Author: Dave Gomboc
Date: 07:28:56 03/01/00
Go up one level in this thread
On March 01, 2000 at 09:52:45, Bernhard Bauer wrote: >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 Well, my computer resolved the fail high in twenty seconds or so. Odd. Dave
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