Author: Robert Hyatt
Date: 19:53:45 07/05/04
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Here is what actually happened in round 1. 1. At move 60 crafty displayed a message "Game is a draw by repetition." This is _not_ the way crafty claims a draw, for those that remember the discussion after the last WCCC where _everybody_ was claiming draws contrary to the way the FIDE rule book stipulates. So far are I know, crafty was the _first_ program to correctly claim a draw whether it be by repetition, 50 moves, or just plain offering a draw in the right circumstance. The above message was left in ponder.c (Ponder) when I was debugging this stuff over a year ago. It was left in and produced a "red herring" as several thought the "problem" was with repetitions. 2. The _real_ problem was an artifact caused by reaching the first time control, with a value unset. Namely the number of moves in the secondary time control, which should be > 0. Unfortunately, the instructions I gave Peter about setting the time control contained two options. One way would have worked perfectly, while the other set the secondary time control moves to zero. Peter chose the latter (not knowing there was a bug) because it was simpler. At move 60, it went to the secondary time control, computed the target time by dividing time left by the secondary time control move limit, and promptly got a divide by zero crash. Since I had never played setting things up the way Peter did, this had never been seen. However, it was a definite bug, and round 2 would have crashed had it made it to move 60 as well. This has now been fixed so there will be no further occurrences of this particular problem. The cause was a simple bug, based on how Peter was trying to "hide" time to compensate for his move entry and so forth. There was no "error" on his part, it was just one of those untested combinations of set-up commands that caused the problem...
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