Author: Dann Corbit
Date: 13:22:46 03/06/06
Go up one level in this thread
On March 04, 2006 at 22:46:47, allan johnson wrote: >On March 04, 2006 at 16:48:33, Dann Corbit wrote: > >>On March 04, 2006 at 16:30:09, Charles Roberson wrote: >> >>> >>> >>> Telepath drew a won endgame in a blitz match this week. The position is: >>> 8/8/8/5BB1/8/3p1kpp/7P/7K w - - 0 76 >>> >>> It only searched 6 ply and played Bxh3. >>> At 10 ply it played Bxd3. >>> >>> Seems to me the better move is Bxd3 or h2xg3. >>> I've tried upping the outside passer value by 4x and adjusting >>> the code to call the d3 pawn an outside passer. Now, it makes >>> Bxd3 at 9 ply and h2xg3 at 10 ply then Bxd3 at 11 ply. >>> >>> Seems I should be able to adjust it to see this earlier or would >>> that be overtuning? >> >>Rybka likes Kg1 (which wins, but is a very puzzling choice because hxg3 >>obviously wins very easily.) Considering Rybka's long struggle to get off of >>the drawing Bxd3 I would not be too worried about it if my program struggled >>with it a while also. However, a 6 ply depth is a great concern if your program >>has more than one second of think time. Why so shallow? Severe time pressure? >> >>Analysis from e:\ttt.epd >>3/4/2006 1:34:36 PM Level: 999 Seconds >>Analyzing engine: Rybka v1.01 Preview 2.w32 >> >>1) 0 76 >> Avoid move: >> Best move (Rybka v1.01 Preview 2.w32): Kh1-g1 > > >Dann I'm puzzled.Your Rbyka programme does not consider hxg3 [21#] in 00.08.56 >whereas Mike Hurd version announces mate in 21 in 4 seconds.Is this because of >computer hardware or tablebases or is it something else I'm missing? >Al Not sure. hxg3 seems a real no-brainer to me (as a human it is what I would play and I don't think you even have to think to hard about it because it is obvious that it wins -- the other two bishop pawn-capture moves are much more complicated in my opinion, but I both of them win also) In any case, I think that Rybka is supposed to use EGTB now, and since a UCI engine, it should have the paths published to it. So I don't understand why Rybka makes such a strange choice. The other engines I tried since then do not make that same choice and most of them make hxg3 right away.
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