Engine authors, beware of false-draw-claim forfeits!

Discussion of chess software programming and technical issues.

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hgm
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Full name: H G Muller

Re: Engine authors, beware of false-draw-claim forfeits!

Post by hgm »

If you send "offer draw" if the position is draw by rule, WinBoard immediately grants the draw. There is no reason to wait for a move. In two-machines mode, it would also be safe to send "1/2-1/2 { draw by rule }" here, and exit, as there is no way the game will ever continue.

If you send "offer draw" in a position that is not draw by rule, because you want to claim a draw that will occur only after the move, WinBoard can wait for your move without doing anything with the draw offer. If you don't send a move, you forfeit on time. The offer is not accepted as a claim if you don't tell first which move is the basis for your claim. The move is an essential part of the draw claim.

Looks simple enough to me...