Chess rules question

[Kevin Pacey]

I have a question about the rules of chess that someone might know the answer to offhand. If 50 moves have elapsed without a capture or pawn move, yet the 50th move played is a checkmate, is the result a draw or a win for the side delivering mate?

[Ken Craft]

Re: Chess rules question

Win, I would think.

[Kerry Liles]

Re: Chess rules question

I have a question about the rules of chess that someone might know the answer to offhand. If 50 moves have elapsed without a capture or pawn move, yet the 50th move played is a checkmate, is the result a draw or a win for the side delivering mate?

Once a move is completed that ends the game, I don't see an opportunity to claim a draw... :)

[Hugh Brodie]

Re: Chess rules question

If it's White to move and give mate, and Black has only played 49 moves, he can't claim a draw in any case. If Black gives mate, it's too late for White to claim a draw - but he could claim verbally before completing his 50th move and pressing his clock. The moves would have to be verified - it's either a draw, or not a draw and Black can play his mating move.

[Egidijus Zeromskis]

Re: Chess rules question

If it's White to move and give mate, and Black has only played 49 moves, he can't claim a draw in any case. If Black gives mate, it's too late for White to claim a draw - but he could claim verbally before completing his 50th move and pressing his clock. The moves would have to be verified - it's either a draw, or not a draw and Black can play his mating move.

It's depend who captured the last. If White, then we start counting Black as first.

The mate ends the game. Thus, the claim should have been done before that if there was ground for that.

9.3
The game is drawn, upon a correct claim by a player having the move, if:

he writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his intention to make this move which will result in the last 50 moves by each player having been made without the movement of any pawn and without any capture, or
the last 50 moves by each player have been completed without the movement of any pawn and without any capture.

[Pierre Denommee]

Re: Chess rules question

A 50 move draw is not automatic, it must be claimed by a player. If White has the move and can deliver checkmate, he has no valid reason to claim and the mate is good. Black cannot claim because he does not have the move.

9.4 If the player touches a piece as in Article 4.3, he loses the right to claim a draw under Article 9.2 or 9.3 on that move.

If black did not claim, he can no longer claim after touching a piece.

[Paul Bonham]

Re: Chess rules question

Once a move is completed that ends the game, I don't see an opportunity to claim a draw... :)

Ahhhh... but DOES it end the game? That is the question Kevin is asking.

The move, being the 50th move made by both players since the last pawn move or capture, fulfills the requirement for a draw by the 50 move rule. It also simultaneously fulfills the requirement for ending the game only because the side that is to move (i.e. the side that has the move) has no legal move remaining.

But does the side to move have to have a legal move remaining? S/he has the move and the conditions for draw for 50 move rule have been fulfilled. So rather than make a move (which s/he can't), why can't s/he claim the draw? In essence, claiming the draw IS the move. Thus that player does have a legal move: to claim the draw.

In draw by 3-time repetition, the game can be drawn using perpetual check. Thus the game may end with one side's King in check, and it ends a draw. This is precedent for allowing Kevin's scenario to be claimed as a draw.

In a lighter look at this....

As you read the following, pretend you are hearing it straight from Eric Idle.... if you don't know who Eric Idle is, here is a link to his great documentary work:
Eric Idle Documentary

Ok, here goes.....take it away, Eric.....

"This is an area of deep mathematical research. At the very instant the hand leaves the piece, which move is completed: the checkmating move, or the 50th move with no capture or pawn advance? Which way does the wave function collapse?

The problem is that to make experimental observation, a genuine game that meets the conditions must occur, and when it does occur, it must be scientifically observed. The two participants cannot play into this situation by mutual agreement. To do so would be to color the result with human subjectivity. So instead, the state must come about by pure random chance.

Rumor has it that in secret labs deep in the Colorado mountains, the most drawish, non-piece-capturing, non-pawn-advancing players chess has ever produced are held, forced to play game after game for days, weeks, months on end to try and create the conditions necessary. Special digital meters have been constructed, and their LCD displays are capable of reading instanteously the quantum state surrounding the chess board and registering either "1-0" or "0-1" (meaning checkmate for White, Black respectively) or "1/2 - 1/2" meaning draw. There were rumors that Canadian Doug Burgess was once taken to this secret research lab, but his memories may have been altered -- the only trace of what he may have been put through comes when he reaches to move a pawn and receives a "phantom jolt".

Apparently all this research has yet to yield a defnintive answer to the perplexing question.

In quantum mechanics, wave function collapse is said to occur when a wave function — initially in a superposition of several eigenstates — appears to reduce to a single eigenstate (by "observation"). Before collapse, the wave function may be any square-integrable function. This function is expressible as a linear combination of the eigenstates of any observable. Observables represent classical dynamical variables, and when one is measured by a classical observer, the wave function is projected onto a random eigenstate of that observable. The observer simultaneously measures the classical value of that observable to be the eigenvalue of the final state.

Perhaps then it is best to separate out these results by putting "eigen" in front: either an "eigenwin" or an "eigendraw".



BTW.... did you know that the Monty Python troupe predicted the rise of the internet? And especially ChessTalk?

Monty Python Predicts ChessTalk

[Mathieu Cloutier]

Re: Chess rules question

Guys, who forgot to bring mr. Bonham his medication? Who's turn was it this week?

[Kevin Pacey]

Re: Chess rules question

Thanks for the answers. Pierre's reasoning is particularly clear to me.