Shouldn't this be a draw?

[AdminX]

Shouldn't this be a draw?

Rybka shows a Tablebase mate in 70 moves here. However does not the 50 move rule apply here? Yet after Black's 63rd move White resigned.

Why should the 50 moves rule apply here? White still has a knight.

Only with the lone king, 50 moves rule countdown starts.

The fifty-move rule in chess states that a player can claim a draw if no capture has been made and no pawn has been moved in the last fifty consecutive moves.

Yes, Then probably the knight capture will have taken place leading to the mate in 70 in the first position, no? Ditto for the 2nd one as well.

No, Thats the problem. There is no Knight capture within the fifty moves. You can verify this with tablebases.

[CRoberson]

Many computer chess tournaments state in the rules something to
the effect of "Once a tablebase endgame is reached, the game is over
and the tablebase evaluation is used to decide the game assuming
that one or both programs have the necessary tablebases."

As far as I am concerned, this should apply to freestyle tournaments
as well. I became rather bored in a few freestyle matches where my
opponent kept on playing. I guess he thought I'd crumble due to time
pressure, but I kept gaining time due to fast moves that I obtained from
EGTBs. Once it became clear to him that I would not lose on time
he accepted my draw offer.

[krazyken]

with best play, white will keep his knight for greater than 50 moves. White should not have resigned, the game is a draw. This is one of those cases where DTC tablebases are better than DTM tablebases.

[AdminX]

Many computer chess tournaments state in the rules something to
the effect of "Once a tablebase endgame is reached, the game is over
and the tablebase evaluation is used to decide the game assuming
that one or both programs have the necessary tablebases."

As far as I am concerned, this should apply to freestyle tournaments
as well. I became rather bored in a few freestyle matches where my
opponent kept on playing. I guess he thought I'd crumble due to time
pressure, but I kept gaining time due to fast moves that I obtained from
EGTBs. Once it became clear to him that I would not lose on time
he accepted my draw offer.

You are correct Charles, however if Comtempt was set correctly to avoid draws then the GUI would have ended the game in a draw anyway, at least the playchess GUI would have.

[Harvey Williamson]

Many computer chess tournaments state in the rules something to
the effect of "Once a tablebase endgame is reached, the game is over
and the tablebase evaluation is used to decide the game assuming
that one or both programs have the necessary tablebases."

As far as I am concerned, this should apply to freestyle tournaments
as well. I became rather bored in a few freestyle matches where my
opponent kept on playing. I guess he thought I'd crumble due to time
pressure, but I kept gaining time due to fast moves that I obtained from
EGTBs. Once it became clear to him that I would not lose on time
he accepted my draw offer.

You are correct Charles, however if Comtempt was set correctly to avoid draws then the GUI would have ended the game in a draw, at least the playchess GUI would have.

I always set the gui to resign never draw never for serious games. This wont stop it claiming a 50 move draw or 3x repetition but it will stop it resigning.

[Cubeman]

Is'nt the 50 move rule only applicable to FIDE events?

[Edsel Apostol]

"Once a tablebase endgame is reached, the game is over and the tablebase evaluation is used to decide the game assuming that one or both programs have the necessary tablebases."

I think this is a good rule. Maybe modern GUIs should support this. The GUI itself will decide if a game is already lost. It should have the complete tablebases. This way there will be no duplicate tablebases for the engines and the engine shouldn't bother implementing support for tablebases.

[Kirill Kryukov]

Many computer chess tournaments state in the rules something to the effect of "Once a tablebase endgame is reached, the game is over and the tablebase evaluation is used to decide the game assuming that one or both programs have the necessary tablebases."

I don't use this rule and don't suggest to use this rule. In my tournamens a game is decided only when there is checkmate on board. Also the entire game must be played by an engine, EGTB support in GUI is turned off.

The reason is that a significant percent of engines have endgame bugs, which go unnoticed if the games are adjudicated early. Making sure that endgame bugs (or unimplemented features like lack of EGTB support) affect engine performance should hopefully encourage release of more stable and polished engines.

[AdminX]

Is'nt the 50 move rule only applicable to FIDE events?

Not sure, but I think the answer is no. Problem is that in most chess events, professionals and amatuer tournament players alike use the FIDE rules. Not to mention these rules being programed into most chess programs.

As an amatuer player learning to play the game in New York, I found that there were two types of amatuers. Thoses that knew the rules and those that did not. I remember many arguments over games where the 50 move rule, the "touch / move" rule, or the "en passant" rule came up because the other player was not aware of these rules.

[Kirill Kryukov]

Maybe the best solution (if it can be realized) would be to use the tablebase evaluation *after* a certain number (e.g. 10) of moves have been made starting from the EGTB position, to make sure neither of the engines has an EGTB bug.

And, I'd never adjudicate a win or draw in favour of an engine that is incapable of using EGTB's. There is always the possibility that it spoils its position.

Yes this could work. Just I have seen so many different endgame bugs in engines, that I prefer to be on the safe side these days.

Hm.. Though position from the original poster is an example where this would not work. A EGTB-based adjudication (after 10 moves) would be 0-1, while without adjudication a 50-moves rule draw is more likely.