69
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Why is there a 50-move rule and a 75-move rule?
From the FIDE Laws of Chess:
50-move rule:
9.3 The game is drawn, upon a correct claim by a player having the move, if:
(...)
the last 50 moves by each player have been completed without the ...
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19
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Identify a problem where a potentially winning move draws because of the 50 move rule
There are dozens of problems that illustrate a potential winning moves that instead leads to a draw because of the 50 move rule.
One example is the following mate in four published by Léon Loewenton ...
- 813
19
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A 50-move-rule claim turned out to be incorrect - can the arbiter punish me?
Yes
According to the FIDE Laws of Chess
9.5.3 If the claim is found to be incorrect, the arbiter shall add two minutes to the opponent’s remaining thinking time. Then the game shall continue. If the ...
- 99.9k
13
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Is it OK to look at the list of played moves during the game to determine the status of the 50 move rule?
The rules for this and how it works are spelled out in articles 9.3, 9.4 and 9.5 of the FIDE Laws of Chess. They don't mention whether or not you are allowed to check your scoresheet to do this ...
- 99.9k
13
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The 50 moves game
I have managed 106 single moves (see below).
As OP notes, if 12 pawns promote, capturing the other 4 pawns, then all captures by officers must be on 1st/8th ranks. So that would be 88+26=114.
Can this ...
- 13.4k
12
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What is the order of actions in chess under FIDE rules?
The FIDE Laws of Chess provide some guidance.
Rule 6.2.1 says you must move the piece before hitting the clock:
During the game each player, having made his move on the chessboard, shall stop his ...
- 19.9k
12
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Why is there a 50-move rule and a 75-move rule?
Although the responses all were intended to answer the question, they all fell slightly short. The 75-move rule was implemented so that an arbiter could adjudicate a game as drawn in a clearly drawn ...
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11
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Can Loss by Checkmate be Avoided by Invoking the 50-Move Rule Immediately After the 100th Half-Move?
Can player B invoke 9.3.2 to avoid the loss by checkmate?
No.
A player can only invoke the 50 move rule if the game is still being played. Checkmate ends the game. Once the checkmate is on the board ...
- 99.9k
10
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If both sides move at random, but legally, then how many games will be a win for White or Black, if not a draw?
The number of games is huge but finite, and estimates have been made based on a number of assumptions. But that question has been asked before already, so I won't go into the details here. A short ...
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10
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50-move rule: FIDE wording seems weird
Hi thanks for the question!
Yes this is what FIDE are saying. If you are about to play the 50.0th move of the sequence, or to cause a position to occur for the third time, then you need to claim ...
- 13.4k
10
votes
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What happens in a King-Rook vs King-Bishop with a perfect play in a no pawn endgame?
See Pawnless Chess Endgame on Wikipedia:
Rook versus a bishop: this is usually a draw. The main exception is when the defending king is trapped in a corner that is of the same color square as [their] ...
- 28.3k
8
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Simltaneous checkmate and draw claim on the 50th move
The Laws of Chess say:
9.3 The game is drawn, upon a correct claim by the player having the move, if
a) he writes his move on his scoresheet and declares to the
arbiter his ...
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8
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Proof of irreversibility of 50 move rule
The two irreversible moves can be proved irreversible (it is impossible to replicate that board state later in the game) like so:
Assumptions:
- Pawns can't move backward.
- Every pawn move moves ...
- 179
8
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Is a forced draw by 50 moves possible with Bishop and Knight endgame?
It takes at most 33 moves to win this endgame from any position (excluding positions where bishop or knight can be captured). See https://en.wikipedia.org/wiki/Bishop_and_knight_checkmate and ...
- 20.9k
7
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If both sides move at random, but legally, then how many games will be a win for White or Black, if not a draw?
It would seem that the longest games would end up being the most numerous, by far. On any particular move, if you end a game, that's one game, but if you let it continue, it's many games. It would ...
- 19.9k
7
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50-move rule: only the last 50 or any consecutive 50?
She can claim a draw. Article 9.3 of the FIDE Laws of Chess, 2018, emphasis mine:
9.3 The game is drawn, upon a correct claim by a player having the move, if:
9.3.1 he writes his move, which cannot ...
- 28.4k
7
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How long can a player hold off a draw by the 50-move rule?
The answer is trivially the starting position -
[fen ""]
This exact question hasn't been asked before (I think) but it has been answered here. Here is the relevant part of that answer -
...
- 99.9k
7
votes
When was the last time a chess rule was modified?
The rules get reworded & shuffled around every few years but it’s rare there’s substantive changes.
As far as I know, the last three significant changes that affected things were all presided over ...
- 13.4k
6
votes
Why doesn't castling reset the 50 moves rule?
I don't know the reason, but I can make a guess.
In standard algebraic notation, it's fairly easy to look at a scoresheet and see whether a capture has been made or a pawn moved. Captures have an "x"...
- 19.9k
6
votes
Accepted
How long can a player hold off a draw by the 50-move rule?
I interpret the following
White will play as long as possible, and not want to lose. Black will claim a draw as soon as possible, if not win
as meaning that Black does not help (i.e., Black tries to ...
- 901
6
votes
What is the need for repetition rules given the 50 & 75 move rules?
are the (optional) threefold-repetition rule and the (mandatory) fivefold-repetition strictly necessary?
Yes, they are necessary. Something which players sometimes forget is that arbiters are people ...
- 99.9k
6
votes
When was the last time a chess rule was modified?
When was the last time a chess rule was modified?
The last time was in January 2023. You can see the latest version here.
In general FIDE aims to update the rules every 3 or 4 years, usually after ...
- 99.9k
5
votes
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Simltaneous checkmate and draw claim on the 50th move
I would let the checkmate stand but the true answer is that it does not matter. The player has the right to offer a draw at any time and the claim according to article 9.3 is also a draw offer. You ...
- 1,169
5
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What is the source of the house-rule 18-moves?
I grew up in Spain and we used a 20 "move rule" instead of 18.
We played exactly as you said, if a player is left with a single king, the other has to mate in 20 moves or less to win the game. ...
- 3,165
5
votes
Why doesn't castling reset the 50 moves rule?
After some discussions in the comment section I think it's time for me to start answering this question to the best of my understanding. First off, let's discuss the use of the concept "the state of ...
- 8,018
5
votes
Accepted
What is the longest tablebase win that includes draw rules?
Unfortunately looking for the longest mates on Kyrill Kryukov and checking with Syzygy won't give you the answer. The mate lengths ignoring the 50 move rule don't correspond with the mate lengths when ...
- 482
5
votes
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Can a KB vs. KB endgame be declared drawn if a checkmate can occur and the 50-moves-rule doesn't apply in a Blitz game?
What is the requirement for an arbiter in the below position if one party is seriously on time trouble say 2mins against 15seconds in a blitz tournament If this party claims a draw?
If the arbiter ...
- 99.9k
5
votes
How does this problem relate to the 50 & 75 move rules?
TL;DR I think it’s just a coincidence. I don’t think that even now the composer would like to “retrofit” :-) the 75 move rule into the problem.
I’m fortunate enough to have had discussions with Tom ...
- 13.4k
5
votes
Why does the 75 move rule apply when the game have a forced checkmate?
TL;DR because unaided human players over the board are very unlikely to find the most precise lines in such critical positions.
[Title "#549"]
[FEN "1n1k4/6Q1/5KP1/8/7b/1r6/8/8 w - - 0 ...
- 13.4k
Only top scored, non community-wiki answers of a minimum length are eligible