# Question
Title: How do I handle drawn positions in zero time increment games?
I recently found myself in a drawn position (king and rook for each side) in a zero increment online game. I had about 10 seconds on my clock, my opponent had about 20 seconds. He ignored draw offers, and I eventually lost on time (despite trying to premove as much as possible) as we shuffled our pieces back and forth.

How could I have better handled this situation?

# Answer
K+R vs. K+R is a draw, but K+R+10 sec vs. K+R+20 sec is *not* a draw. Your opponent won because they had an advantage brought on by having better time management. Nothing to complain about -- time is an essential resource (sometimes more important than material) in blitz (or similar) chess. The only real answer to your question "How could I have better handled this situation?" is -- try not to forget the clock.
> 45 votes

# Answer
If you are sure not to make it over 50 moves for a draw, another option not yet mentioned is to try to trick your opponent. Likely they will also premove.

For example if in a R+K vs R+K you are both moving the king around at some point prepare to move your rook to attack their rook even in an undefended way. Chances are they will have premoved the king and you can just capture the rook, which at least draws and maybe even wins.

I recommend this only if the opponent refuses a draw otherwise I find it poor style, as is playing 10 seconds vs 20 seconds K+R vs. K+R in a usual blitz-game.

That's actually a drawback of online and also electronic clocks. With analog clocks this happened much less, as there was inherent uncertainty regarding the remaining time.
> 14 votes

# Answer
## **Preface:**

When two players agree to play a timed game, they have agreed to take a loss if their timer ends before they can defeat their opponent. As such, time is a resource that affects *every* such match - time management should not be considered secondary to advantage on the board. Chess skill is not simply about being able to find the right moves, it's about finding the right moves fast. Long classical time formats place an emphasis on extreme precision, depth, and accuracy by affording the players more calculation time to find deeper ideas faster. Shorter rapid time controls promote speed and quicker recognition. In any timed situation, an opponent who thinks the same way you do but faster will be stronger than you are.

Part of the strategy of a no-increment game is playing fast enough to put your opponent in serious time trouble, and since time can never be regained, often this means winning the game by expiring your opponent's clock. While it may be sometimes referred to by the unflattering term "dirty flagging", **it is no less legitimate of a win than a checkmate or a resignation.**

---

> I recently found myself in a drawn position (king and rook for each side) in a zero increment online game. I had about 10 seconds on my clock, my opponent had about 20 seconds. He ignored draw offers, and I eventually lost on time (despite trying to premove as much as possible) as we shuffled our pieces back and forth.
>
> How could I have better handled this situation?

The fact that you are in a drawn position with only ten seconds on your clock is a huge disadvantage. In fact, while the position might be a draw with best play, your opponent has managed to pull you into this endgame while severely exhausting your time - the phrase "drawn endgame" here is a misnomer, as your odds of holding on for a win are very slim! **The ideal way to deal with this situation is to not get into it the first place.**

This might mean practicing playing moves in the opening much faster, or training oneself to spend less time calculating earlier on in the game, or simply not playing games with no increment in the first place. In fact, you may have even made a mistake by going into this positionally drawn endgame while down time - perhaps you could have noticed that you would lose on time in an endgame and tried to keep your pieces on the board? Other options may not have been theoretically sound, but if you're going to be down to only ten seconds on the clock, it may be better to start a quick unsound mating attack than to play out the draw and guarantee yourself a loss!

Inevitably, though, all players will find themselves in the situation described in the question: down on time and scrambling to hold onto a position, especially with no increment. There are some tricks to try and salvage games, though:

* **Look for stalemating options.** If you already have few pieces, you may wish to simply throw away material in order to reduce the number of legal moves you can make and raise your opponent's odds of causing a stalemate. You may even intentionally pin your pieces to your king to try to get a stalemate out of nowhere, or run your king towards dangerous squares on purpose in the hopes that your opponent will accidentally leave you with no moves.
* **Move as fast as possible.** Obviously, every millisecond you spend increases your chance of losing - try to think on your opponent's time where possible. Premoves are your friend, try to string together as many as you can.
* **Take the initiative.** Look for any attacks, checks, and forcing moves. Your opponent will likely have to spend more time than normal when placed into check or when their powerful pieces are attacked - make them react to your moves if you can. This will give you more time to think, and may put your opponent into time trouble as well. By contrast, if you have to react to your opponent's checks, you will quickly lose time.
* **Anticipate your opponent's moves.** If you are defending, look for your opponents checks. A smart opponent may prioritize playing checks and forcing moves quickly to flag you, so be ready to step out of check or block nearly-instantly.
* **Insufficient material.** If you can trade down to a situation where the opponent doesn't have enough material to mate you (King vs. King + Bishop, etc), the game will instantly be drawn! If ahead or in a drawn position, try to trade an opponent down to just a lone king, so that if your clock runs out, it will be a draw rather than a loss! Be aware that pawns for either side can prevent the insufficient material draw from triggering, since with a pawn or two on the board, there may still be legally-possible checkmate positions that could use a pawn to limit its king's movement enough for a checkmate. For example, while checkmate can't be forced in a KNN vs K endgame, a mate could still happen with errors by the defense. Thus, draw by insufficient material will not occur.
* **Forget about accuracy.** If you don't see any better objective to go for, find any legal move and have it ready - force your opponent to spend time and effort refuting your inaccurate play rather than guaranteeing yourself a loss by taking time to play accurately. You might hang several pieces, or allow a forced mate, and your accuracy score for the game is undoubtedly going to suffer. But your odds of winning will still be increased, since your only hope of survival is to keep your clock running for as long as possible. And you just might play some of the best moves by chance, too, so be on the lookout for your opponent's replies to your moves. Give your opponent a chance to make a big mistake!
* **Go for draws by repetition.** Try to repeat moves as often as possible, look for perpetual checks and shuffle around two or three squares and hope for a draw.
* **Offer a draw.** No, you don't deserve one - your opponent would be a fool to take it -, but you may just find someone who will. However, one or two offers is enough. Any more than that, and you're simply wasting your own precious time - if they want one after that, they can send you one themselves if they missed the first few. Plus, spamming draw offers to an opponent who has already rejected your offer could be seen as unsportsmanlike - I imagine the argument would be that it's an intentional distraction when overdone?
* **Be unpredictable.** You may get some leverage out of playing nonsensical or counterintuitive moves, especially if your timer woes are also affecting your opponent. Your opponent might not see that your rook was unguarded and bite on your tricky move. Or your opponent might have premoved something that will stalemate you if you do something unexpected.

Once in this situation, you'll probably lose, so the stakes are already at their lowest. You'll definitely lose if you don't go for something! Try to avoid getting into this position, and spend an appropriate amount of time thinking for the time control being played.
> 7 votes

# Answer
* Exchange off all the pawns, and enough material to ensure that your opponent no longer has enough material to checkmate you (e.g. your opponent just has a king + bishop versus your king).
* Find a repetition of position and repeat it three times, e.g. a perpetual check, or a forcing sequence where your opponent can only break the sequence to their disadvantage.
> 4 votes

# Answer
Top priority is to accept the situation and maintain composure. Begging for draw does not belong to that. If your opponent wants to squeeze out a win on time, let him. It is ugly, but his natural right, to punish you for not having disposed your time correctly. The player making the same decision in less time is simply the better player. It is the way world class chess is played. There is no other way. Imagine you were *not* allowed to win on time. Nasty opponents would soon learn how to take advantage of that and the situation would be far worse than before.

Edit: Don't ask me, learn from the best. According to Live Chess Rating Nakamura, Carlsen and So are currently (July 2021) the best blitz players. Watch them playing on youtoube and see how they handle time, time trouble and loss on time.
> 1 votes

# Answer
The only option you had was to capture his rook, making the draw obvious. That is if you had kept him in check. But it is very unlikely that you had a position where he could not do anything else except protect the king with his rook since the only such position would be a checkmate (providing he has no rook,) and then he places his rook between your rook and the king.

Anything else is: his win.

Another option was to see his time advantage upfront and play for the obvious draw, not rook-rook. This is because for quite some moves the position was a draw. Just make it more obvious next time around. Unless you have time advantage of course.
> 0 votes

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Tags: endgame, time-control, time-management
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# Question
Title: Why do you see peaks on the elo distribution?
I was observing the elo distribution in Lichess and noticed peaks around rounded numbers elos ratings for medium to high rated players. This is consistent in Bullet, Blitz, Rapid games and not so much in Classical. I would have expected to observe a smooth curve.

Does anyone have an explication for this phenomenom?

My own explanation is that people tend to play until they get a nice number and stop for a while. I know I do this sometimes. In Classical playing to many games is not an option because obvious reasons and so the curve is smoother.

# Answer
This is because Lichess is plotting the curve, taking 25 rating points as a unit. That's why you can see coordinates on X-axis 25 points apart.

Now, let's understand the concept with an example. Say, Lichess is using Floor(25) to plot the graph. So, If your rating is 1979, it will consider your rating to the multiple of 25 you have just passed (i.e., 1975). Let's say, you have lost a game and your rating has gone down to 1972, then it will consider you in the 1950 tier.

Now the obvious question is **Why?**

As you can see, this is a frequency plot (Non-cumulative). Now, assume that you take the unit of your plot as 1 (instead of 25). Also assume, the number of the players as follow:

| Rating | No. of Players |
| --- | --- |
| 1900 | 37 |
| 1901 | 23 |
| 1902 | 3 |
| 1903 | 7 |
| 1904 | 17 |
| 1905 | 32 |
| 1906 | 33 |

Now, if you plot the above imaginary data, it will be **very hard to understand the trend of the rating** due to numerous peaks and crests. That's why, a good practice will be to form a normalized group or say a rating range first (Like in this case, 1900-1925) and then plot the graph taking the range as a unit. In this way, you can visualize the data better.

Now, you as well as another person in the comments have already pointed out that people always try to achieve a milestone (i.e., 1500,1600,1700,...) and halts playing for a couple of days to keep their rating in that milestone. That's why You can see the micro peaks tend to happen in the first quarter (i.e., 1500-1525, 1600-1625, 1700-1725, and so on). This milestone mentality is common in amateur players (1600-2100). Absolute novice (\<1200) or absolute strong (\>2300) players play regularly. That's why micro-peak is not common in those regions.

Last but not least, you may ask whether we can make the graph smoother (Something like in chess.com).

The answer is **YES**. You have to use **moving-average** for that. But, that doesn't reflect the trend of the mid-tier milestone-mentality. I think that's why lichess sticks to this plot for better insights into the rating distribution.
> 4 votes

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Tags: statistics, elo, lichess
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title: Does white have an advantage?

text:
# Question
Title: Does white have an advantage?
It is often debated that white has an advantage over black. Some even say that with perfect play on both sides, black simply cannot win. Is there any research that backs up this claim, or is it mere speculation by the greats such as Rauzer?

Also, if this has been or could be proven true, could the black pieces be given some sort of aid to make them equal to the white ones?

# Answer
> 40 votes
These statistics come from a database of over 600,000 games:

```
White wins   37.35%
Black wins   27.41%
Drawn        35.23%

```

http://www.chessgames.com/chessstats.html

The stats suggest that White has a significant, measurable first-mover advantage. Not an overwhelming advantage, but better than the house advantage in any casino game.

Is that advantage structured into the game or psychological? Comparative stats on games between mature chess engines may help to decide that.

# Answer
> 14 votes
The most comparable game to chess that has been solved is checkers, where it has been shown to be a draw given perfect play by the second player. The first move gives a player a very slight edge initially, but does that convert to a winning advantage?

Tablebases give us some insight into the debate. The vast majority of positions which are materially balanced result in draws. Positions that are somewhat dynamically balanced (say knight vs bishop) still result in draws a high percentage of the time, although the more powerful the remaining pieces are, the more likely first to move is the winner. (take for instance, KQRKQR endgames, the first to move wins 67% of the time).

Another important factor seen in tablebases is that most wins have a relatively short distance to conversion (or moves to force a win). There are extreme cases, for instance, the record had jumped from 292 moves in 1989 to 330, 545 in 2006, and then to 549 in 2014. The striking quality to me is that the gap between move lengths in these records jumps so much all at once, which suggests that it gets harder to force a win the more moves away from the end you are, because most positions that far away are draws. It would be a winning lotto ticket if starting from the opening position, it happened to be one of those extremely long won positions. To me, this is strong circumstantial evidence that chess will be another game shown to be a draw.

Unfortunately, it is currently impossible to generate a full 32 piece tablebase for chess, as there are more possible chess positions than atoms in the universe. Barring some breakthrough in quantum computing allowing all possible positions to be evaluated simultaneously, I doubt chess will ever be fully solved by man.

# Answer
> 11 votes
One solution for equalizing a first-move advantage is the **Pie Rule**, AKA "I cut, you choose".

Under this rule, immediately after the *n*th move by White, the player that started as Black would have the option of either switching sides or proceeding with game as is. The number *n* is fixed in advance.

This rule is used in other boardgames, like Twixt, Havannah, or Hex, that have a more significant first-move advantage. With the Pie Rule, the first player must quickly give up the advantage lest it be seized by the second player.

The more common solution, since draws are acceptable in Chess, is to play multiple games, with players alternating sides.

# Answer
> 5 votes
The first move in chess affords a slight advantage. This is why pairing systems try to alternate a player between the white and black pieces. Some GMs are 'underrated' because over time, they have randomly been assigned the black pieces more often than is normal. They are at a slight disadvantage and thus lose an unnatural frequency.

I have never seen it demonstrated that with perfect play white (or black) will win.

# Answer
> 5 votes
This is an open problem, but historically:

> Since 1851, compiled statistics support this view; White consistently wins slightly more often than Black, usually scoring between 52 and 56 percent. White's winning percentage is about the same for tournament games between humans and games between computers;

In the recent games played by AlphaZero against Stockfish:

> With White AlphaZero \[vs. Stockfish\] scored a phenomenal 25 wins and 25 draws, while with Black it “merely” scored 3 wins and 47 draws. It turns out the starting move is really important after all!

So, if the performance of AlphaZero is evidence of what the best current possible play is, white does indeed have an advantage.

It would be interesting to see the statistics on white/black wins of AlphaZero playing against itself.

---

Source:

# Answer
> 4 votes
I think statistically it has been shown that White has the advantage, but as the saying goes, "The winner of chess is the player who makes the second to last mistake". White only has the advantage on the first move and this would not matter if they make a horrible second move. I would also say that White has more of an advantage at top level play because there are not likely to be too any mistakes, but at the lower level, being White or Black does not offer much of an advantage because there are probably many mistakes.

# Answer
> 3 votes
I have analyzed the statistics of the top players in history, and the top chess engines of the last few years, and found that white has a distinct winning and scoring advantage except for one player (Lasker, who was about 1% better with black!). The stats are:

Top players of history: white wins 7.5% more than black, white scores (wins plus draws x .5) 2.5 % more than black Top chess engines to date: white wins 37% more than black white score 34% more points than black

For comparison, the stats for: All players (several million games in public databases): white wins 13% more, and scores 8.5% more Hundreds of 1000's of games from available chess engine games for last 8 years (over 1500 engines): white wins 15% more than black, and scores 14% more than black.

The higher caliber of human player, or higher rating of the chess engine, the higher the advantage for white (ranged from 1 to about 40%). For me, this is pretty good evidence that white has a big advantage, since both the top players and basically ALL the engines achieve more wins and points as white. The best engines rarely, if ever, lose as white, but lose more often as black. Yes, engines draw more than top humans (about 50% compared to 20-30% for humans) but the remaining games are won most often by white. The top human players ranged from 1-22% more wins with white, while the top computers ranged from 6.5-44% more wins by white.

Of course, since chess isn't 'solved' then we can't be sure, but the top players, who look ahead 20-30 play, and the top computers, who look ahead 30-50 ply easily now, are a good indication that white has a definite advantage. Perfect play by both sides is still a mystery, though! :) John

# Answer
> 2 votes
Looking at the statistics shown by Sunanda above, it appears that white has some advantage. I feel it is more a question of human brain's (or machine's) capability to handle 8x8 squares to maintain that advantage for white or achieve equality or advantage) for black. With this in mind I tend to believe that white's advantage is more if the size of the board is say 5x5 or 6x6 (of course with some pieces removed from the board). The simple reason for my belief is that the game becomes a lot easier with smaller sized board. On the other side, if the board is large say 12x12, with some additional pieces and pawns, the game would be lot more difficult for white to have any advantage, because there would be many more possibilities for the moves at every stage of the game. First move advantage may actually cease to exist at some size of the chess board (as we move from small to large size for the board). This size at which it breaks has to be found out. To digress a little, some game designers have come up with chess variants to eliminate this supposed advantage. Google for Synchronous chess, parity chess and synchronistic chess to know the rules of these variants.

# Answer
> 2 votes
There is not a single game where white wins **because of** the first move advantage. All wins for white are related to something else (e.g. blunders or more inaccuracies). If both sides play perfectly (i.e. achieving the most out of a move according to any decent algorithm), the game ends in a draw.

But it is difficult to play 50+ moves perfectly. Either side will go wrong sooner or later. Apparently this happens to black more. Maybe it is just psychological: chess players are told that White has the initiative from the start and that Black needs to respond to that initiative and try to equalize. Responding to the other players plan is more difficult. Based on a single move played and the current position, you need to understand what the opponent is trying to do. As long as mind reading is not allowed in OTB games, mistakes will happen.

The interpretation of the stats, are misleading at best. It assumes that difference in winning percentage can only be explained by the first move advantage, and that is demonstrably not true.

# Answer
> 1 votes
Some here have stated that white has a one-move advantage, which is certainly incorrect.

White has a half-move advantage. It is true that before each black move, white is ahead one move. However, after each black move, equal moves have been made by each side. Averaging all decision points in the game yields a .5 move advantage.

Also, it is easy to see that there are a number of ways to give up a move immediately in most real-world games, if having it were not actually an advantage.

If we take a simple example of a mirrored game, where black attempts to duplicate every move of white's, white will rapidly be ahead material. You could argue that being ahead material is not an advantage in some configurations, but having the choice to take that material, having more control of the outcome, certainly is.

You might find the previous concept absurd, but let's look at it from another perspective. Given every possible exactly mirrored board position, it seems intuitive that more of them would be mate-in-one for the first to move. (I have not done this calculation, but it would be an interesting and probably achievable search to run.) If we broaden this to all possible configurations, it seems intuitive that mate-in-one would on-average be more accessible to the first to move. Etc. And we need not follow this trail too deeply, either. Forced mate-in-six is a challenging find for most humans.

Many people have played many games of chess, some without any preconceived notions. If a clear way to neutralize white's opening advantage with certainty had been played, it would be well-documented by now. In fact, much opening strategy exists in chess surrounding this concept. See chess "tempo".

In endgames a well-known concept is zugzwang, where a clear disadvantage exists to having to move. However, this disadvantage exists because of the lack of choice, not because of having first choice; the move a player must make is disastrous (or more accurately the disaster has already occurred). Reiterating tbischel's comment, chess may never be solved by man. Because of this, we play games forwards, rather than backwards, as humans - and because of THAT, having the first move is an advantage.

# Answer
> 0 votes
Your question turns on the meaning of perfect play. If White starts with a Colle system and neither player offers any aggression I cannot imagine that the result is anthing but a draw. For one side to win, at some stage an ambitious move must be played to unbalance the position.. If it turns out that this move actually gave the advantage to the opponent then it could not have been perfect play. In the days of Alekhine and Capablance, many players expressed fear that Chess would experience a draw-death, Instead, the Kings Indian became popular

# Answer
> 0 votes
In Chess White has an advantage or not depends upon who is playing and what opening is played on board . Man or Machine.There are statistics to prove and both disapprove . Playing white for Humans is more of a Psychological thing and for Machines it hardly matters .

Generally from the opening itself if you take any powerful Chess Engine Fritz/ StockFish/Komodo they will show a Score slight advantage of +0.3 to +0.7 even if the most accurate Openings are played .

If it is Sicilian then the Score will incline more and if it is Petroff then the Score will be less . Please remember Petroff is the only defence where White has not been able to find a real advantage . So it really depends upon the Opening and the Player who plays White .

I will take the best instance of WCC matches from Lasker, Alekhine, Capablanca to Carlsen where both Players have got equal number of matches with both white & black and the mightiest Player have always won with their respective chosen openings.

# Answer
> 0 votes
Wondering if this may have something to do with white possibly having a greater ability to push the game down a line of play for which white has spent more time preparing. This may mean that Black is more likely to run into time constraints as they are have to spend more time figuring out the right response. Play at a high level seems to some extent to be to follow common lines of play for first set of moves and to then to try to push game into a less common line of play where you may have spent more time preparing/which you are more used to playing/where you have an advantage. To extent to which this is easier for white, there may be some advantage.

# Answer
> 0 votes
The situation is more complex than what statistics is telling you. A chess has a fractal structure, that is given, and this is actually explaining the high number of positions. Some endings are quite obviously fractal, because the outcome depends on, even though the arrangement is the same, whether the position is to the left or to the right of the center and so on.

First statistics

White wins 37.35%

Black wins 27.41%

Drawn 35.23%

This is actually answering the question if black wins more often than white. But that is not the question. Draw is a position when neither white nor black can win, but this is really far from white and black being equal. Only if we would analyze draw positions and measure the positions value, we could really add something to this analysis. What I'm saying is that this analysis has to be refined. At least it would have to be done separately over all possible combinations over the first move (2 plies), since black and white have a predefined set of choices. They simply have to move some of these.

Once this is done, you would eliminate those that are giving a strict advantage to the white or black.

Additional analysis would have to say the percentage of games where one player played a blunder. This would eliminate most of the psychological elements of the statistics.

Now you are left with how humans, and this is very important to understand, humans play chess. With the advent of computer chess, you can find that almost all chess players call the moves a computer makes: a surgical and sterile, something that is mathematical correct, but generally devoid of any strict plan or idea.

And here comes the problem:

1. Can you describe every move in chess by human logic in form of attack, tactics, defense, trap...? The answer is a resounding no, and this is why a computer can play "better", because it is not human. It knows about the logic of how human plays since its algorithm contains it, but it does not understand the game the way a human does. It constantly measures.
2. Since how humans play is not mathematically the most precise way of playing, here comes the question of our knowledge about chess, i.e. what part of chess can we describe and learn?

So if you take that the answer to 2 is very much but not sufficient, since it seems that computer will be able to reach 3500 or maybe even 4000 ELO quite soon, while humans will not go much beyond 3000 ELO any time soon, we probably can play, at best, at about 80% of how chess *can be played in order to decide if chess is draw*.

All together:

Regarding the way humans play chess, it seems that white might have a decisive advantage because the theory around how black should play in order to win is not developed enough. Since chess is a fractal game, any mistake black makes is then easily more detrimental to the final result than a similar error white would make.

Basically a small disadvantage a black has, because of the initial position AND knowledge we have, is putting him instantly at the edge of the known *human* logic of playing chess. A player must be more cautious and more inventive and any small mistake white would make requires more effort to turn into a full advantage.

Theory of chess grows, but the total effort of a relatively limited number of players will always be limited by human intelligence. At the moment, if you look at the statistics, you can see that the best lose a little bit more between black and white, Carlsen 10%, the rest about 60-80%. But none of them know *how to win with black*. In that sense, it is obvious that our current knowledge gives the white a sufficient advantage to get a draw easier. And this is placing black in a disadvantageous position not to make a mistake. And then word "human" comes into play.

Once computer reaches 4000 ELO we will know much better if chess is really a fair game. Until then white has a sufficient advantage to place black into a submissive position. It would be great to calculate this in form of ELO points, of course. I cannot know but I think it is less than 100. Regardless of this random guess, it is a definite conclusion that we have to speak about how we play chess and how chess can be played as two very different topics.

# Answer
> -1 votes
Though taking it from a suggested article, there is a great need to point it out literally as it is the best argument.

"*The first-move advantage is founded more in psychology than in reality.*" - Andras Adorjan

**Explanation of above conjecture:**

First-move advantage doesn't just exist in Chess but approximately in all games **but theoritically** (pychologically). This is often neat. Come, play football! Let team A (say) start the game then, if, both teams A and B play perfect games (equal play), A is going to have first Goal. But this is certainly all theoretic. This has very small to do with Reality (as it happens nearly never) since, one team is always going to play different from other. This either results in a Draw (before penalty shootout) or a win/lose.

> The point is, "theoretically, things seem much different as they look practically". This is why the problem is a chess theorists' problem and not of chess players!

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Tags: theory
---


# Question
Title: What is the etiquette (or tournament rule) for the act of capturing a piece?
There are a few different possible ways of capturing an opponent's piece. You could:

* Pick up both your piece and their piece simultaneously with both hands, then set your piece down where their piece was.
* Pick up both your piece and their piece using the *same* hand, and then set yours down.
* Remove their piece from the board first, and then use the same hand to move your piece.
* Pick up your piece, use it to shove theirs out of the way, set down your piece, and then remove their piece.

And perhaps there are a few other ways as well.

Which of these ways are the best etiquette? (The "shove theirs out of the way" method seems particularly inappropriate.) Are any of these ways illegal under tournament rules? (Don't the USCF rules say that a move must be made with one hand?)

# Answer
> 28 votes
Seeing how Super Grandmasters capture pieces can be instructive:

### Garry Kasparov

Capturing an adjacent piece:

Capturing a distant piece:

Source: YouTube

### Carlsen (white) vs Caruana

Source: YouTube

### Aronian (white) vs Morozevich

Source: YouTube

### Hikaru Nakamura (white) vs Vladimir Kramnik

Source: YouTube

### Summary:

With the exception of Kramnik, captures proceed as follows:

1. Lift the opponent's piece and palm it.
2. With the same hand, move your piece.
3. Stop the clock using the hand holding the captured piece.
4. Table the piece.

It's worth noting that it's OK to table the piece in your opponent's time; you do not have to table it before you stop the clock.

Kramnik (playing black in the final image) lifts his own piece before transposing it with Nakamura's pawn in one quick snap. Kasparov also does this with the pawn capture in the first gif. This isn't wrong, it's just a different – and perhaps more aggressive – style. It does not matter if you lift your piece or your opponent's piece first, but all high-level players touch both pieces and the clock with the same hand. (Note that Magnus as white tables the piece on his right even though the clock is on his left.)

It's probably safer not to use two hands for captures or castling, as tournament rules vary on the use of two hands, and it's been a source of controversy in the past. e.g. Giri vs Epishin, Supercube Blitz Utrect, 2009 (scroll down to "The Incident").

# Answer
> 8 votes
Remarkably, I wrote a blog on this topic last night. It is available here - http://www.chess.com/blog/SamCopeland/how-to-move-a-chess-piece.

To quote myself...

> Both Magnus and Hikaru execute their captures by first picking up their opponent's piece, then they slide that piece to the back of their hand to be held by the ring and pinky fingers within their palm. While holding the captured piece, they move their own piece to the capturing square using their thumb, index, and middle finger. Some other players make each move independent. They first remove the captured piece from the board, only then do they move their piece to the capturing square. This can be a noble styling, but it costs precious time in blitz and lightning games.

Regarding legality... Yes, a move must be made with one hand. This is to prevent a player moving a piece and pressing the clock before completing the move. Otherwise, all of the methods you describe are legal, but you are right that using the capturing piece to knock their piece over is rude, and likely to knock pieces over.

# Answer
> 6 votes
I have seen the following. I use technique #1 though as long as one doesn't smash the pieces they are virtually the same.

1. Pick up both your piece and their piece using the same hand, and then set yours down. (pick up my piece first, placing it on its new square, and scooping up the opponent's piece in one motion.)
2. Pick up your piece, use it to shove theirs out of the way, set down your piece, and then move their piece.

Use one hand, and don't take your hand from the board until the entire move is complete. If you touch one of your pieces, you have to move it. If you touch one of you opponent's pieces, you have to take it.

# Answer
> 1 votes
Updated answer on 5 March 2016:

1. Take the opponent's piece into your hand.
2. Place your capturing piece on this square with same hand.
3. Press clock with same hand.
4. Place captured piece next to board.
5. Write down your move on your score sheet.

# Answer
> 1 votes
# Tournament rules

You say that under USCF rules, each move must be played with one hand only. I do not know if that is true. But under the FIDE Laws of Chess, article 4.1, it is true:

> Each move must be played with one hand only.

We can go further than that: you must use that hand to press that clock too (article 6.2.3):

> A player must press his clock with the same hand with which he made his move.

# Etiquette

The only important points about etiquette are:

1. Follow the rules.
2. Do not press the clock using the captured piece (but pressing the clock with the captured piece still in your hand is fine).

Everything else should come automatically, as long as you aim to play *efficiently*. In moves that involve multiple pieces, handling only one piece at a time (except in castling, where you have to do this) is inefficient. Making a mess is inefficient. Players who make a mess risk moving pieces off the correct squares, which they must fix on their own time (article 7.4.1):

> If a player displaces one or more pieces, he shall re-establish the correct position in his own time.

Other answers look to advanced players for examples of how to handle pieces. Naturally, those players are efficient, so they are good examples.

# Answer
> -3 votes
You must never touch/capture an opponents piece first because this would allow you to sit there contemplating, for as long as you want, which of your pieces to use in the capture, thus obviating the concept of chess being a game which requires you to visualize positions and actions before you make them. The correct process is to pick up your piece and while holding your piece and using that same hand remove the capured piece and put your piece on the vacated square. I have been abused of this rule, but I invite a rational explanation why you should be permitted to touch your opponents piece first.

---
Tags: rules, tournament, etiquette, best-practice, captures
---


# Question
Title: Why do receive higher ranked players a downfloat in fide swiss pairing?
I am trying to grok the fide specification of the swiss pairing algorithm, having a hard time with that. For example rule A.4.b reads:

```
A4
[...]
b
After two players with different scores have played each other in a round, the higher ranked
player receives a downfloat, the lower one an upfloat.
[...]

```

According to definition A.2 the player rank changes dynamically, round after round. My main question here is, at what time the rank of the two players is considered, before or after the round? I personally see arguments for both interpretations.

If I understand correctly, swiss system tries very hard, not to pair moved down players against each other, this is only considered if all other possibilities are exhausted. Hence if a player was moved down because of rule A.4.b or for some other reason he will be likely paired against a player with different score which is lower ranked before the game and subsequently be eligible for another application of rule A.4.b, either unconditionally or if he stays on top of this opponent. Hence because of rule A.4.b I expect downfloats to be positively correlated, which seems to contradict the main pairing construction.

It would be helpful if someone with experience in this matters, could either confirm or correct this interpretation and provide some intuition, for what rule A.4.b was introduced for.

# Answer
> 0 votes
> After two players with different scores have played each other in a round, the higher ranked player receives a downfloat, the lower one an upfloat.

This is just marking the fact that the higher ranked player had to downfloat and the lower ranked player had to upfloat. The algorithm tries to minimize the number of times this happens to the same player, at least for the next couple of rounds.

It uses the ranking from the start of the round, not the one after the game is completed. It would make little sense to consider an upfloated player to have downfloated just because they won the game. I imagine that it's applied after the game just to take into account the possibility of a forfeit; you wouldn't get an upfloat or downfloat marked to you just because you were *paired* that way if you never actually played the game.

# Answer
> 1 votes
> According to definition A.2 the player rank changes dynamically, round after round

No, I don't think you fully understand what is going on. During the pairing process for a particular round in a given score group the ranking within a score group is fixed according to what the original ranking before the first round.

> A.2 Order
>
> For pairings purposes only, the players are ranked in order of, respectively
>
> a score
>
> b pairing numbers assigned to the players accordingly to the initial ranking list and subsequent modifications depending on possible late entries or rating adjustments

If there are no new players to add and no initial entry errors to correct then the initial rankings apply for the complete tournament.

There are only two situations which can give rise to changes to these rankings. These are:

1. a new player joins the tournament after the initial ranking. In this case the ranking list is changed by inserting the new player in their slot according to their rating.
2. an error is discovered in the rating entered for a player in the initial ranking. In this case the rating is corrected and if this changes the place of the player in the ranking then this change in position is confirmed.

An example might make it clearer. Suppose in the first round of an 8 player Swiss, with players called in ranking order, "1", "2", "3", "4", "5", "6", "7", "8", with player 1 having white and where all the white players win. Then for the second round there will be 2 score groups with the 2 groups having the following internal rankings.

**Score Group 1 point**
1
3
5
7

**Score Group 0 points**
2
4
6
8

Suppose then that a new player, player 9, joins with a rating between player 2 and 3. Then the new overall ranking would be: 1, 2, 9, 3, 4, 5, 6, 7, 8 and this ranking would remain for the rest of the tournament. However for round 2 this would change the second score group as follows:

**Score Group 0 points**
2
9
4
6
8

---
Tags: rules, fide, swiss-pairing
---


# Question
Title: Notation for ambiguous moves with three pieces or more
Given three knights that can move to d2, one on b1, one on b3 and one on f3, how would you notate knight on b3 moves to d2? N3d2 is ambiguous, so would it be correct to write Nb3d2? Presume that a player has underpromoted to a third knight in this example.

# Answer
Yes. You should disambiguate by adding either

1. the file of departure (if they differ); or
2. the rank of departure (if the files are the same but the ranks differ); or
3. both the file and rank of departure (if neither alone is sufficient to identify the piece – which occurs only in rare cases where a player has three or more identical pieces able to reach the same square, as a result of one or more pawns having promoted).

Source: wikipedia.

This is an example of 3: neither rank or file alone is sufficient to identify the piece.
> 5 votes

---
Tags: fide, notation
---


# Question
Title: What is meant by "Licensed" in FIDE website?
I was browsing the candidates' profiles of the FIDE World cup on the official website and noticed something interesting.

On the profile page of GM Vladislav Kovalev, a Belarusian chess GM, has an interesting declaration, called "Licensed", which I didn't find on the profile of any other players.

Initially, I thought that this is because he is playing under FIDE and not Belarus. So I checked the profile of GM Alireza Firouzja and there was NO such declaration whatsoever. But, I have noticed another disparity in Alireza's profile. He is enlisted under the Federation of France but his national ranking is calculated under FIDE.

Can anyone please help me to understand about what's going on?

# Answer
> 7 votes
> Can anyone please help me to understand about what's going on?

Yes, it is nice that we can look up our entries on the FIDE rating website but actually there is a business need for this information for arbiters and tournament organizers to avoid fines from FIDE.

Whenever a FIDE rated tournament is rated by FIDE (standard time control only because rapid and blitz, for the moment are free) FIDE charges the federation 1 euro per player for Swiss tournaments and lower rated (average rating \< 2230) round robins. The full details are given in Appendix 2 of the FIDE 02. Financial Regulations / Financial Rules (effective from 1 Jan 2021) document.

Each of the players must normally be registered with one of the federations and those federations also pay FIDE an annual membership fee which is detailed in Appendix 1 of the above document. All national, over-the-board players are normally registered with a federation and so are regarded as licensed. In exceptional circumstances, e.g. a player seeks asylum, a player may for a time be without a national federation and be registered with FIDE as their federation until they settle on a new federation.

Additionally FIDE has its Online Arena where players can register directly with FIDE and play online. Online players who aren't already registered OTB with a federation get a FIDE online registration. This licenses them to play in FIDE's Online Arena but does not license them to play rated FIDE OTB tournaments.

Normally players pay a registration fee to their national federation which covers them for playing FIDE rated tournaments. If players could register directly with FIDE for free and still play OTB FIDE rated tournaments then this would deprive the federations of the money they need to operate.

Therefore if your federation is FIDE (for whatever reason) then you need to pay FIDE a registration fee (which ideally is more than you would pay a normal federation) before you can be licensed to play OTB.

These rules regarding licensing are defined in the FIDE document Regulations on Registration & Licensing of Players / Regulations for Registration & Licensing of Players (effective from July 1, 2015).

Here are some useful extracts:

> 2.5 Players with no Federation are automatically considered to be ‘FIDE flag players’ and their website profile cards indicate FID as their Federation.
> 2.6 *Players registered as FID are provisionally licensed to play over the board rated tournaments after **paying the ‘FIDE license fee’ of 60 euros***. ‘FIDE flag players’ are encouraged to join a National Federation rather continuing to play as FID.
> 2.7 The provisional license under FIDE flag expires on 30 June of the following year.
> 2.8 Before 1 July, the license must be renewed with a payment of 60 euros to FIDE, without further notification from FIDE, failing which the license is annulled.
> 2.9 ‘FIDE flag players’ with a valid provisional license are referred to as ‘licensed’ on their FIDE website profile cards

If an arbiter or organizer submits a tournament for FIDE rating which includes one or more unlicensed FID players then the federation has to pay the license fees, basically a fine. Hence this information (licensed or not) is vital for arbiters and organizers.

Here is the FIDE profile for one of these unlicensed players, Abbagouni, Raja. You will see that in the top right hand corner it says:

> Not Licensed Player.
> **Extra fees for tournament Organizers are applicable**.
> Please refer to FIDE Handbook or proceed to get license

---
Tags: fide, grandmaster, world-championship
---


# Question
Title: In "The Queen's gambit" were there any famous games played?
Throughout "The Queen's Gambit" (Netflix) we see games at an advanced stage (after the opening).

And while the characters are fictitious, the show being set in the 1960s (Beth adult), Benny Watts (US champion) is probably Bobby Fischer, and Vasily Borgov (World champion) Tigran Petrosian.

Were there any famous games (or part of) played within the show? (involving Fischer, Petrosian or any other famous player)

Note: Garry Kasparov and Bruce Pandolfini were the main chess advisors.

# Answer
> 6 votes
Olimpiu G. Urcan has posted several twits about references of historical games and positions that appear in "The Queen's gambit": https://twitter.com/olimpiuurcan

For example:

https://twitter.com/olimpiuurcan/status/1321098273717825536

> Connoisseurs will quickly recognize a small tribute to Bobby Fischer in this very brief #TheQueensGambit scene: it's the conclusion of his crushing win over Bent Larsen from the 1958 Portorož Interzonal. Harmon's 29.d7 (instead of Fischer's 29.Bxf6) still wins, of course.

https://twitter.com/olimpiuurcan/status/1319653477778296832

> Beth Harmon's final game with Vasily Borgov, her Russian nemesis, is based on that spectacular draw between Ivanchuk and Wolff from the 1993 Biel Interzonal.

# Answer
> 6 votes
Agadmator made a video about the final game between Harmon and Borgov which I recommend you to watch. The first 37 moves of that game were identical to a game played between Ivanchuk and Wolff in 1993 Biel Interzonal.

# Answer
> 2 votes
A blitz game in the show, between Elisabeth Harmon and Benny Watts is copied from a famous Kasparov - Van Wely encounter in Wijk an Zee 2000.

Or rather, as Loek Van Wely explained himself on Facebook, did he got tricked when Kasparov used Harmon's game from 1968 in a devilish opening preparation ?

---
Tags: history, fischer, famous-games, film
---


# Question
Title: Why is Bc4 "bad" in a regular Sicilian, yet played almost exclusively in the Smith-Morra?
I know that Bc4 is supposed to be a "bad" move early in the Sicilian, because Black can nullify it by just playing e6:

```
[FEN ""]
1.e4 c5 2.Nf3 d6 (2...Nc6 3.Bc4? e6) 3.Bc4? e6

```

Why is it considered a mistake in these positions, but it's nearly always played in the Smith-Morra Gambit?

# Answer
Bc4 is a reasonable move in most Sicilians. The drawback is that the Bishop might find itself blocked out of the action after ..e6, and the likelihood of that is different in different variations. For example, in the Dragon, Black always plays ..g6 and playing ..e6 as well would leave weaknesses on the Black squares. In lines where ..e6 is played, White usually tries either to sac on e6 or to advance f5. Both of these plans are risky, so White has to be "in the mood". In the Morra, White has already given a Pawn, and these plans are consistent followups.
> 5 votes

# Answer
Bc4 is a good move in every Sicilian. As with all aggressive moves, it provides a target, specifically for a rook on c8, a queenside expansion by b5, and the center pawn fork. The gambit requires active pieces and quick development for the pawn, so not only is Bc4 a good move, but it's necessary.
> 3 votes

---
Tags: sicilian-defense
---


# Question
Title: Is the Two Knights French the only variation where Black is unable to trade off the bad bishop?
I enjoy playing closed positions like the ones from the French Defense, but I despise having to play with the "bad bishop" on c8. I've been trying to research lines in the French where Black manages to quickly trade it off for White's bishop out of the opening, or at least manages to develop it to a reasonable square.

Against the Exchange Variation, there is this:

```
[FEN ""]
1. e4 e6 2. d4 d5 3. exd5 exd5 4. Bd3 Bd6 5. Nf3 Ne7 (5... Bg4) 6. O-O O-O 7. Re1 Bf5

```

Against the Classical Variation, there is this:

```
[FEN ""]
1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 Qd7 (4... b6) 5. a3 Bxc3+ 6. bxc3 b6 7. Qg4 f5 8. Qg3 Ba6

```

Against the Tarrasch Variation, there is this (not gonna cite a specific line, but obviously at some point the bishop can be developed to e6/f5/g4 or traded off for White's bishop on d7):

```
[FEN ""]
1. e4 e6 2. d4 d5 3. Nd2 c5 4. exd5 exd5

```

However, I can't find a satisfactory line for the Two Knights French after:

```
[FEN ""]
1. e4 e6 2. Nc3 d5 3. Nf3 Nf6 4. e5 Nfd7 5. d4

```

# Answer
Not everyone regards "Bad" Bishops as unmitigated evil. Read "The Secret Life of Bad Bishops" by Eben Lund to discover the subtlety of the issues. If you will play the French you must do this. Hopefully you will understand them better than your opponent.
> 5 votes

---
Tags: french-defense
---


# Question
Title: Which methods can be used to prove that a position is illegal?
Given a board position, there are programs that try to find a series of legal moves that lead to it.

Are there algorithms that can do the opposite - prove that the position *is not* reachable by a series of legal moves?

Proof by exhaustion doesn't seem possible in the general case due to the size of the search space, but are there other methods?

# Answer
> 12 votes
Easy illegality is easy: not exactly 1 king on both sides, both kings in check, pawns on the final ranks. It's also fairly easy to tally promoted material and subtract the missing pawns. A quick captures test, together with the pawn structures, is also possible.

An impossibility of last move test, even if only cursorily, is already tricky.

A full test is NP-hard (in whatever sense), I fear. There are many chess problems asking "Legal?" and they can be fiendlishly hard. (Note that the mentioned programs have no chance against them.) In any case, a quick illegality test is far easier than a quick legality test, if the position looks even remotely doubtful.

# Answer
> 4 votes
The only way to decide, apart from obvious cases, is to use backtracking. In doing so, you are basically exhaustively checking each possible move and making a series of moves that would lead to that position. This is no less complex than going forward. Actually, including en passant, promotion, castling, not castling, and capturing a possible piece at any given position it is even more complicated. (Not much of an algorithm, it is just brute force which is the name of the actual algorithm.)

The reason it is more complicated than analyzing possible positions is that some of the positions done in reverse may actually be impossible themselves. But then, it is sufficient to find only one possible chain of moves to claim that a position is possible. The rest of the analysis is more or less wasted.

At the moment we have the 7-piece end game library and we are trying to create the 8-piece library and that will be very likely it. As you can see, even if we reach a 10-piece end game library that is not enough to cover all regular situations let alone irregular ones.

Note that it is a very big problem that you ask only about possible positions, disregarding the fact that people might never play and reach those positions. That is simply throwing away all heuristics that we have, which are designed for regular play style, where you want to win.

I would argue that in general way too many reachable positions are possible, but all totally unrealistic. So instead of going backward for each such position I would probably still go forward simply ignoring all the rules about winning or losing and just trying to arrange figures to get to that position.

This analysis might actually reveal that only some set of positions are impossible, regarding for example pawn structure, but the remaining figures as long as there are no two white bishops etc. are much more flexible. This is basically so, because by disregarding pawn structure you could revert each figure to its initial position first and then if this is so for all positions, only then think about if it is possible that all other missing figures are taken by your opponent.

If I am right, it would leave only pawn structure as the one that defines if a position is possible (even if stupid) or not.

That would leave then to analyze still quite some number of pawn arrangements. But I would definitely start from there.

Anyway I would definitely try to, regardless of artificiality, return each figure to its original position first. This is because it is very easy to offer a figure to the opponent and not ruin the initial structure, you just move the figure until it gets close to whatever it can take and there you are.

This generic approach might actually work in quite some number of cases. But... it is still heuristic and it would require quite some effort to prove that it might be working in general.

Not to leave the story empty handed

The total number of ways figures can be arranged around a table

13^64

since we have 6 different black and 6 different white pieces and one is for an empty space (as you can see I deliberately do not call this *a position* rather just *an arrangement*)

About the number of sensible positions and the number of sensible games, they differ only by a small factor because the branching factor is small. (Suppose we start from one possible position and have 2 different moves to choose from. After 8 moves we would have 2^8=256 possible games, if they do not overlap, and 1+2+4+8+16+32+64=127 possible positions. In chess the branching is about 3.) So we can say that the number of sensible positions is about the same as the number of sensible positions estimated to 10^40.

So the probability that a totally random position you set is sensible one as well is roughly 10^-30, or should I say it is close to impossible of doing it randomly.

One thing that would be quite interesting to know is how many groups of connected positions legal or illegal we have in chess. Connected means that you can reach one position from another. Nobody cares about these things, but we are not going to resolve chess in mathematical sense if we do not start asking these questions.

---
Tags: analysis, programming, retrograde-analysis, calculation, chess-algorithms
---


# Question
Title: Ideas to keep in mind before a tournament
Tomorrow I'm playing in my third OTB tournament. I have tried coming up with really long chess "acronyms" to try and remember all the different things I need to consider before my move but they become so elongated and tedious I end up mentally ditching them and just more so start "playing from the hip."

That said my thought process is really simple:

(1)During my opponents move: Scan the board for all undefended pieces and pawns, giving a slight emphasis to MY pieces and pawns. Afterwards consider any moves that could potentially protect them and possibly add protection to another piece/ key square simultaneously. Then I scan the board for my opponents undefended pieces and pawns.

(2) During my move: Ask why my opponent played his last move. What is the thought behind is move and is there a threat he can make with it soon (by using another piece in combination etc.) Weigh several candidate moves and critique them. Does my move leave a key square or other piece undefended? If I make this move won't my opponent refute it?

And that's about it. When it comes to strategical conepts like weak pawns/squares and imbalances (bishop pair/ queenside pawn majority) I haven't really fit such things into my thought process. It doesn't mean I'm not aware of such things somewhere in my mind, it just means it's not presently apart of my deliberate thought process. Which is part of the reason I'm here... to ask if it should be!

If anyone can help me out even if it is after my tournament tomorrow that would be great!

# Answer
> 1 votes
I hope you did well in the tournament, and I'm thrilled you keep going back to them! I also applaud you for trying to apply the things you are learning so quickly :)

There are a lot of things to learn - and not all of them are 'knowledge' things - how to handle the pressure (keeping score, the clock, and the competition aspect), how to accomplish SO MUCH in such a limited time, and including how to remember 'everything'.

And perhaps the most important is that this all is part of a process. I've coached children in chess for 20 years, and I also teach math, and I think most people develop accuracy before they develop speed when they are learning new things. The trouble is - it's hard to develop accuracy in the competition itself. So realize that accuracy is developed OUTSIDE the competition. The tournament is to measure where you are at that moment.

Your checklist is a good place to start - you have to begin with threats, and they will eventually become more automatic (or automatic-like). You build accuracy by studying, but it's also important to review your games afterwards. In the olden days most opponents would go over the games with you, and it's valuable to get a view into someone else's thought process. Sometimes it's downright amazing! But that can be a great way to see how the strategic and positional elements fit into the overall game. If you can't do that, try to review them with a friend and argue out different moves and lines. But you must also review your games afterwards by yourself. It's useful to have an engine handy, but try to think hard about each move and its consequences with the luxury of 'infinite' time you have after the tournament ends.

Dan Heisman's books were always good for tournament players who were starting out. He gives very practical advice about the experience of playing chess, and not just the best chess move.

Playing is important - both informally and the more formal tournaments you are beginning to play. Spend some of your home learning time too by looking at games as if you were playing them in a tournament. Bruce Pandolfini has had a long time chess column in Chess Life called I think 'Solitaire Chess' where you play one side of a game. You probably already get Chess Life, (and this is easier if you are looking at paper) but if you need more practice the USCF recently made available an archive of MANY YEARS of Chess Life: https://new.uschess.org/chess-life-digital-archives

Good luck! And I wish you many decades of enjoyment tackling the game!

---
Tags: strategy
---


# Question
Title: Where can I download chess games from a specific position into a PGN file?
Is there a website that will let me search for master-level games from a specific chess position and download them into a PGN file for free?

# Answer
Sure - I imagine there are quite a few. Here's one: https://www.365chess.com/

1. Expand Resources, and click on Board Editor
2. Clear the board, and set up whatever position you want. Make sure you state which side is to move, and whether castling is available still ...
3. Below the board copy the FEN of the position
4. Expand Search, and click on Game position
5. Choose whether to search in the Openings Explorer or Games Database
6. Click on Import FEN, and Paste in the FEN you copied from your position. Click Load
7. Click on Search!

I think you have to create an account (it's free) to download PGNs, but many of the sites work similarly.
> 1 votes

---
Tags: opening, pgn, websites
---


# Question
Title: Why is the definition of check not circular?
If you want to determine whether a player is in check I think you would:

1.1) determine every legal move of the opposition;

1.2.) determine whether such a move threatens our king (i.e. could 'take' the king)

To determine 1.1) above you need to:

2.1.) consider every active piece of the opposition and its possible moves;

2.2.) see whether that move conforms to a valid type of move (i.e. moves likes a castle,knight etc)

2.3.) confirm that such a move doesn't place the opposition in check (otherwise it's not a valid move)

Yet 2.3 requires us to go back to 1.1-in order to determine whether the opposition's move is not check (and thus valid) we need to consider all the possible moves of our side (the side which we wanted to determine if it was in check originally).

It seems that this leads to some horrible circular dependency. Obviously, it doesn't as otherwise chess wouldn't be a game!

Where am I going wrong?

# Answer
A move can be illegal because the opponent could "take" the king. This "taking the king" move does not need to be "legal". See Can a piece pinned to my king put the opponent's king in check? and Is the king actually in check if the attacking piece cannot be moved?
> 11 votes

# Answer
Generally speaking, the most "expensive" part of chess programs is generating all legal moves from a certain position. Anything that can be done to avoid that is usually done because it speeds everything up significantly.

In order to find out whether a move is check or not, you can do several relatively simple checks (all of these are simple addition in most board coordinate systems).

1. See if the king is a rook's move away from enemy rooks or queens
2. See if the king is a bishop's move away from enemy bishops or queens
3. See if the king is a knight's move away from enemy knights
4. See if the king is diagonally adjacent to enemy pawns

By changing the thinking to start with the king's position, it makes some of these determinations far more simple. Another note is that most programs have an explicit variable set for the king's position because it's used quite frequently and there is always a single king for each side.

As a note, this same routine is called to see if a piece is pinned when generating legal moves. After the move is "made", if the friendly king is attacked then the move was illegal.
> 5 votes

# Answer
You say that your definition seems to be wrong because it is circular. You are right.

The part that makes it circular is step 2.3, which is required to evaluate “legal” in step 1.1. This is where you went wrong. The moves that would capture the king must be legal *except for possibly putting the opponent in check*. In other words, a piece pinned to the opponent’s king can still give check to the first player.

See the links in limits’s answer.

---

You worded step 1.2 as (emphasis added):

> determine whether such a move **threatens** our king (i.e. could 'take' the king)

This is an incorrect use of the word “threatens”. For example, in the game below, 1...e5 *threatens* 2...Qh4#. In this sense, it *threatens* the king, but is not itself a capture of the king.

```
[FEN ""]
1.f3 e5 2.g4 Qh4

```
> 4 votes

# Answer
"If you want to determine whether a player is in check", then consider each opposing unit in turn. If it observes the turn player's king, the turn player is in check. Andrew's answer goes some way to explaining how one might do this, but missed the subtlety that an enemy line-piece's line of attack on the turn player's king might be obstructed by another unit, in which case the said enemy line-piece does not give check.

This task is similar to, but not the same as, generating all legal moves for the turn player's opponent. But unlike the latter task, the former does not entail deciding whether any king is in check. This algorithm is therefore not "circular" (i.e. does not entail an infinte recursion), and implements the definition of check, which is therefore not circular either.
> 1 votes

# Answer
I think you are taking it too hard.

Why not simply think like this:

1. Simulate all possible next moves by same side
2. If, in any resulting position in simulation, king is missing(captured) go to 4
3. King is not in check, go to 5
4. King is in check
5. End

Why this works? Because if king is in check, it means if the same side plays again(plays double times) it can capture the king. So if it can capture the king by playing double moves, then it means opponent was in check.

For example, assume it's Black to move again(plays double move):

```
rnb1kbnr/pppp1ppp/8/4p3/6Pq/5P2/PPPPP2P/RNBQKBNR w KQkq - 1 3

```

Enumerate all possible moves. Now check all resulting positions, is White king missing in any position? Then it means White king was in check.
> 0 votes

---
Tags: rules, terminology, check
---


# Question
Title: How do you calculate your Tournament Performance Rating?
How do you calculate your Tournament Performance Rating?

I can think about two different ways to answer my question:

1. Do you know the formula for calculating your TPR (FIDE or USCF)?
2. Can you link me to a FIDE TPR calculator and then a USCF TPR calculator?

* I recall that rating change calculators have this TPR function.

# Answer
> 8 votes
TPR calculators and expected rating change.

http://englishchess.org.uk/Juniors/tournament-performance-calculator/ http://www.uschess.org/content/view/13146/836/

Basically Performance rating is the average of your opponent's ratings with an adjustment based on the score of the game. For each win, you add your opponent's rating + 400, a draw is just your opponent's rating, and a loss is your opponent's rating - 400. There is an exception for a perfect score, then the adjustment is 800.

# Answer
> 7 votes
Section 1.48 of the FIDE Title Regulations effective from 1 July 2017 specifies how the performance rating is calculated. The average rating of the opponents is adjusted by a value determined by looking up the percentage score in a table.

For example, after Round 12 of the 2018 Candidates Tournament, Ding Liren had 6.5 out of 12 points, for a rounded percentage score of 54%. According to the table, this corresponds to an adjustment of +29. The rounded average rating of his opponents was

(2763 + 2 * 2794 + 2 * 2809 + 2 * 2767 + 2 * 2784 + 2 * 2799 + 2800) / 12 ~= 2789,

so his performance rating at this point was 2789 + 29 = 2818, as you can see in this screenshot:

# Answer
> 1 votes
This answer spells out the actual calculation of performance rating for USCF tournaments, as in the June 2017 Rating Estimator that Fred Knight's answer points to. If you view the page source at that link, the calculation is given in the form of the code for the `performanceRating` function.

Aside from details about whether one has an established rating and such, the basic calculation that it performs for an established player is as follows:

1. When a player with rating `playerRating` takes on an opponent whose rating is `opponentRating`, her expected score for the game is given by the formula `1 / (10^(opponentRating - playerRating) / 400) + 1)`, which will be a number between 0 and 1.
2. The `performanceRating` function makes a guess at the `playerRating`, and sums up the results from step 1 across all the games entered for the player. That sum is the total score a player with that rating would be expected to get against the listed opponents.
3. Depending on whether the total expected score from step 2 is higher or lower than the player's actual tournament score as entered in the estimator, the `performanceRating` function iteratively adjusts its guess up or down as needed until it narrows in on the `playerRating` value that yields an expected score that matches the actual tournament score. That is then the player's *performance rating* for the tournament.

In case anyone wants something less opaque than the estimator's source code, here is a Google sheet that allows one to enter opponent ratings and total tournament score as in the USCF estimator, and then iteratively guess performance ratings manually. You should find that the performance rating result matches that of the estimator (again, at least in an ordinary situation not among the various exceptions that the estimator's `performanceRating` function deals with).

---
Tags: rating, tournament, mathematics, performance
---


title: Which are better, Knights or Bishops?

text:
# Question
Title: Which are better, Knights or Bishops?
I have always thought Bishops were better - I know that a KBB vs. K endgame is easily won, whereas KNB vs. K is difficult, and KNN vs. K is impossible; but then again, some people prefer Knights. I realize there is a reason for each receiving the same point value (3) - they are so similar in strength, the Bishop on open lines and the Knight in close quarters.

But is there any concrete study on the point, such as someone analyzing thousands of games in which one player began the game with two Bishops and no Knights, and the other had two Knights and no Bishops?

# Answer
> 12 votes
It depends on the board position. Both have equal points. But in a closed position, i.e, when the mobility of our pieces are blocked by the opponents pieces, knights have advantage. On more open board positions, bishops have advantage.

# Answer
> 8 votes
Usually in open positions the bishops are better. When the position is blocked up the knights are generally better. In an endgame with pawns only one one side of the board, the knight is usually better. In endgames with asymmetrical pawns on both sides of the board, the bishop is usually better. With a symmetrical endgame pawn structure you might like the have the knight and place your pawns on the opposite color of the opponent's bishop. Possessing the 2 bishops is also generally overrated and I have not really seen anyone \< 2000 USCF really able to finesse the position to take full advantage of that.

Remember all these are general principles and the specific position must be evaluated always before general considerations.

# Answer
> 5 votes
None of them are "better" in a general sense, but they are different. As bishops are long-ranged and can theoretically control more space than a knight (up to 13 squares against 8), they tend to become more powerful in situations where there are open diagonals (space-aspect) or during endgames when pawns are at both sides of the board (long-range-aspect). On the other hand, knights have a great maneuverability, can attack more different pieces without being attackable from them in return and support pieces with different movement rules very well (like attacking the same spot, but from a different square). So they are different tools, becoming very powerful or useless depending on the board situation.

Your question can't be answered generally. You could ask as well, whether a spoon or a fork is the better eating tool. It all depends on whether soup or chips is the dish of the day ;)

# Answer
> 4 votes
Steve Mayer wrote an excellent book on the subject, Knight versus Bishop: The Verdict. You could do worse than have a look at that. It explains the circumstances under which one is better than the other, and the fact that he wrote a well-regarded book about the topic suggests that it's not easily addressed in a forum reply.

# Answer
> 1 votes
My answer comes years late but differs from the others.

A bishop can often reach a square from which it can control, restrict or bind an opposing knight. See the diagram, which gives an unspectacular but typical example.

```
[fen ""]
[startflipped "0"]
[startply "58"]
[title "S. Mamedyarov v. M. Carlsen, Wijk an Zee, 2018"]

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.cxd5 Qxd5 6.e3 c5 7.Bd2 Bxc3 8.Bxc3 cxd4 9.Bxd4 Nc6 10.Bc3 O-O 11.Nf3 Rd8 12.Be2 Qe4 13.Rc1 Qxc2 14.Rxc2 Nd5 15.Ne5 Bd7 16.Nxc6 Bxc6 17.Bd2 Ne7 18.f3 Rac8 19.e4 f6 20.Be3 a6 21.Kf2 Bb5 22.Rhc1 Rxc2 23.Rxc2 Bxe2 24.Kxe2 Nc6 25.b4 Rc8 26.Rc5 b5 27.f4 Kf7 28.a3 Ne7 29.Rxc8 Nxc8 30.Bc5 Ne7 31.Bxe7 Kxe7 32.Kf3 Kd6 33.Ke3 e5 34.f5 Ke7 35.g4 Kf7 36.h4 Kg8 37.Kf3 h6 38.h5 1/2-1/2

```

White moves 30.Bc5. In this particular game, Black is Magnus Carlsen, so Black has foreseen the trouble and has advanced his king into a position from which the king can help to rescue the knight from its bind. The point, however, is that the knight is indeed in a bind. The bishop has done this to the knight.

Admittedly, knights can take away squares from bishops, too, but a bishop can often escape by advancing past the knight out of the knight's range. On average, bishops have the upper hand over knights in positions like these.

Nor are positions like these rare. Such positions are common, in fact. Indeed, such a position occurs again earlier in the same game. (Easy exercise: find the position. The same white bishop restricts Black's *other* knight for six full moves.)

This bishop-versus-knight dynamic, in which the bishop has slightly the better of the struggle, is a significant reason to regard the bishop as being—on average—slightly stronger than the knight.

The knight can of course reach all squares of the board. This is a significant point in the knight's favor, but the bishop has other, subtle advantages. For instance, a bishop can three-step.

Consider: a knight can move away from its square and back in two moves but, interestingly, cannot do so in three moves. A bishop by contrast can indeed use three moves to return to the square from which it starts. In an endgame, this three-step dynamic can allow the player with a bishop to put his opponent, who has a knight, in *Zugzwang.*

There is also the bishop pair. One of the other answerers opines that non-expert players can seldom effectively use the bishop pair. Actually, there is some truth in that opinion, but I have (occasionally) seen non-expert games decided by a pair of bishops, so you have that factor to consider as well.

On the edge of the board, bishops are often happier than knights.

A bishop and a pawn can mutually protect one another—yet, with a quick push of the pawn, the position can be converted into one in which the pawn covers squares of one color and the bishop squares of the other.

All factors considered, on average, the bishop is probably very slightly the better piece. But yes, of course, as others have pointed out, it depends on the specific position at hand.

# Answer
> 0 votes
We could definitively answer this. You'd use Shapley Values and simulation with Stockfish to reveal the value of the various pieces. You'd have to think about how to set up the simulations, if you'd only simulate games from starting positions, removing 1 or 2 knights or Bishops, but basically it's a quantitative question which could be answered.

Intuitively, I'd rather have one knight and one bishop than no knights and both bishops or vice versa. This could also be tested, and various other conditions, via simulation.

---
Tags: knights, bishops, minor-pieces
---


# Question
Title: Understanding when it's OK / not OK to trade off the fianchettoed bishop
In this position:

```
[FEN ""]
1.e4 g6 2.d4 Bg7 3.Nc3 c6 4.Bc4 d6 5.Nf3 Nf6 6.O-O b5 7.Bb3 b4 8.e5 bxc3 9.exf6 Bxf6 10.bxc3 O-O 11.Bh6

```

According to the lichess database, the most common move here for Black is `Re8`. However, the engine says `Bg7` is the best move, and both games in the Masters database in this line continue with `Bg7`.

Can someone explain the logic to me of why Black would want to trade off his fianchettoed defender here? Isn't that something you normally want to avoid, since it would weaken the dark squares around his king?

---

On a related note, I've also come across this position while playing the King's Indian Defense:

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 Nf6 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. Be3 Ng4 8. Bg5

```

The first time I saw this position, my instinct was to play `Bf6` since my bishop is pretty horrible compared to White's, being blocked in by all of my central pawns. However, this just loses a pawn after `9.Bxf6 Nxf6 10.dxe5`. My question is, would it be desirable for Black to trade off the bishops if doing so didn't lose a pawn? e.g. In this position:

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 Nf6 4. e4 d6 5. Nf3 O-O 6. Be2 Nbd7 7. O-O e5 8. Be3 Ng4 9. Bg5

```

Why is `f6` still more common than `Bf6`?

# Answer
> 3 votes
In the first position you mentioned, I'm guessing the reason why the engine recommends Bg7 is because Re8 weakens the f7 pawn, which could conceivably get loose later on.

In the last position, before your last line I was going to say that I liked f6 there rather than Bf6. I'm not completely sure why, but I think the reason is that the bishop is awkward on f6. It's blocking your f-pawn, and also stranding your knight on g4, which is now trapped. I don't immediately see how white can take advantage of it, but doesn't seem harmonious.

It seems like you're trying to look for general rules. Chess is a very concrete game and what is best depends on the specific position. There are some good general principles, but not a whole lot.

# Answer
> 4 votes
A weakness is only a weakness if it can be tortured by the opponent.

In example 1, White has already castled, so Re1-e4-h4, Q-d2-h6 seems to be the only way to bring on some scary firepower against the king. Also, the Pe7 still protects f6, so at least not a double weakness (Ph2-h4-h5-h6, Qf6 would be otherwise the standard plan). Still, the computer yawningly played e6 (to make the white bishop completely look on granite), h6, Rh8, already with a -1 advantage for black.

Concerning the KID black bishop, the KID is only becoming really KID-ish as soon as White plays d5. Good luck *forcing* White to d5 without this bishop! (It would be interesting to set up a position with the classical f4 attack of Black, remove the two dark-colored bishops and compare engine judgment, but I'm too lazy...)

To mock a famous saying, bad bishops have good later-on uses.

---
Tags: strategy, fianchetto, trading
---


title: Is triple check possible?

text:
# Question
Title: Is triple check possible?
In my logic, triple check not possible. Because I assume there is a move with two pieces at once needed. The only move I know is castling. The King can not give a check. So is triple check impossible?

# Answer
> 22 votes
Triple check is impossible, unless you want to count an x-ray attack as the third check. A queen and rook attacking on the same file is normally thought to be one check.

# Answer
> 21 votes
To look at this systematically, let's say white is attempting to triple-check black.

At the start of white's move, black's king is not in check. So we have to go from zero checks to three checks.

When a piece moves:

* the previous square it occupied becomes vacant (possibly creating a discovered check)
* the target square becomes occupied (possibly creating a check from this new position).

These discoveries are possible:

* Pawn, knight or king moves: discovery by bishop, rook or queen.
* Bishop moves: discovery by rook or queen.
* Rook moves: discovery by bishop or queen.

That only leads to two checks. (One unoccupied square can't cause two discovered checks because there is only one rank/column/diagonal between the king and that square).

What other options exist? Do any of the special-case moves support a third check?

### En passant

This causes *two* squares to become vacant – the square that our pawn moved from, and the square that contained the enemy pawn. So two discoveries are theoretically possible. Could this work?

For a triple check, the king would have to be in the same file as the attacking pawn's starting position (to allow for discovery by a rook or queen), and on the 7th rank (to allow for check by the pawn as it reaches the 6th rank).

For example, if white plays gxf6, black's king must be on g7. We have a position like this:

```
8/6k1/8/5pP1/4B1Q1/8/8/5K2 w - - 0 1

```

When the pawn captures, it opens up a discovered check along the g file. You can see that the removal of the black pawn cannot create a discovered check, as it is positioned a knight's move from the king, neither on a file, rank or diagonal.

Alternatively, if the king was at g6, then the en passant move would create two discovered checks: the queen and the bishop. But it would not also be checked by the pawn.

So, en passant can achieve:

* two discovered checks; or
* one discovered check, plus one regular check by the pawn;
* but not two discovered checks plus a regular check by the pawn

### Castling

Castling causes two pieces to move at once, which sounds promising. But one of those pieces is a king, which can never give check, so it doesn't help. And since the rook starts from A1 or H1, it can never give a discovered check in the process, either.

So, at best, castling yields one check.

### Promotion

Pawn promotion sounds superficially interesting, but it's essentially like a normal move, that happens to start like a pawn and end like a queen or similar: a square is vacated, a square is occupied. Two checks are possible.

### Double pawn move

The ability of a pawn to move two squares doesn't help: it's still vacating one square and occupying one other.

### Conclusion

No, there is no way that three checks can be delivered with a single move in normal chess.

# Answer
> 12 votes
Triple check is possible in , aka chinese chess. There is even the possibility for quadruple check.

> Unique to xiangqi is a triple check, which arises in three combinations. In the first case of a cannon, a chariot or soldier, and a horse, the horse moves to give check, uncovering a double check from the chariot and the cannon. In the second, rarer case of a chariot or soldier and two horses, the chariot moves to give check, uncovering a double check from the two horses. In the third case of two cannons and two horses, one cannon may uncover a double check from the horses and act as a screen for the other cannon. Quadruple check is also possible, arising with two horses, a chariot, and a cannon. Triple and quadruple check cannot be blocked.

Source: wikipedia

# Answer
> 11 votes
Triple check is possible in the chess variant known as Cylinder Chess. In this position, 1.Ra8 discovers check from the queen and bishop, so it's triple or maybe quadruple check, depending on whether you count one or two checks from the rook, which is attacking the black king from two directions.

```
[FEN "4k3/8/8/8/R3K3/8/8/3Q1B2 w - - 0 1"]

1. Ra8+

```

# Answer
> 3 votes
No.

Even if you could like take a pawn en passant and open up two lanes in 1 move, only 1 lane will be mathematically relevant to checking the king.

See, you can attack the king from a ton of directions, but all checking moves can mathematically only make 1 or 2 lanes/diagonal opened and thus relevant for delivering a check.

Chess notation for diagrams use + for a single check and ++ for a double check, but I've never seen a +++ character for a triple check. They simply don't exist.

# Answer
> 3 votes
The check itself defined as a player's king is under threat of capture by attacking piece(s) on next opponent's turn. According to standard chess rule, the pieces which can be counted as checking the king are pieces which **able to move directly to the king's square.**

These conditions counted as double check instead of triple check, assumed the pieces are attacking in one move:

1) Rook battery with queen/bishop/knight/pawn (second rook at the same file/rank not counted).

2) Queen-bishop battery with rook/knight/pawn (whoever supporting piece at the same diagonal not counted).

These conditions counted as single check instead of double:

1) Queen-rook battery (or two rook battery).

2) Queen-bishop battery.

Also, **triple check is impossible in standard chess** due to *multiple checks must be executed in only one move*, which allows maximum of 2 pieces capable to attack the opponent's king directly at the same time (attacking pieces are neither subject to be captured nor interposed by other opponent's pieces).

# Answer
> 3 votes
As others have pointed out, triple check is never *legal* in chess. It is, however, *possible*, even though no possible triple check is legal.

One context where this is relevant is in framing the rules of the game. The rules must be written so as to enable the reader who does not yet know what is legal, to learn this. In this answer, Brian Towers details a deficiency which at one time existed in FIDE's Laws of Chess which allowed triple check. (It's since been corrected.)

Another such context is in writing a program which, given a chess position, generates all legal moves from it. A candidate must be rejected as illegal if it leaves the turn player's king in check from *at least one* enemy unit. It is possible that there are three, viz if the turn player is in double check and moves a pinned unit.

# Answer
> 0 votes
If you are to check a king, that can be caused by the figure you are to move or just by moving the same figure.

A figure that you are to move can check the king in only one way depending on the piece you are moving. The connection between a position where you are to move it and the position of the king is 1:1: they are on the same diagonal, row or column, or it is a knight attack.

A figure that you are to move can reveal a check, but then again the revealed figure is attacking the king in one way only. Since there is no knight or pawn chess that can be revealed all other checks are by revealed diagonal row or column, and that means it is the first and one figure on one specific diagonal row or column that can attack the king. So it can be only one figure that is attacking the king by revealing the attack.

On top of that, by the rule of chess, no figure can attack another figure in more than one way. An attack is simply: one position where a figure of opposite color could move next if the position were not already occupied.

So at worst a king can be attacked by revealed check and direct check at the same time after you move a figure. That is making it double check at most. Otherwise third check would have to be already there before you make your next move and that is not allowed or not even possible if it is a checkmate when the game is over.

---
Tags: theory, check
---


# Question
Title: Is there an engine evaluation technique that factors in 'time'?
An interesting game played out between Wesley So and Levon Aronion1:

```
[title "Wesley So vs Levon Aronian"]
[fen "rn4k1/p2bP1b1/2q5/1pp2p1Q/2p5/8/PP3PPP/3R1RK1 w - - 0 1"]

```

So was in a far superior position according to the computer, *but* had only about 1 minute compared to Aronian's 5 minutes.

Is there any established system for evaluating positions ***taking into account time for both players***?

1 Link to game: https://www.chess.com/events/2021-magnus-carlsen-invitational-prelims/06/So\_Wesley-Aronian\_Levon

# Answer
> Is there any established system for evaluating positions taking into account time for both players?

No, there isn't. This is for two main reasons:

1. There is no objective measure for how time affects a player's ability to play any given position.
2. Such evaluations would be useless. They would literally tell you nothing useful

Let me give an example from a game one of my clubmates (rated about 1800 at the time) played a few years ago in the UK National Universities Championships.

In the blitz section (3+2) in one of his games he reached a KBN vs K endgame with less than 30 seconds left on the clock. He knows that endgame (he has a strict coach who makes him learn that kind of stuff) and so blitzed out the win with plenty of time to spare on his clock.

I also have stronger clubmates (2100+), however, who don't know that endgame. They would never be able to mate in so little time. Give them 20 minutes on the clock and maybe they'd succeed. There have even been IMs who have failed with plenty of time on the clock.

Bottom line: even with as simple a position as this there is no way to provide a meaningful evaluation of the position that takes time into consideration.
> 20 votes

# Answer
Time is implicitly added to any position analysis, but not in the way you would expect. All algorithms stop at either certain depth or time consumed, or memory, processor... consumed or the combination of these. It stops when it is predicted that it would need more time than what you have on your computer, some Web site server, or generally when it is obvious that the resource consumption will start increasing beyond acceptable level (for example exponentially). Sometimes it just stops as further depth analysis shows no promising result.

Then a computer will stop and give you the estimate.

That is how it is working. So the best way of mimicking your situation is to let computer play against itself with the time that you have. A computer is totally aware of the time left, and it will reduce analysis in order not to lose on time. But you cannot strictly evaluate the position based on that. The only way is to restrict the computer itself while playing.

Usually I do this more than once, but not too many times, in order to get some sort of feeling of what human would do in that position with the same time restriction. If you do a full analysis and this reduced analysis, you can almost always see that a computer is crippled, but not in the same sense as human. You need to play a little bit more around to mimic what human could come up with on short notice. You do get the feeling over what is not immediately visible and what line looks tempting, but it is generally wrong. Of course, it says to you nothing how human would play, it is telling you generally what you could expect a player to fall for if he is under pressure.

Computer and human play different game and reducing time has a quite different effect. Still, you can get some real feeling over how human would play a similar position if you let a computer play the same position couple of times (and try to erase its learning mechanism in between if there is such thing implemented).

Evaluation with time restriction is possible, and all computers in the world must restrict this. But it is not the same as restricting real time for a chess player.

What you need to do in order to get a feeling about the position complexity is to track computer analysis. More and longer it is jumping before reaching a stable evaluation, it is more likely that a position is complex for human to quickly analyze when under time constraint.
> 2 votes

---
Tags: engines, evaluation, time-control, wesley-so, aronian
---


# Question
Title: When playing a two-game match, is it better to have white in the first game?
Many rapid and blitz tournaments use a multigame match system in the elimination rounds. What statistics are there on how frequently the player with White in the first game wins? Is there a statistical advantage to playing white in game 1 of a two-game match of chess?

Assumptions:

* You play with the other color in the second game.
* The margin of victory does not matter. What counts is if you win, lose or draw the match.

# Answer
> 8 votes
The question is somewhat interesting, so I gathered some data to see if the player who first has White has an advantage.

The Chess World Cup is an ideal tournament to test this hypothesis. This tournament consists entirely of two-game matches. After a 1-1 tie, two-game rapid and blitz matches are played, but I did not include those in the analysis. Below, I analyze the inaugural 2005 World Chess Cup.

After scraping all 286 classical games from the FIDE website and putting them in a useful format, I randomly split them into two groups. Half of the players had the White pieces in the first game, and half started with Black. A player can obtain 0, ½, 1, 1½, or 2 points (let's call it the player's *score*).

A one-sided t-test for the mean showed no evidence for a difference between the average number of points obtained between the two groups (p = 0.402, df = 141). Furthermore, whereas the rating difference was highly significant in predicting a player's score (p = 0.000), who played White in the first game didn't matter (p = 0.735). (Technically, predicting the outcome of a match is a classification task, but OLS regression on the number of obtained points seems like a reasonable approximation.)

There are two caveats. First, the games played at the World Cup are of a high level: for amateur games, the advantage may differ. Second, I have only considered classical games. So perhaps the results will not generalize to rapid and blitz tournaments, though I am unsure why they wouldn't.

---
Tags: statistics
---


# Question
Title: Is there any website that shows which opening a certain player struggles against?
I just thought that it would be an interesting statistic to know which openings players like Carlsen and Fischer lost most against. Are there any websites that give these statistics?

# Answer
> 7 votes
Opening tree happens to be the website you are looking for. Using this, you can use a database of games or someone's Lichess or chess.com username to get detail about their games. It shows frequency, last played, best win, worst loss, win-loss stats and performance. It also have have fatabases of famous players in it. Checking Anand's games as black, after playing `1.e4 2.c5 3.Nf3` his worst performance is in Sicilian Defense: French Variation (elo performance 2644) with score 107/173 and worst loss was Ljubojevic - Anand 1998.

Overall, it's a nice free website.

# Answer
> 0 votes
lichess.org has also this kind of tool for open profiles. I guess this tool is used or can be used for external chess websites. Probably, someone can find the open-source code of chess-insights tool in lichess-github repo. Read more about chess-insights here

---
Tags: opening, statistics, websites
---