Author: Bernhard Bauer
Date: 06:52:45 03/01/00
Go up one level in this thread
On March 01, 2000 at 09:15:18, James T. Walker wrote: >On March 01, 2000 at 08:48:41, Bernhard Bauer wrote: > >>On March 01, 2000 at 08:13:11, Dave Gomboc wrote: >> >>>On March 01, 2000 at 03:42:23, Bernhard Bauer wrote: >>> >>>>On March 01, 2000 at 02:58:49, Dann Corbit wrote: >>>> >>>>>On March 01, 2000 at 01:37:17, Janos Keinrath wrote: >>>>> >>>>>>Hi! >>>>>> >>>>>>Yesterday I saw an intresting endgame position on ICC. >>>>>> >>>>>>[D]8/8/6k1/3p4/3P4/2P2PKp/pB4b1/8 b - - >>>>>> >>>>>>This is the final position of a blitz game played by Amateur >>>>>>with black. The game ended with rep. draw, but I feel black somehow >>>>>>can win. Could you check the position? What is the winning plan? >>>>> >>>>>Crafty likes Kf5 from the get-go, but the evaluation does not climb over one >>>>>pawn until ply 19. I'd be surprised if programs see a win at normal game-type >>>>>time controls (other than 'postal' games). >>>> >>>>This position is a simple win for black. >>>>For example: >>>>1... Kf5 >>>>2.Ba1 Bf1 >>>>3.Bb2 Be2 >>>>4.Ba1 h2 >>>>5.Kxh2 Kf4 >>>>5.Kg2 Bxf3 >>>>6.Kf2 Ke4 >>>>7.Ke1 Kd3 >>>>and black wins the white bishop and the game. >>>>White may defend in a different way, but without any hope. >>>>A human will win this position easyly. >>>> >>>>Crafty does very poor on this kind of positions. So it's output here >>>>is not very usefull. >>>>Look at H. Exner's pawn endgame test, pos12 >>>>8/6Bp/6p1/2k1p3/4PPP1/1pb4P/8/2K5 b - - bm b2; >>>>or on the famous position from Topalov-Shirov >>>>8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - 0 47 >>>> >>>>Kind regards >>>>Bernhard >>> >>>Crafty did just fine on this position, at least on my computer (2xPII-266). >>> >>>Dave >> >>Crafty may behave diferent due to hash settings, extension settings and >>unknown things especially an multi proc systems. >>Without changing the extensions I get >> >> 17-> 5.20 0.61 1. ... Kg5 2. Ba1 Bf1 3. Bb2 Kf5 4. >> Ba1 Kf6 5. Bb2 Bg2 6. Ba1 Ke6 7. Bb2 >> Kf5 8. Kf2 Bh1 9. Ba1 Bg2 >> 18 10.71 0.60 1. ... Kg5 2. Ba1 Bf1 3. Bb2 Kf5 4. >> Ba1 Kf6 5. Bb2 Bg2 6. Ba1 Ke6 7. Bb2 >> Ke7 8. Ba1 Kd6 9. Bb2 Bf1 10. Kh2 >> 18 21.61 ++ 1. ... Kf5!! >> time=30:00 cpu=200% mat=0 n=1199751062 fh=1% nps=666506 >> ext-> checks=234624777 recaps=1254995 pawns=1005159 1rep=28133248 >>thrt:6425 >> predicted=0 nodes=1199751062 evals=8539222 >> endgame tablebase-> probes done=0 successful=0 >> SMP-> split=1340 stop=113 data=9/64 cpu=60:00 elap=30:00 >> >>I wouldn't call this "doing just fine" >> >>Kind regards >>Bernhard > >Hello Bernhard, >I guess I miss your point. It takes Crafty almost 22 seconds to play Kf5 which >is the best first move in your line. So sure Crafty would not win this at blitz >but at tournament time it would probably win this position from the black side. >I doubt if most humans would win this position at blitz either. >Jim Walker My point is not that Crafty didn't find the first move, it did. And not that Crafty took too long to find it, it didn't. My point is that Crafty gives no usefull output, even in a 30 min run. This is bad for analysis purposes, not necessarily for playing games. IMHO Crafty blows up, you see 234 million check extensions. Kind regards Bernhard
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