Author: Paul Richards
Date: 15:21:54 03/28/99
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On March 28, 1999 at 11:05:09, Dave Gomboc wrote: >Crafty is capable of using 16 processors, maybe more, I don't know exactly. >Fritz would probably love to have a gigabyte of ram. Whatever. If you are >trying to compare program quality, you can't cripple one of them, then say >"look, the other one is way better". Well, actually you can, but it sounds >silly. You don't have to cripple anything to make a comparison. Here is an easy example: 1.e4 e5 2. Nf3 Nc6 3. Bb5, the start of the Ruy Lopez. Using Crafty 16.5 engine in Fritz interface, I set this position and started Infinite Analysis. In the 10-12 ply range Crafty recommends the positionally atrocious 3...Bd6? as black's best. Sure it develops the bishop and defends the pawn, but the pawn does not need defense. White exchanging on c6 fails to Qd4, so white will never take the pawn. So all Bd6 accomplishes is to block the d pawn and light squared bishop. This is obvious even to non-masters, and a Kasparov seeing something like this would be enough to conclude how Crafty plays. I let it continue to think to 15 ply, and when I came back after a number of hours it had chosen the sensible 3...a6. But 12 plies is already a significant depth, and Bd6 should have been rejected before this. For Fritz Bd6 is never a serious contender even at shallow search depths. So this is a difference in how positions are evaluated and has nothing to do with hardware, optimal compilation or what have you. I reran this test several times, and on one occasion Crafty did like 3...a6 up until 12 ply, where it switched back to Bd6. I don't know why it isn't consistent, but I don't have a standalone version of Crafty to test. I just tested 16.6 engine on the same position, and see a clear improvement in the recommendations. Its choices at 12 ply are a6, f5, Bc5, and only then Bd6. The point is that this is the sort of thing that needs to be tuned, not whether Crafty can play on 100 processors. That part is already superior to commercial programs, it is the weaknesses that need attention.
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