Author: Uri Blass
Date: 22:20:48 11/03/05
Go up one level in this thread
On November 03, 2005 at 10:49:01, Joachim Rang wrote: >On November 03, 2005 at 10:39:17, Uri Blass wrote: > >>On November 03, 2005 at 09:21:17, Uri Blass wrote: >> >>>On November 03, 2005 at 08:40:02, Ignacio Santos Crespo wrote: >>> >>>>Hi Uri, >>>> >>>>Thank you for your answer. The following position is interesting: Fruit crash >>>>and Movei crash after depth 16. >>>> >>>>Mate in 69 >>>> >>>>[D]1K1n2q1/1p4pR/1prPPpPn/1RB1p1rP/8/1B2p3/2p2b2/1k2N3 w - - 0 1 >>>> >>>>Regards, >>>>Ignacio. >>> >>> >>>Thanks for posting it. >>> >>>I could verify that the public version crash in console mode at depth 16 >>>when latest private version even crash at depth 14. >>> >>>The question is also what is the reason that fruit crashed. >>>If it crashed because the interface cannot get long pv then it may be a bug in >>>the interface but if it crashed because of another reason then it is a bug in >>>the engine. >>> >>>Uri >> >>More details >> >>The version that was compiled by Dan Crobit crash at depth 14 >>slower version that was compiled by me does not crash and can get even depth >>17(maybe the reason is that I added some printf that print the maximal ply every >>time that it get it and for some reason the bug with printf does not lead to >>crash but only to high depth that is not logical(I get branching factor that is >>close to 1.2 or 1.3 at depth 14-17) >> >>the maximal selective depth of movei is 100 so it cannot see mate in 69 >> >>At depth 13 the maximal selective depth that movei search in this position is 97 >>At depth 14 it get selective depth of 100 and it seems that the version that Dan >>Corbit compiled crash near the time that it gets selective depth of 100 plies. >> >>I suspect that the problem may be that my arrays are too short at some point >>I tried to reduce the maximal search depth to 99 and it did not help. >> >>I tried again to reduce the maximal search depth to 97 and it did not crash but >>it also does not get depth 17 fast like the previous version and at the time of >>posting it only started depth 16 that is clearly logical because I do not expect >>branching factor of 1.2 and branching factor that is slightly more than 2 is >>clearly more logical. >> >> >>Uri > > >it has to do with the compiler. Fruit compiled by Bryan Hofmann (official >version ) crashes while other dev-compile from me does not. Probably some kind >of optimization which can cause a crash in rare circumstances. > >Joachim In the case of movei the bug is clearly arrays that are too short. I am testing latest movei and it does not crash but of course it has no chance to see the mate and not only because 100 plies is the maximal depth that it can look forward but because checks and single replies do not interest it in case that the advantage is for the attacking side and after seeing advantage it is happy enough not to extend. It finish depth 16 and gets a pv of 86 plies and score of 5.55 pawns for white without crashing. pv is not changed at depth 17 and I am not going to continue to depth 18. Here is the pv at depth 17 17 555 103453 528725676 b3c4 b1c1 c5a3 c1d2 a3b4 d2c1 e1d3 c1d1 d3f2 e3f2 b5d5 d1c1 b4a3 c1b1 d5b5 b1a1 a3b2 a1b1 b2d4 b1c1 d4e3 c1d1 b5d5 d1e1 e3d2 e1d1 d2g5 d1e1 g5d2 e1d1 d2b4 d1c1 b4a3 c1b1 d5b5 b1a1 a3b2 a1b1 b2e5 b1c1 e5f4 c1d1 b5d5 d1e1 f4d2 e1d1 d2b4 d1c1 b4a3 c1b1 d5b5 b1a1 a3b2 a1b1 b2f6 b1c1 f6g5 c1d1 b5d5 d1e1 g5d2 e1d1 d2h6 d1e1 h6d2 e1d1 d2f4 d1e1 d5e5 e1d1 c4e2 d1e1 e2g4 e1f1 g4h3 f1g1 e5g5 g1h1 h3g2 h1g1 g2c6 g1f1 c6b5 f1e1 g5e5 e1d1 Uri Uri
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