[Retros] Thoughts about P0000743

Olli Heimo olli.heimo at luukku.com
Wed Jun 1 14:32:33 EDT 2011

Hi! I saw that there was some correspondance concerning PDB problem P0000743.
11897 is not at all an interesting number. In 1979 it was clearly written to the rules that insufficient material is an automatic draw, so the number in Bernd's problem should have been 11797. But even that number has changed during the years. About 20 years ago there were certain material combinations which allowed 75 or 100 captureless piece moves thus increasing the number of moves in Bernd's problem. More interesting is the rules change in 1997 or so, which allowed to claim for draw when it is possible to make a captureless piece move. Formulating the question like "each player must claim for draw whenever possible" the number is reduced to 11796. At the same time there appeared the rule of "dead reckoning". It means that the capture of last enemies piece is illegal. It is either a forced capture which is illegal or a voluntary capture which is also illegal because instaed of that the player had been able to claim for draw. So the really interesting number 11795. And even that is speculative, because the rules may change further like the "game is drawn if it is not possible to checkmate before reaching the 50-moves draw limit".
I published in Suomen Tehtäväniekat 6/2009 the following: Given that after black's 48th move the game was for the second time in initial position (all castling rights lost, if it has any meaning). The game continued and finally ended to stalemate with wKc1 and bKa3 and only one other piece. Question was: If the game was as long as possible then which piece and where and which was the last move? Solution: wQc4, the last move was 5898.Kc2-c1=. The last move is speculative, it could have been 5898.Qh4-c4 but then white has no possibilty to checkmate before before the 50 moves limit so we can concider it as illegal. Best wishes Olli.

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