns or other pieces is not enough to win the game.
With king and two knights vs king it is in theory possible to checkmate the other side, but it can't be forced. It's very easy to prevent the checkmate as the defending side. So that is essentially a draw too.
Two bishops, or a bishop and a knight, can force checkmate. It's not easy (especially bishop and knight, it has happened that a grandmaster fails to do it), but it can be done.
It's a better idea to always keep a pawn or two on the board so you can promote one.


Carlsen - Anand, game 6 WCC 2014 -> why Black didn't play 10...Ne4 to try to equalize?

10...Ne4 doesn't help Black preserve the bishop pair. After the surprising move 11.a3!, Black is forced to take the knight on c3 with the bishop and then we reach a position similar to the one in the game, except that Black's knight is on a more vulnerable e4 square than on a safe square like d7. The pawn on c3 cannot be captured without a significant positional loss to Black.

   [FEN "r1bk3r/1p3ppp/p1p1pn2/8/1bP1P3/2N5/PP3PPP/R1B1KB1R w KQ - 0 10"]
   [White "Carlsen"]
   [Black "Anand"]

   1. e5 Ne4 2. a3! Bxc3+ (2... Nxc3?? 3. axb4 Ne4 4. f3! +-) (2... Ba5 3. b4 Nxc3
   4. bxa5+=) 3. bxc3 Kc7 (3... Nxc3? 4. a4! Ne4 5. Be3 f6 6. Bd3 Ng5 7. O-O
   Nf7 8. exf6 gxf6 9. f4 +=) 4. Be3 b6 5. Bd3 Nc5 6. Bxc5 bxc5 7. O-O-O+=


Why does NCM show no progress for Stockfish when each new version has to beat the previous version?

Fishtest tests proposed changes to Stockfish's code with SPRT to determine if they should be accepted. Broadly speaking, there are two types of changes which are tested in this way (non-functional changes do not go through Fishtest): simplifications, and changes which intend to gain strength - elo changes.

The crucial difference here is that simplifications (like the one referenced in the question) are tested for no regression, whereas elo changes are tested for an improvement: SPRT bounds of [0.5, 4.5] are used for elo changes and bounds of [-3, 1] are used for simplifications.

The vast majority of changes to Stockfish recently have been simplifications, and as such they are not expected to increase strength.

For example, the patch in the question is a simplification, and was tested with SPRT bounds [-3.00, 1.00]. The fact that it passed tells us that there is a 95% chance that the change does not lose 3 elo. If the test failed, we would know that there is a 95% chance that the change does not gain 1 elo.

We can't say anything more precise than this, because SPRT stops immediately as soon as there is enough evidence to accept either hypothesis and doesn't attempt to measure the elo change more precisely. Although an elo difference of +2.18 is quoted at STC, all we know is that the lower error bound on the elo gain is >= -3.00.

There is insufficient evidence to say that the change produced an actual elo gain of +2.18, and thus claiming that this simplification gains 2 elo would be misleading.

The small number of elo gaining changes is what results in Stockfish's slow progress at the moment.


What will be the best move in this position?

Almost certainly Bxf5 is a winning move, but it may not be what you want to play. I asked if exf6 was legal. If it is, play it. After Black recaptures play Bg6+ and your attack is just as strong without sacrificing.

In the diagram position, Blacks position is dreadful, probably lost. If you can win without taking risks, why not?

You are not sure if the sacrifice works. That is, you do not trust your analysis. Under those circumstances, should you sacrifice and risk losing? Generally speaking not, if you have a very good position and can see other ways to make progress. Generally yes if you think that your position is bad, and the sacrifice is a last shot.

But perhaps you should sacrifice anyway, just to find out how good your analysis is. Much depends then on the circumstances of the game, Friendly skittles? Last round of tournament? But if you find that it does not work, try to learn something. What did you not see? Why did you not see it? Is there something you should now remember to look for? Did you win, but only because your opponent defended badly? You should look at these things post mortem if you opponent is willing.


What are the best scoring openings in Chess960?

I have found the trickiest part about playing 960 is the opening. So many possibilities! But, since the major pieces are random for every game it is unlikely you'll come across the same setup frequently enough to recognize some opening. So I say ditch trying to create one and stick with tried and true chess opening principles: Control the center, try not to move the same piece twice, limit king exposure.

After playing more games you'll come to find the endgame is familiar which shouldn't be too surprising - the board is still 8x8 after all.


What level of player is Kasparov's MasterClass suited for?

I have seen the materials in the program, and they are for players well below your level of play. I am not sure that they are even for a 1000 player since they are very basic. While he uses positions, they are more about teaching basic terminology and showing various themes, but on a very basic level.

For example, here is one position that you are to find 5 different skewers (Bf3, Bb3, Qg2, Qh1, and Rh5).

 [FEN "6n1/1r6/8/q2k4/8/7R/7Q/3B1K2 w - - 0 1"]

The most “difficult” problems are really no more than two- or three-move tactics like this one.

 [FEN "5rk1/p3P2p/1p4pb/q7/3N4/1P4Pb/PB3Q1P/6KR b - - 0 1"]

 1... Qe1+ 2. Qxe1 Be3+ 3. Qxe3 Rf1#

The vast majority of these problems are very famous, and can be found in other books. He does give book recommendations, but they are ones that have been recommended here many times already, including by myself. He has some practical advice about how to study, but again, it is mostly common sense that may have seen recommended already right here on SEC.

Of course, Kasparov is great, and if you were much weaker, I would have a different opinion, but my verdict is that you probably would be wasting your money.


The one I like is Vega - http://www.vegachess.com/tl/index.php. This is free on Linux. The guy who wrote it is an open source supporter who welcomes feedback and is willing to make changes. He is also an active FIDE arbiter. It is also free on Windows for up to 30 players and 50 euros for unlimited use.

There is a review by an English arbiter here - http://chessarbitersassociation.co.uk/Vega.pdf.


There is nothing wrong with the Petroff and it is still used regularly at the highest levels. If it is less popular than it used to be (and I'd have to check the data before claiming that), then that would likely be because it is usually played when Black is trying to make a draw, and these days the Berlin variation of the Ruy Lopez is the most popular way to try to achieve a draw against 1.e4.


Is it possible to setup DGT Easy+ Gametimer for a 75' for first 30 moves, and 15' for the rest of the game?

My understanding is that this is sold as a budget / beginner's clock which does not support additional periods and so is not suitable for your needs.

You are probably better off springing for the DGT 2010 or DGT XL which I believe are both approved for FIDE competition. The 960 looks a bit flimsy for robust club use although I have no experience using it so it may be tougher than it looks.


The longest possible series of forcing moves that I have cooked up is 3108 moves long, abusing the 50 move rule to its fullest. Throughout the entire sequence, Black has only one legal move as stipulated.
Firstly, we start with this position.
[FEN "1N6/3r4/3p1p2/3B1n2/5b2/4QNPk/PPPPPP1P/R1B1K1nR w Q - 0 1"]

1. Nxg1+ Kg4 2. Qxf4+ Kh5 3. Qxf5+ Kh6 4. Nxd7 Kg7 5. Qxf6+ Kh7 6. Be4+ Kg8 7. Nb6 d5 8. Bxd5+ Kh7 9. Bg2 Kg8

White sets up the Black king's moving zone. It comes with captures to gain 8 extra moves. Next, White makes a pawn move or sacks a piece on g8/h7 every 50 moves. Getting rid of the light-squared bishop, both rooks and knights, and five promoted pieces, from the a2 through e2 pawns, allows for 10 50-move rule resets. Promoting these pawns allows for 5*6=30 more resets. Thus, there are (10+30)*50+8=2008 moves already.
Afterward, this position is reached. During the 49 move intermission before the next reset, White moves the Black king.
[FEN "6k1/8/5Q2/8/8/6P1/5P1P/2B1K3 w - - 0 1"]

1. Bb2 Kh7 2. Ke2 Kg8 3. Qg6+ Kf8 4. Qh7 Ke8 5. Qg7 Kd8 6. Qf7 Kc8 7. Qe7 Kb8 8. Qd7 Ka8 9. Ke1 Kb8 10. Be5+ Ka8 11. Qc6+ Ka7 12. Bc3

Here, White has 4 pieces to sacrifice along with 17 more pawn moves. This allows for 17+4=21 more resets. As such, the total is now (21*50)+2008=3058 moves. There are no more resets after this.
Finally, White merely plays around for 50 more moves. Black then claims a draw by the 50 move rule. It is important to note that sacking the queen actually loses a ply, as then the position is a draw to the "Dead Position" rule. Checkmating and stalemating also lose the essential last Black ply.
[FEN "8/k7/2Q5/8/8/8/8/4K3 w - - 0 1"]

1. Kf1 Kb8 2. Kg1 Ka7 3. Kh1 Kb8 4. Kh2 Ka7 5. Kg2 Kb8 6. Kf2 Ka7 7. Ke2 Kb8 8. Kd2 Ka7 9. Kc2 Kb8 10. Kb2 Ka7 11. Ka2 Kb8 12. Ka3 Ka7 13. Kb3 Kb8 14. Kc3 Ka7 15. Kd3 Kb8 16. Ke3 Ka7 17. Kf3 Kb8 18. Kg3 Ka7 19. Kh3 Kb8 20. Kh4 Ka7 21. Kg4 Kb8 22. Kf4 Ka7 23. Ke4 Kb8 24. Kd4 Ka7 25. Kc4 Kb8 26. Kb4 Ka7 27. Ka4 Kb8 28. Ka5 Ka7 29. Kb5 Kb8 30. Kc5 Ka7 31. Kd5 Kb8 32. Kd6 Ka7 33. Kd7 Kb8 34. Kd8 Ka7 35. Ke8 Kb8 36. Ke7 Ka7 37. Ke6 Kb8 38. Ke5 Ka7 39. Kf5 Kb8 40. Kf6 Ka7 41. Kf7 Kb8 42. Kf8 Ka7 43. Kg8 Kb8 44. Kg7 Ka7 45. Kg6 Kb8 46. Kg5 Ka7 47. Kh5 Kb8 48. Kh6 Ka7 49. Kh7 Kb8 50. Kh8 Ka7

At last, we have our total sequence of 3158+50=3108 forcing moves.


Which piece is least likely to be taken?

I recently looked into that very thing a couple of weeks ago, and found an excellent breakdown on it (just this one, though):

The short answer is that aside from Kings, h2 & h7 are the least likely to be captured pieces (with survival rates claimed to be 73.92% and 72.29%, respectively).

Regarding individual pieces' survival (from a 2,196,968 game database), http://www.quora.com/What-are-the-chances-of-survival-of-individual-chess-pieces-in-average-games/answer/Oliver-Brennan gives a table (and an accompanying graphic) of each piece's respective chance of survival.

While I was at it, I found some data on square usage. I've included the sources below not because square usage relates to your question directly, but because the nature of the two topics is so close that I figured that they might be of interest to you (or future readers).

Using 509 games selected randomly [and analyzed] out of a 567,000 game database, these two URLs give tables of raw events and normalized through-traffic usage of squares, and heat maps of same:

http://sarcasticresonance.wordpress.com/2010/10/05/chess-territorial-2
http://sarcasticresonance.wordpress.com/2010/10/13/random-chess-conquests/

This URL analyzes the moves of 12 Grandmasters' entire careers (separated by white and black, all normalized [no raw counts]), along with some graphs of average-data counts:

http://en.chessbase.com/post/seth-kadish-visualizing-chess
http://en.chessbase.com/post/study-of-square-utilization-and-occupancy

There are also some excellent analyses (per side) of each type-of-piece's square usage at http://philanalytics.blogspot.com/2014/11/chess-analytics-analyzing-championship.html .


The English GM Glenn Flear has coined the phrase "not quite an endgame" or NQE to describe exactly the kind of positions you talk about. He has written a book, "Practical Endgame Play - Beyond the Basics: The Definitive Guide to the Endgames That Really Matter" about these. It covers NQEs where each player has pawns and only two pieces.

Unfortunately it is out of print but you may be able to find it for sale second hand.


How would I train like Bobby Fischer did?

This question may be better suited for Worldbuilding Exchange, but as Bobby's training system you are asking for started at the precise second Bobby met the game at a young age, you will need to:

Return with a time machine to five years old and develop Asperger
disorder.
Buy not only one but a dozen of chess boards.
Develop an uncontrollable obsession with chess as said, forgetting
everything is not chess. Your mother can do those tasks and the
school is totally unnecessary for you. You know modals and how the law
rules, not to enter in troubles not related with chess.
Play millions of games with yourself. Play chess every minute you
don't have to eat, sleep or waste your time with adults. Use those
books only to follow master moves and remaster the games on your
dozen of chess board that have colonized your home (you will need to
convince your mother for that).
Go to the tournaments and destroy all those poor players that read
the text of those chess books you will take a look later to see if
they are correct or not.
Continue enjoying and learning at FIDE circuit your hole life.


Where can I find a list of chess games (or PGN file) for games less than X number of moves (specifically 12 moves)?

pgn-extract can extract games from a pgn file based on the number of moves. The -bu12 flag would give you games of 12 moves and less. There are various databases which you can download for free, see this link

12 moves are really short games, you might want to extend that limit a bit and probably you also want to exclude games that end in draw.

Also IMO  solving general tactics puzzles is very useful for a beginner.


A resource that shows how many ways an opening can be reached?

The point from chubbycantorset's answer about the futility of seeking the number of all ways to reach a position is a good one. Scid has a way of offering more limited (and more practically useful anyway) information than that. Its Opening Report tool allows you to input a position, and then generate a comprehensive statistical report covering games that reached that position (in whatever database you have open). Among the data presented is a tally of how many move-orders were used to reach the position in question that appeared in actual games from the database, as well as a list of the most popular.

For instance, in my big database of millions of games, when I generate a report for the standard Sicilian Scheveningen position

[fen "rnbqkb1r/pp3ppp/3ppn2/8/3NP3/2N5/PPP2PPP/R1BQKB1R w KQkq - 0 1"]

part of the information I receive is as follows, where the numbers in parentheses indicate how many games feature the move-order in question:

There were 82 move orders reaching this position. The top 8 are:
  1:  1. e4  c5 2. Nf3  e6 3. d4  cxd4 4. Nxd4  Nf6 5. Nc3  d6 (18538)
  2:  1. e4  c5 2. Nf3  d6 3. d4  cxd4 4. Nxd4  Nf6 5. Nc3  e6 (11028)
  3:  1. e4  c5 2. Nf3  d6 3. d4  Nf6 4. Nc3  cxd4 5. Nxd4  e6 (646)
  4:  1. e4  c5 2. Nf3  e6 3. Nc3  d6 4. d4  cxd4 5. Nxd4  Nf6 (597)
  5:  1. e4  c5 2. Nc3  e6 3. Nf3  d6 4. d4  cxd4 5. Nxd4  Nf6 (258)
  6:  1. e4  c5 2. Nf3  e6 3. d4  cxd4 4. Nxd4  d6 5. Nc3  Nf6 (144)
  7:  1. e4  e6 2. d4  c5 3. Nf3  cxd4 4. Nxd4  Nf6 5. Nc3  d6 (117)
  8:  1. e4  c5 2. Nf3  d6 3. Nc3  Nf6 4. d4  cxd4 5. Nxd4  e6 (92)


Am I actually playing against a 1425 rated player?

I don't know if the engine was really playing at 1400+, but it was quite weak. 1400+ rating sounds fair to me.

Please note:

Shredder is not the iPhone app you mention. It's rating system is not the same as what Shredder is using.
The iOS app you mention is definitely under-rated. I tried it several times, I know.


Should I practice openings of a famous player if I want to play like them?

The openings are a good start; they give players like Tal the opportunities for combinatorial wizardry.  But it's a lot to ask of oneself, to play like Mikhail Tal.

They say that Tal played a lot of speculative sacrifices. That is, he felt the sacrifice was sound enough, but he didn't calculate it out to be sure.  Maybe.  Be advised, however, that the man didn't get to be World Champion by guessing.  He could calculate.

Unlike mere mortals, Tal's brain could cash the checks his fingers wrote.

If you want to play like him then develop your tactics specifically where unbalanced positions are concerned, look for opportunities, and don't be afraid to lose.  You'll have to be just as fierce, fearless, and skilled, relative to your peers.

NOTE - remember, what matters is that you win (or lose) the game well.  It does not matter if someone uses some computer to refute your moves after the fact.  The only refutation that matters is the one your opponent finds over the board.


The knight on c3 is the difference.  In the second position, White can exploit superior development by quickly opening the centre with c4.  It's not easy for Black to arrange castling.


Why can't the king castle in this position?

Executive summary:

Black actually can castle, but if he does castle he will lose the knight and the game (due to material loss).

Detailed answer:

Black and White have equal material.

The black knight is protected by two pieces: the king and the queen.
The black knight is attacked  by two pieces: the queen and rook.

If the king castles, the knight will be protected only by the queen, and White will be able to win the knight which will lead to a big material advantage: a knight, which is worth about 3 points.

"Castle by hand" (meaning moving the king and the rook over several turns until they reach a castle position) will allow Black to keep protecting the knight. (E.g. By moving the king to F7 to protect the knight, followed by a rook to E8, etc.)


What is the best way to get games for the multiple editions of The Week In Chess?

Here is your requested zip:  2013_TWIC.zip

I created a command script for this. See attached. I assumed you are running
Windows, but the script is easily adapted to other OSes.

For downloading, it uses curl. You can get that at http://curl.haxx.se/download.html, and
for Windows, I recommend the msi installer.

For unzipping, I used Java's Jar tool, which is free. But use whatever you
prefer.

When running the script, run dos shell as Administrator in Win8 or Win7.
At the end of the script it puts all PGNs into one large PGN file called 2013_TWIC.pgn
HTH.

Click: Script to get 2013 TWIC PGN files


Is the expression 'fixing pawns' or 'fixed pawns' - a proper term to describe blockaded pawns?

Often pawns are "fixed", it's more than them just being blockaded.  For example assume Black's pawns are on b7 and a6.  If White pushes his a-pawn to a5, he is fixing the b-pawn on the b7 square, since it's backwards and can't move.  However, in this example no one would really think White's also "fixing" the a6 pawn, even though it's blockaded.

But then you have another case like the following: suppose Black has an isolated pawn on c5.  If White pushes his c-pawn to c4, many would say he is fixing the weak c5 pawn, so that it can be easily attacked.

But assume Black had two extra pawns on d6 and e7, forming a pawn chain from e7 to c5.  If White played c4, I doubt there would be many that considered White was "fixing" the c5 pawn.

So, when someone says "fix" they are most often talking about when you keep one of your opponent's weak pawns from moving.  This is just arbitrary terminology though, and I don't think saying a blockaded strong pawn is "fixed" is wrong.


Generally speaking, it's a draw. Most pawnless endgames are drawn, unless one side has a material advantage of more than a minor piece. Either side can win if there are short-term tactics. To check the outcome of a position, you can use an online tablebase. In particular, it's nice to view the longest wins for either side, which are (according to this page) are
[FEN "k2q4/7R/8/8/8/8/8/2K3R1 w - - 0 1"]

(White to move, mate in 29)
and
[FEN "4r3/8/5Q2/8/5r2/1k6/8/1K6 w - - 0 1"]

(White to move, mate in 49)


There's no magic number, especially since your definition of "improve" could be different from anyone else's.

I play about 5-10 rapid games per day, and have a few ongoing correspondence games at any time. Then again, I'm not a beginner, and if you're truly a beginner I'd say keep playing games as long as you're enjoying it. No need to keep grinding out more games if you're not having fun. For one, you'll not learn as much, and what's the point of playing a game if you're not enjoying it? Also there's no reason to stop if you've hit the day's "magic number" of games.

Most important is analyzing your games after the fact. If you're reading a chess book (i.e. How to Reassess Your Chess, etc), after you're done with a game go back through the moves and see if you're following the guidelines the author laid down. See what you could've done better. See what you did well.

Saying you'll play 100 games a day to get better won't likely make you better if you're not enjoying it, and aren't following a study plan.


Is a Finite State Machine a good way to model chess?

Yes, I think so.

You'd have all possible board positions as states (so lots of states, but finite).
The starting position as an initial state. Legal moves as links between the states (so the "alphabet" would consist of all possible moves). Positions that end the game like checkmate, stalemate and dead positions as accepting states.

In the end you'd get the set of all possible chess games as the language that is accepted by the machine.

How you'd work this out formally with things like illegal moves, the 50- and 75- move rules, describing a list of legal moves formally et cetera are left as exercises for the reader.

Draw offers, and games ending in other external ways like a mobile phone going off should probably be left out.


Can GMs use computers to beat their opponents?

You pretty much described modern day preparation...

This is exactly what GMs are doing, except that they also try to add some of their own creativity into the process. Nevertheless, the majority of the heavy lifting is done by engines.

However, the process doesn't come close to guaranteeing a win due to the sheer number of possibilities. For example, assume that on each of your opponent's moves, he has 3 good moves to choose from. This means:

After his 1st move, you have to prepare for 3 outcomes.
After his 2nd move, you have to prepare for 9 outcomes (since each of the 3 outcomes for his 1st move then have 3 follow up outcomes when its his turn on the 2nd move).
After his 3rd move, you have to prepare for 27 outcomes.
4th move ==> 81 outcomes.
5th move ==> 243 outcomes.
6th move ==> 729 outcomes.
7th move ==> 2187 outcomes.

You can see where this is going, and this is based on the generous assumption that your opponent only has 3 acceptable choices. After the early stages of the opening, this number is often much higher.

But going off 3 choices, the horrible function for the approx. number of reasonable outcomes is f(x) = 3^x, where x is number of moves your opponent has made. However, GMs often still manage to prepare for 20 moves, which means their opponent has moved 10 times. 3^10 = 59,049. So GMs are clearly very clever at predicting what's going to happen, and have excellent memories, but even this can barely get to 20 moves.


What is the effect of aging on chess ability?

According to this study chess grandmasters peak at age 31.4.

This study confuses the hell out of me, but there is one sensible chart at page 20, that seems to indicate that you can still improve a little bit in your thirties and generally hold your playing level into your mid-forties. After that the decline becomes noticable.

The slight discrepancy between these two studies is easily explained by the fact that the first only looks at grandmasters, whereas the second examines more than 40,000 players. In fact I would assume that the very top players peak even earlier these days.

I found a very good chess.com article about this topic. This guy analysed more than 71,000 players and found a rating peak in the late twenties. Until you are eighty you'll lose 200 Elo points on average, which really isn't all that much.


What checkmates are appropriate for 7 year old kids?

The approach I use (also with older kids) is that the process of mating involves putting the king in jail and making the walls smaller and smaller ...

For something like smothered mate it is the pieces on the king's own side which build the walls! But when there is not much material left on the board you have to build the walls with your pieces. You can then show them the kind of walls the queen, one rook and then two rooks make. I would also show the wall that one king makes for the other, even though this is only 3 squares long. It comes in handy for KRvK. Of course every wall (apart from the queen wall because the king can't approach the queen) has at least one hole in it where the piece stands.

Once you have this principle established it is easier to teach them the KQvK, KRRvK, KRvK endgame mates. With the ideas behind the "build a prison wall and make it smaller" I believe you can even introduce the KBBvK endgame to young kids although they likely won't succeed most of the time. However it introduces some more interesting ways of handling the two bishops which may help them in the middlegame and I think is still well worth while.


Computers are really stupid, they can't evaluate a position that contains exchange threats.  When the program reaches the expected depth and there are exchanges present in the position, the computer performs a Static Exchange Evaluation, which is hard to program correctly, or it extends the search depth until the exchanges and other factors are eliminated.


Four player chess (team): is there some opening theory written somewhere?

I doubt there is any existing theory for four player chess, because it is not widely played or analyzed.  I'm not sure if there even exists any serious investigation of the overall strategy or tactics of this variant, as it is mostly a novelty game played casually.  It's pointless to analyze openings when even the basic strategies of a game are largely unknown.

I also suspect that the game itself is not really well suited to opening analysis in general, due to the increased size of the board and number of pieces.  This also makes writing an engine significantly more difficult.


I think overtheboard is mostly right, especially because your quotes seem to have this gist, but there is another aspect to playing on autopilot in chess, more often referred to as "playing by hand", i.e. without using you head.

If you reach a certain level in chess, in almost all positions a "typical" move represents itself to you, not necessarily the best move, but with high probability a decent move. This phenomenon is closely connected to the term priyome, which refers to standard positional responses and methods, that somebody with a certain amount of chess culture just knows.

So if somebody talks about playing on autopilot or playing by hand, he might just mean choosing natural strong moves without looking deeply into the position. Often this is enough to beat weaker players and it can be done in all kinds of positions, not just in easily winning ones or in forcing lines.


The Giuoco Piano after 4.c3 Nf6 5. d4 exd4 6. e5

(Answering my own question since I got some help from an expert)

Bb3 is a weak move, since the game will soon be focused around the d4-square. White should have played 7. Bb5, pinning the knight. Playing Bb3 instead yields an inferior version of what happens next.

e4 is the best post for the knight - it's a central square, and it's defended as well. Now white has to play 8. cxd4 or he'll be down a pawn. Black responds with Bb4+. The aim of this move is to force a minor piece to d2, which interferes with the queen defending d4. After 8...Bb4+ 9. Bd2 Nxd2 10. Nbxd2, black plays Bg4 pinning the knight and making it very difficult for white to defend the d4-pawn. If white plays 9. Nbd2 instead black can just continue with Bg4 and leave the c1-bishop to stew.

Now white's position starts to get unpleasant. In addition to Nxd4, black threatens 11...Bxf3, ruining white's pawn structure (11. a3? Bxf3 12. Qxf3? Bxd2+ 13. Kxd2 Nxd4 wins a pawn since 14. Qxd5?? Nxb3+ wins the queen). White has to play 11. Ba4, which shows why 7. Bb5 occupying the diagonal sooner was the correct move. Black's position is still preferable: white's knights are pinned, and after 11...O-O 12. Bxc6 (forced) bxc6, black is ready to play ...c5 contesting the center. In the final analysis position below, black has more space, the initiative, and the bishop pair.

[FEN ""]
     1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d4 exd4 6. e5 d5 7. Bb3?! Ne4 8. cxd4 Bb4+ 9. Bd2 (9. Nbd2? Bg4) Nxd2 10. Nbxd2 Bg4 11. Ba4 (11. a3? Bxf3 12. gxf3 Ba5) O-O 12. Bxc6 bxc6 13. O-O c5

As to what happens after 7. Bb5 ... that's another question entirely =)


The Bong-Cloud opening is a joke opening that is meant to give your opponent a chance, and also it is meant to show contempt for your opponent. You play it because you think you are much stronger than they are. It is, obviously, not a good opening.
GM Hikaru Nakamura is one of the jokesters, who plays this from time to time. There are multiple YouTube videos showing him playing this. Here is one.
P.S. Another chess.com joke you might hear is a reference to the the "Botez Gambit". It is a joke about WFM Alexandra Botez, who drops her queen a lot.
 [FEN ""]

 1. e4 e5 2. Ke2? {The Bong-Cloud!}


Stalemating the opponent in order to not lose

It's possible to build a bit on magd's answer. Consider the following position.

 [Title "White to move"]
 [SetUp "1"]
 [FEN "8/8/8/8/8/1N6/pk1K4/8 w - - 0 1"]

 1. Na1! Kxa1 2. Kc1

The only way to draw is 1. Na1! Kxa1 2.Kc1 (or 2. Kc2) stalemate. I think there are some nice studies with this theme, but I can't find them right now.


Analysis of a position of a low rated player in order to improve

The first thing that comes to mind is that your king-side has been weakened quite a bit, but thankfully, it is your move. If it were black to move, you would be all but lost after 1...Nxe4 2. dxe4 Nc6, and Rd8 next since your queen would be forced away from your king, and it would likely perish to an attack.

 [FEN "rn2kb1r/ppp2ppp/5n2/7q/4NPb1/3P1N2/PPP1B2P/R1BQK2R b KQkq - 0 1"]

 1...Nxe4 2. dxe4 Nc6 3. null Rd8

In this position, even with you having the first move, I would still say that the position is more difficult for you. If you let it think for a moment, Stockfish rates it as slightly better for you, but if you do not play the EXACT best moves, it is easy to end up with black better. That is generally a sign that your position is not so great in practice since we are not computers.

Especially in the opening, you should post the moves that led up to this because I would say that you have made mistakes, and it is probably more important to correct those than worry about a position that is already tricky to play.

In this position, you have a few moves that do not lose immediately: Ng3, Be3, and Nf6+. The computer likes Ng3 the best and I will give that as the primary variation. The computer is not 100% sure about this variation, and often changes its evaluation on what is the best move for both sides as you go along, but you can see that many of the moves are not human. In cases like that, you are likely to play moves that are worse because you want to play positions that are easier to find good moves for you, and that make it difficult for your opponent to find them. Tal made a living off this principle.

 [FEN "rn2kb1r/ppp2ppp/5n2/7q/4NPb1/3P1N2/PPP1B2P/R1BQK2R w KQkq - 0 1"]

 1. Ng3 Qa5+ (1... Qg6 $4 2. f5 Bxf5 3. Nh4) (1... Qh6 2. f5 Qh3 3. Bf1 Bxf3 4. Qxf3 Qh4 5. Qxb7 $18) 2. Bd2 Qb6 3. Ng5 Bd7 4. Bh5 Nxh5 5. Qxh5 g6 6. Qe2+ Be7 7. Bc3 O-O 8. Qe5 f6 9. Qd5+ Kh8 10. O-O-O {And finally, it is clear that white is much better}


Here are a few reasons one may take up the defense:

Despite having the Queen kicked by the Knight, the Queen is in no real danger of being trapped, its most common escape locations being to a5 and d6.
Black's pawn structure is solid, in similar ways to the Caro-Kann.
The number of lines Black needs to know are fairly limited, this makes it an easy defense to get into.
It's not played very often, so the Black player will likely have more familiarity with the positions than White.
Black is able to develop all the pieces and castle in relative safety; notable is the ability to develop with the Bishop on c8 before ...e6 is played.


How can I use pgn-extract to remove a game from a pgn file when there is an illegal move?

pgn-extract will do exactly that if you give it an input file and say where you want the correct games to go. For instance:

pgn-extract --output clean.pgn games.pgn

will put only the valid games from games.pgn into clean.pgn, reporting any errors on standard output. If you want to have a record of the errors then you can use the -l flag to specify a log file; e.g.:

pgn-extract --output clean.pgn -lissues.txt games.pgn

There are lots of additional options/flags described in the documentation.

Disclosure: I am the author of pgn-extract.


Can you say anything if you see cheating at another board?

You should not address player B directly, it is forbidden to talk to him about his game (it is actually forbidden to talk to him at all, but the spirit of the law is to prevent conversations about the game).

However, you can (and should) tell the arbiter about what you have seen, and the arbiter will decide on the appropriate action.


Running down the opponent's clock on purpose

That's how it goes. Time management is an important part of tournament chess play.


This is actually quite a sensible question and it isn't about the English word 'counter' as JiK suggests, but about the English word 'play'. ;-)

To have 'play' in a position basically means that you are able to create threats. The possibility to create threats isn't really linked to how complicated a position is. But a position in which only one player can create threats usually isn't very complicated.
So there are positions with counter play that aren't very complicated, but going for counter play often complicates a position.

'counter' just means that your opponent had all the play before and only now you start to strike back.
You could say that 'counter play' is a defensive technique. You may not be able to parry your opponents threats, but by creating counter threats you can dissuade him from executing his threats.

I'll try to come up with some endgame example later …

No endgame, but very recent and a really nice fight - Adams-Caruana:

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5
7. Bb3 O-O 8. d3 d6 9. c3 Na5 10. Bc2 c5 11. Nbd2 Nc6 12. Nf1
h6 13. Ne3 Re8 14. a4 Be6 15. h3 Bf8 16. Nh2 b4 17. Bb3 Rb8
18. Bc4 bxc3 19. bxc3 d5 20. Bxa6 Qa5 21. c4 Qxa6 22. exd5
Bxd5 23. cxd5 Nb4 24. Ra3 Nfxd5 25. Neg4 f6 26. Nf1 Rbd8
27. Ng3 c4 28. Nxh6+ gxh6 29. Qg4+ Kh8 30. dxc4 Ne7 31. Qh5
Ng8 32. Nf5 Qb7 33. Rg3 Qh7 34. Nh4 Ne7 35. Ba3 Nbc6 36. Kh2
Bg7 37. Bxe7 Nxe7 38. Rd1 Qg8 39. Rb1 Rb8 40. Rd1 Red8 41. c5
Rxd1 42. Qxd1 Rb4 43. Qd7 Rxh4 44. Qxe7 Rd4 45. c6 Qf8 46. Qb7
Rb4 47. Qd7 Rd4 48. Qb7 Rb4 49. Rc3 f5 50. Qd7 Rd4 51. Qe6 Rd6
52. Qxd6 Qxd6 53. c7 e4+ 54. g3 Bxc3 55. c8=Q+ Kh7 56. Qxc3 f4
57. gxf4 Qxf4+ 58. Qg3 Qd2 59. Qc7+ Kg6 60. Qb6+ Kh7 61. Qb7+
Kh8 62. Qa8+ Kg7 63. Qxe4 Kf6 64. Qf3+ Kg6 65. Kg2 Qa2
66. Qe4+ Kf6 67. Qf4+ Kg6 68. Qd6+ Kg7 69. Qe5+ Kh7 70. a5
Qg8+ 71. Kh2 Qf7 72. Qe4+ Kg7 73. a6 1-0

If you look at the position after 27.Ng3 it looks pretty depressing for white. Black has all the play, d3 is weak and white is lacking space. But 27…c4 gave Adams the possibility to create counter play against the black king, by sacrificing his knight on h6.

Concerning wisdom: I'm not sure you will have much luck searching for heuristics. Counter play and prophylaxis mostly rely on accurate calculation and maybe some alertness for tactical possibilities. Apart from that it is just an aspect of your positional feel for the game, to know how much play you can allow your opponent and when you have to throw a spanner into his works no matter what the cost.


Open source Chess engines under MIT license?

Crafty
Arasan

I don't recommend Pulse or NG-Play in the other answer as they're no longer maintained. The three engines I cited are still very active.


I am going to make a few suggestions on reading material.

Pay a visit to Dan Heisman's column at Chess Cafe called the Novice Nook. Pay special attention to what he writes on the topic of Real Chess (article 1 and article two).

Focus as much as you can on this "Real Chess" idea in your studies and games. Always remember you will play the way you train. Therefore put a lot of training into proper over-the-board analysis. A book like Practical Chess Exercises can be useful for this as it has a mixture of tactical and positional positions so you are never certain if you should be looking for a forced sequence or a positional idea.

Honestly I would not spend a ton of time studying the openings. But software like Chess Position Trainer can help you a lot. As far as which ones, stick with the ones you enjoyed in the past and learn new ones that you see in your studies.

For literature I think Ludek Pachman's Modern Chess Strategy is probably one of the first books you should read. I also really like Silman's Complete Endgame Course: From Beginner To Master for fundamental endgame theory that is highly practical.


Understanding Kramnik's play in game 1 of Candidates 2018

The short answer is: white's making it difficult for black to challenge the center with their central pawns. But that's not really revealing much, so let us dig deeper into this beautiful middlegame.

The rook doubling is in fact part of a grander scheme that Kramnik has in mind. Once black commits to d6, Kramnik targets a very concrete objective:

To undermine black's control over the d5 square in order to establish a centralised knight on d5. Ultimately, the plan stems from the asymmetry between the light square control provided by white's center compared to black's central pawn setup (d6-e7). The plan is quite simple in appearance but becomes rather involved once we try to see how it ought to be executed.

Let's now visually unravel the whole thought process behind this plan, but given the question appears to be asked at a basic level, I'll skip certain concrete (tactical) details and only cover the gist of the involved strategic ideas.

So the question is now re-iterated to: How can we establish a knight on d5 without allowing black to easily prevent or trade on d5? and if a trade is to happen on d5, we definitely don't want to have to re-capture with a pawn, which would block a useful central square and potentially gift black a target on d5. Alternatively, you can reformulate the question: How can we turn the d5 square into a safe knight outpost?

Black's control over d5:

Kramnik's surgical strategy:

Left: Reroute knights to d5| Mid: pin the f6 knight | Right: Pressure d6

Left: We need both knights in range of d5 as otherwise in principle black could trade the light square bishop for the knight landing on d5 and white would have to recapture with the pawn, which is exactly what we want to avoid as explained earlier.
Mid: One of the best defenders of d5 is the well placed knight on f6, and one way to undermine its defense is to pin the knight by creating a battery along the long diagonal against the fianchetto'ed bishop.
Right: If black is able to play e6 without any drawbacks, then they'll have permanently secured control over d5, therefore, by pressurizing the d6 pawn white is making it more difficult for black to play e6 as it would weaken an already targeted d6 pawn.

Notice that in contrast to d5, the b5 square is not as good a post for a knight since not only it is not a central square (knights are strongest when centralised), it is also a square that is quite easy to cover for black as a6 is playable in most cases (unlike e6) thanks to the closed b-file which makes it difficult for b6 to be put under pressure (and thus stop a6).

In summary, with black's 11...d6 commitment, white sets out to establish a well centralised knight on d5, which was harmoniously achieved on move 22.Ncd5:

 ---->

It must be noted that the knight post on d5 is not permanent, but for as long as the knight can stand centralised without black being able to reciprocate a similar level of minor-piece-activity, white stands favourable - with constant pressure on key squares in black's structure (c7, e7, f6...). That's why Grischuk has tried to counter white's threats by mounting a direct attack on white's king with the rook lift.

Although there's a slight positional edge for white in that final position after Ncd5, it's by no means winning for white, in fact it's just about to get ignited [*], but it is a prime example of Kramnik's positional approach to the game, he always plays with a clear plan in mind, enabled not only by his great strategic intuition for exploiting/spotting weaknesses and calculation capabilities, but also by his tirelessness and resourcefulness in finding ways to improve his pieces. His games cannot be recommended enough to be studied, his purposeful play-style is a unique portrayal of harmony in chess.

[*]: there are many tactical lines that can ensue from the reached position, e.g., Nxd5 Bxd5 Bxb2 Qxb2 Bxd5 Nxd5 and neither Nb6 nor Nf6 are immediately playable (try to figure out for yourself as an exercise). Or Nxd5 Bxd5 Bxb2 Qxb2 Nf6 Bxa8 Qxa8 Rxd6 exd6 Qxf6 (with interesting positional compensation). Or Ne5 Be2 Ne4 ... which is what happened in the game.


Rooks are more suitable for open games where there are open lines. Knight are better for more closed games. Knights have the benefit of jumping over other pieces and rooks have the ability to move quickly whereas knights move very slowly.

Also, remember that you can't checkmate with just a Knight and King, so Rooks are probably more powerful in the endgame especially when the board is wide open.


I have some partial statistics for the question, from the Million Base 1.74 database, a collection of 1742057 games. 77218 of these games (4.4%) feature at least one promotion.

I counted 49970 promotions for white (54% of all promotions) and 42519 for black (46%). Here are the destination square statistics (meaning there is no track of the actual initial pawn square, because that statistic is a lot more difficult to gather), for all games and depending on the type of castling:

White         a8    b8    c8    d8    e8    f8    g8    h8
all         15.8% 14.2% 13.8% 14.8% 11.5% 11.3%  8.7%  9.8%
with O-O    15.8% 14.3% 13.9% 15.9% 11.8% 11.2%  8.1%  9.1%
with O-O-O  17.1% 14.7% 14.2% 10.7%  9.9% 11.7% 10.8% 11.0%

Black         a1    b1    c1    d1    e1    f1    g1    h1
all         16.0% 14.7% 14.4% 12.6% 11.8% 11.3%  9.0% 10.1%
with O-O    15.9% 14.8% 14.3% 12.9% 11.9% 11.3%  8.7% 10.0%
with O-O-O  13.5% 10.7% 10.9%  9.7% 12.4% 14.0% 14.0% 14.8%

A few observations:

queenside promotions seem significantly more common than kingside promotions
column statistics are quite consistent between black and white (except maybe when black castles long)
castling long increases the odds of a promotion happening kingside


To answer your question:

Experience has shown that it is a good idea in the opening phase of the game to:

develop minor pieces (bishop/knight) quickly
and to occupy the centre (squares e4, d4, e5, d5 and thereabout) with pawns and/or to attack the centre with minor pieces

In this sense Nf3 is the better (and by far more popular) move. It attacks central squares (d4 and e5) and thereby prevents black from occupying the center with e5 immediately and potentially could also support a white pawn push to d4.

Na3 on the other hand does little to get hold of the center and in addition (as with any knight on the rim), it has fewer squares to go to: 4 instead of 8.

Occupying the center is important among others because it can:

limit the space of your opponent
allow pieces stationed around there to quickly reach other parts of the board as needed

For a novice player the first move(s) don't matter. It is highly unlikely that you win/lose a game because of the difference between 1. Nf3 and 1. Na3, rather because of some tactics later on. That's why it is recommend for beginners to focus on tactics first.


What are the reasons why I should not try to take a Knight with my Bishop if it'll result in doubled pawns?

This is a variation that was played fairly frequently, but it has been more or less worked out to a draw, so it is less common at the top levels now.
The Ruy Lopez is a very concrete opening, and the capture on c6 has to be carefully considered as it relates to the exact position.
In terms of opening principles, you're giving up a bishop for a knight in an open position.  If you could take the pawn on e5, it might be good, but the pawn is protected via the tactical shot 5.Nxe5? Qd4! when white has basically given up the two bishops for very little compensation in a wide open position.
Another downside to Bxc6 is that the black's light square bishop is developed by dxc6, allowing it to come to g4 without waste of time.  Indeed, one of the most critical lines continues 5. O-O Bg4 6. h3 h5 when black is offering a piece for attacking chances along the h file.
With all of that said, this is a very common motif in the Ruy Lopez (Bxc6).  The pawn structure after d4 and exd4 is very good for white.  If all of the pieces were traded off, white would win the king and pawn endgame by making a passed pawn on the kingside and black cannot make a passed pawn on the queenside.
There are also many cases when spoiling your opponent's pawn structure is very good.  For example, if black has castled kingside, and a bishop can take on f6 and force ...gxf6, this is almost always good for white.  The king becomes very exposed with the g file open.  In the Spanish Four Knights, one player or the other will very frequently take on c6 or c3.


Learning to play better chess by itself is a part of reinforcement machine learning (temporal difference learning). A simple google will give you some academic papers. My recommended papers (that I've read myself):

KnightCap
NeuroChess
Giraffe

While the programs are different. They share the similar idea:

The idea is like this:

Come up with an evaluation function that you think appropriate
Implement a search algorithm (mini-max, nega-max etc)
Initialise the weights in the evaluation function. The weights would be your features
Play a game against itself
Record the result of the game and compute the error.
Apply the following TD-Leaf equation to change the weights

Play more games until you believe your values have converged

The equation updates the weight vector by the gradient, scaled by a constant (learning rate). The errors would be the temporal difference (d(t)) in the equation. They would need to be added for all moves until the end of game, scaled by the distance from t. Please google TD-Leaf if you want to know more.

While there have been some serious attempts at applying the TD-Leaf algorithm, none of which was strong enough to compete with Komodo and Stockfish. I think that's because:

Lack of determination. The authors wrote their TD-Leaf chess engines for their research. Once that was done, they moved on to something else, something much more profitable for them. For example, the NeuroChess program was written by a very well-known AI export. He works for Google and I think Google has more challenging task for him.
Weak search algorithm
Not challenging anymore. A human tuning chess engine can easily defeat the best grandmaster. Why would we waste time and resources to further improve it? Why not spend the money on Go, where the best human player has yet to be beaten?

Some remarks:

While it's possible to train a model from random weights, we don't want to do this because it would lead to extremely long training times. We can give starting values with some human-knowledge, or bootstrapping (read the Giraffe paper for details).


Would the best mobile phone chess app be a favorite in a match against Carlsen?

Magnus Carlsen was beaten by his own chess app, but it wasn't a serious game and he did it for a presentation. I don't think that game meant anything. While I don't have data for the World Champion, I'm quite certain one of the former world women chess champions was overwhelmed by my iPhone mobile chess app. I also got similar reports for grandmaster over FIDE 2600.

To appreciate the power of a mobile chess app, we should review the match between Deep Fritz and Kramnik in 2006. According to the wikipedia, the machine had two Intel Core 2 Duo CPUs. Wikipedia states the CPUs have clock speed of 1.06 GHz to 3.33 GHz. The wikipedia also states the latest Apple A8 chip has clock speed of 1.1 GHz to 1.4 GHz. Please keep in mind clock speed is a very rough guide to performance. Anyway, the Apple iPhone is at least competitive to an Intel Core 2 Duo in terms of raw clock speed. It has been reported the older Apple A7 chip has performance close to desktop. You should be assured the latest Apple A8 chip can give any grandmaster a challenge.

Let's take a look at the unofficial rating list for Android chess engines. While the rating scale is not related to the FIDE rating, it's hard to believe Carlsen will have an easy time against Komodo 9 on Galaxy 6, which has a rating of 3239 in the list.

Apart from the hardware, the engine algorithm has improved dramatically since Kramnik's match. We now have access to everything that a super chess engine should do; just look at the source code of Stockfish. Back in 2006 when the match was played, all of the strongest engines were closed source.

The version that Kramnik played was a 32 bits engine. This is a bit embarrassing in today's standard. The stronger mobile chess apps (including my own) are now 64 bits.

We don't have any concrete data because no grandmaster has played a serious match against a mobile phone (because there is no money involved). What we can do is infer from historical data, software improvement and rating list. I am confident Carlsen will be beaten by the strongest mobile chess app on the app store.

Finally, while Carlsen is the best player against human players, he's probably not the best player against computers. For example, Carlsen's usually trick; pushing hard in a drawn endgame would not work against a computer. Computer engine will never blunder and will never crack.


Is there any opening line which is downright catastrophic?

If you mean "Is there any first move for white which is catastrophic?" then the answer is "No". There are first moves for white which look bad. Na3, Nh3 and f3 would be my candidates but they are not catastrophic.

Na3 could be followed up by moves like b3, c4, Nc2, Bb2, for example, to get a playable position. Perhaps not the best use of first move advantage but certainly not catastrophic.

The problem for black when white makes a "bad" first move is to try and steer the opening into one where the "bad" move is really a bad move in the context of that opening or at least irrelevant so that white's first move advantage has gone.

White's contrasting problem is to try and steer the opening towards one where the "bad" move becomes good. For instance, after 1.h4 if white can steer black into fianchettoing his king's bishop and castling kingside then 1.h4 could become a strong threatening move.

If by "opening line" you mean a sequence of moves then, yes, there are catastrophic lines and yes, they do often have names. The most famous is  probably Scholar's Mate:

[FEN ""]
[Event "Scholar's Mate"]

1. e4 e5 2. Qh5 Nc6 3. Bc4 Nf6?? 4. Qxf7#

The shortest possible mate and so the most catastrophic is Fool's Mate:

[FEN ""]
[Event "Fool's Mate"]

1. f3 e5 2. g4?? Qh4#


What happens in this multiboard scenario?

That's a trick once performed by Derren Brown.

This article calls it "mirroring technique" and claims it is more than 25 years old, but I don't think this is a very well known term.  If you are interested in more information about this trick you should probably google "Derren Brown Chess".


From Quora: What was Bobby Fischer's IQ? (2018):

  Short answer: In 1958, when Fischer sat a Stanford-Binet test at the age of 15, his score was 180-187. But in today’s terms, Bobby Fischer’s IQ should be 148–155 on the Fifth edition of the Stanford-Binet test, and 150-160 on the WISC-V/WAIS-IV tests administered by Mensa.

The only reference provided for the 180-187 score is a link to the webpage The Mind of Bobby Fischer by Frank Brady where it states that

  In previous writings I have cited Fischer's I.Q. as in the range of 180, a very high genius. My source of information is impeccable: a highly regarded political scientist who coincidentally happened to be working in the grade adviser's office at Erasmus Hall - Bobby Fischer's high school in Brooklyn - at the time Fischer was a student there. He had the opportunity to study Fischer's personal records and there is no reason to believe his figure is inaccurate. Some critics have claimed that other teachers at Erasmus Hall at that time remember the figure to be much lower; but who the teachers are and what figures they remember have never been made clear.

The given rationales for the deflation of the score per today's standard are the Flynn effect based on a large meta-analysis that every year general intelligence increases by 1/3 IQ points, and the revised editions of the S-B test.


Kasparov's Immortal Game. Flawed? 24...Kb6! Suggest an improvement for White

The question therefore is, where did Kasparov misplay the position?

No, he did not. All the lines give Black equal chances, no matter what move White chose to play.

  How did he lose his small positional advantage.

He did not lose advantage because there was none in the first place. White position just looks "prettier". He can not stop the freeing d5 break, which means that Black will eventually equalize.

  Where is the improvement for White?

At this point I see no improvement, but maybe some super computer or creative GM can find one. Time will tell.

  Or is White's positional advantage an illusion?

White has healthier pawn structure, but you do not consider Black's dynamic resources such as development advantage and active piece placement. They counterbalance White's healthier pawn structure.

After Black gets d5 break it all depends if White can punish Black for pushing too many pawns forward. To do that, he need an endgame with better pieces but that will never happen with proper play because Black has better posted and more active pieces.

White does not have an advantage, but his position is "prettier" due to the healthier pawn structure. Again I point out that black has better piece placement, and can liquidate the d6 backward pawn after which things are unclear.

  Is the position objectively equal or even better for Black?

I will quote Mr.Kasparov himself from Chess Informant 74 :

[fen "2kr3r/1b2qp1p/pn1p1npQ/1pp5/4P3/PNN2P2/1PP3PP/1K1R1B1R w - - 2 16"]

1.Na5 ( 1.a4?! b4 2.a5 bxc3 3.axb6 Nd7=/+ ) 1...d5 2.Nxb7 ( 2.g3 b4∞ ) 2...Kxb7 3.exd5 Nbxd5 4.Nxd5 Nxd5 5.Bd3 f5 6.Rhe1 Qc7 7.Bf1 c4∞

Here is the zip file that holds almost every published analysis of this game, including Kasparov's comments after the game. It was also instructive to go through the comments of top GMs as well as other "lesser players" who used engines for the analysis. Just click on the spinning red box:

SUMMARY:

Although White has better pawn structure, he is behind in development and his queen is misplaced.

Black does have a backward pawn on d6 and has compromised his pawn structure on both wings but that is not so bad for him since his pawns restrict the opposing light pieces. He has more space on the queenside and a chance to obtain initiative on that part of the board, while his holes on dark squares on the kingside can not be effectively exploited. He has wonderful piece coordination and activity and will achieve the freeing d5 break, eliminating the weakest piece in his setup, thus achieving full equality.

I evaluate this position as sharp/unclear with equal chances for both sides.

As for Topalov losing this one, you must be aware that Kasparov tried a3 as a novelty, which probably threw Topalov out of balance a little, so he misplayed it in the end. He was probably in time pressure, or simply lost focus due to calculating all the possibilities in a new position which is always a difficult task. Up until cxd4? he played well, even Kasparov had to award exclamation points for some of his moves.

Hopefully this helps. If you have further questions leave a comment.

Best regards.


Why does White play 13. f3 and not 13. f4 in the Modern Benoni, Classical Line?

I played this position many times with white and f3 is really good move here.

It is not only about what white wants, but also about what black wants. You have more space and so you can choose easier from more plans. You can play for Rb1 b4, you can play for g4, you can play for f4 and e5. Black has not that much space and can't choose from many plans.

Now look at the position. Who will be happy to see f4 and potentially e5? Probably you in the beginning, but then also Qd8, Re8, Nf6 and Nc7. That is quite a body count. They don't have much work now but will have plenty of job after you weaken the centre. What about your pieces? Both knights will lose part of its mobility as they will have to protect pawn on e4. Bishop on c1 will hate you. Maybe you will help Rf1, while Qd1 and Be2 will see also slight improvement of their chances, but simple adding pros and cons of f4 action compared to f3 should lead to clear NO!. You won't loose the e4 pawn just by playing f4 or anything like that, but by this overextending on part of board where you really are not stronger, you achieve nothing positive at all.

The plan is good only when it helps you more than your opponent!

The f3 alternative with killing opponent's bishop immediately on c4 (f3 Ba6 Nc4 Bxc4 Bxc4 is the main line and for good reason, as black can't afford you to play b3 and retake on c4 with pawn!) saves you material advantage of bishop vs. knight, doesn't commit you to anything and then you can calmly go either for Rb1 b4 or some other stuff depending on black answer.


Why is c4 a better move in this position?

White intends to play c5, which will gain space on the queenside and severely cramp black's position (The b6 knight has no good square).

On the other hand, e5 weakens white's control over d5 and f5 (e.g. Black can then go ...Ne7-f5).  Black could also take advantage of the weak c4 and d5 squares with ...Na5 and ...Bc6.  Keeping the pawn on e4 seems better.  It also keeps the h2-b8 diagonal open for white's unopposed dark-squared bishop.  Preventing black from playing f6 does not seem very important to me.

By advancing c3-c4, the c4 square also becomes less of a weakness because it can now be covered from the rear with Qc2 or Rc1, which is impossible with a pawn on c3.

Slightly weakening d4 is not a big deal, because it's easier for white to defend d4 than it is for black to attack it, since white has a big space advantage and a dark squared bishop, while black is quite cramped.


Bxf2+ gives away all your advantage because of the precise line you mention. The correct move is e5 (to protect your bishop with tempo, note 1...e5 2.O-O exf4 3.Qxd4 doesn't work because of Ne2+ fork), followed by Ba6, preventing castling and attacking the trapped a8 bishop. Notice Bc6-Bd7-Bg4 doesn't really save the bishop as shown below: (covering some side-variations as well, rather called for as it's a very concrete position)

 [title "1...e5"]
 [fen "B1b2rk1/p3pp1p/6p1/q1Pp4/3b1B2/2n4P/P2Q1PP1/2R1K2R b KQq - 0 1"]

 1...e5 (1...Qxc5 {also a good move with similar threats except the queen discovery} 2.O-O Ba6 3.Rfe1 Rxa8 4.Be3 Bxe3 5.Rxe3 d4 {easily winning: two pieces and a pawn for the rook, together with a passed pawn and dominant knight}) (1...Ba6 {The immediate Ba6 is not good enough probably but it's a fun line, the idea with Ne2+ forking bishop and knight while still taking on a8.} 2.Qxd4 Ne2+ 3.Qd2 Qxd2+ 4.Kxd2 Rxa8 5.Be3 Nxc1 6.Rxc1 {still a pawn up but it's opposite colored-bishop so always big drawing chances.}) 2.Bh6 Ba6 3.Bc6 (3.Bxd5 Rd8 4.Bf3 Bxf2+ {wins on the spot for black}) (3.Bxf8 Bxf2+ {however white recaptures loses on the spot} 4.Kxf2 Ne4+) Rc8 4.Bd7 Rxc5 5.Bg4 Bxf2+ 6.Qxf2 Ne4+ {and you're winning the house.}