Author: Robert Hyatt
Date: 07:15:31 02/02/04
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On February 01, 2004 at 18:31:20, Ed Trice wrote: >Hello Dr. Hyatt, > >>On February 01, 2004 at 17:56:18, Ed Trice wrote: >> >>>I am wondering if Fritz has a specific evaluation routine for indentifying drawn >>>Rook + f + h pawns vs. Rook arrangements. In the Crafty-Hiarcs game from the >>>last round of the tournament, it was kibitzing a draw score for quite some time. >>> >>>Could it be possible to encode such a large subset of knowledge into a faultess >>>"tablebase equivalent"? Or was it making the correct prediction for an incorrect >>>reason? >> >> >>Fritz was wrong. It kibitzed 0.0 for 50 moves. But if you remove rooks, white >>wins instantly due to distant majority/passer. Fritz 7 did not have a clue >>about that... > >Thanks, I came in around move 45 or so, I did not see the earlier announcements. > >Given that, I am wondering to what extent some of the R+h+f vs. R knowledge can >be encoded in a way similar to (Heinz 2003) from Advances in Computer Games 10. It is not hard. I have some code that seems to work, although it is not in the current version. It fits right in with the current KRP vs KR evaluation code that is present. It probably needs a bit more work, just like the recent changes to the KR[BN] vs KR stuff that had an exception I had missed. R/B pawns is not that easy to draw, so you have to catch anything that breaks it. I wrote some test code to run thru a bunch of KR[BN] vs KR positions and summed up wins and draws, to see where the problems are. It is not very easy to actually code things up, although king on the edge is pretty good. But it is not perfect, as a game we played while working on the book (against Hiarcs) showed. We were winning, but we went into a KRB vs KRPP (we had KRB) and thought we were winning because Hiarcs had the king on the h-file with our rook on the g-file. But we could not ever win that game... The exceptions are a pain. :) > >Has anyone attempted something similar to Heinz's work for the class of endgame >in which Crafty was in against Hiarcs? > >I agree Black was pressed to demonstrate the draw, especially since Crafty had >such a tremendous time advantage. we have krppkr already done. However, I didn't have any 6's on the quad opteron so that was a moot point. It would be interesting to take crafty on my dual and go back over the last 30 moves of that game to see if it would play differently with the tables available.
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