Author: Bruce Moreland
Date: 08:48:09 05/21/01
Go up one level in this thread
On May 21, 2001 at 10:18:16, Robert Hyatt wrote: >On May 21, 2001 at 06:52:52, Uri Blass wrote: > >>This position could happen in kasparov-Deeper blue but kasparov did not play >>40.gxh5 >> >>Based on Deeper blue logfiles we know that Deeper blue evaluated the position >>as 0.5 pawn advantage for white at depth 9(6)=15 >> >>Crafty's evaluation at depth 15 is 2.93 pawns for white so we can see that the >>difference in evaluation is 2.43 pawns. >> >>Part of the difference can be explained by different evaluation but most of the >>difference is clearly because of the fact that Crafty can see more than Deeper >>blue. > >You should be able to see crafty's PV, which would clearly explain whether >the 2.9 is position or material. Unfortunately, you can not see DB's PV >so there +.5 is totally unknown. IE it could be just a bit better positionally, >it could be material down and a really big positional plus. Who knows? and >who can tell? You give a supported pawn on the 7th a big bonus, and that's what white has here. So I'm betting it's a positional thing. bruce > > > >> >>Deeper blue found the line 40...Bxh5 41.Rh1 only at depth 10(6)=16 when Crafty >>could see it at depth 14 and the line was not changed at the next 2 plies. > >This is the same problem. My eval is tuned to more risky play, because of the >opposition I see on ICC all the time. In some types of positions I would >expect it to get a much better picture of the real score than DB. But in >others I would expect it to get a worse idea. And tactically, it would be >no competition with DB having a huge edge. > >If DB searches 16, and crafty searches to 16, I would prefer the non-null-move >16 any day. It is _clearyly_ more accurate. > > > > > >> >>Crafty can see the line 40...Bxh5 41.Rh1 Bf3 42.Rg1 Bh5 43.g7 Nf3 44.Rg3 c5 >>45.bxc5 Rc8 46.f6 Rxc5 at depth 15 and 16 when Deeper blue can see it only at >>depth 17,18(deeper blue can see a different line but the difference is only >>41...Kg5 42.Rg1 Kh6 that leads to the same position as 41..Bf3 42.Rg1 Bh5 and >>moves 43-46 are the same. >> >>It seems that Crafty is a very good program and it can outsearch deeper blue by >>2 plies. > > >That's a speculation that is based on too many what-ifs. IE what if you just >let each program search for 3 minutes? Which is better? I don't like to >compare search depth to search depth, as that is usually a totally wrong way >to compare programs. IE you might try hiarcs at the same depth and find that >it sees more or less. > >Plies between programs are not really interesting. > > > > >> >>I do not know the meaning of the plies of deeper blue but it seems to be not >>brute force search. >> >>I also doubt if deeper blue could search 200M nodes per second otherwise I >>cannot understand the reason that it is outsearched by other top programs again >>and again based on the pv's > >What "top program" sees more in 3-4 minutes than they do? IE what program >can solve all the nolot positions in reasonable time (maybe 1-2 exceptions >as I think they missed one or two). But who can do all but 2 in 3-4 minutes? >To say "top programs outsearch them" therefore seems strange. Unless you mean >"top programs outsearch them given _enough_ time". And that is always true and >meaningless at the same time. > > > > >> >>It is possible that the claims about 200M nodes per second were only a >>psychological war against kasparov > > >Not a chance... I have sat behind them and watched too many times... > > >> >>Here is the analysis of Crafty >> >>kasparov - Deeper blue >>[D]3rr3/8/2p3Pk/1p2nP1P/pP2p3/P1B1Nb1B/2P2K2/5R2 b - - 0 1 >> >>Analysis by Crafty 18.08: >> >>40...Kxh5 >> +- (1.42) Depth: 1/8 00:00:00 >>40...Kxh5 41.g7 Ng4+ 42.Bxg4+ Bxg4 >> +- (1.68) Depth: 2/8 00:00:00 >>40...Kg7 41.f6+ Kxf6 >> +- (1.53) Depth: 2/8 00:00:00 >>40...Kg7 41.f6+ Kxf6 42.Kg3 >> +- (1.53) Depth: 3/8 00:00:00 >>40...Kg7 41.Ng4 Bxg4 42.Bxg4 c5 >> +- (2.58) Depth: 4/10 00:00:00 >>40...Rd6 >> +- (2.18) Depth: 4/10 00:00:00 >>40...Rd6 41.Rg1 Bxh5 42.g7 Bf7 >> +- (2.03) Depth: 4/10 00:00:00 >>40...Kxh5 >> +- (1.63) Depth: 4/10 00:00:00 >>40...Bxh5 41.Bg2 Bf3 42.Bh3 >> ± (1.34) Depth: 4/10 00:00:00 >>40...Bxh5 41.Bg2 Nxg6 42.fxg6 Rf8+ 43.Ke1 Rxf1+ 44.Kxf1 Bxg6 >> ± (1.33) Depth: 5/16 00:00:00 >>40...Bxh5 41.Kg3 Kg5 42.Rf4 Bf3 43.Rh4 >> +- (1.62) Depth: 6/16 00:00:00 88kN >>40...Bxh5 41.Rg1 Kg7 42.Bg4 Kh6 43.Bxe5 Rxe5 44.Rh1 >> +- (1.76) Depth: 7/19 00:00:01 222kN >>40...Bxh5 41.Rg1 Nf3 42.Rh1 Kg5 43.g7 Rg8 44.f6 Kf4 >> +- (1.81) Depth: 8/20 00:00:01 480kN >>40...Bxh5 41.Rg1 Nf3 42.Rh1 Ne5 43.Bg2 Nxg6 44.fxg6 Kxg6 >> +- (1.78) Depth: 9/23 00:00:03 1223kN >>40...Kxh5 41.Rg1 Kh4 42.Bf1 Kh5 43.g7 Ng4+ 44.Nxg4 Bxg4 45.Rh1+ Kg5 46.f6 e3+ >>47.Kg3 >> +- (1.77) Depth: 9/23 00:00:04 1778kN >>40...Kxh5 41.Rg1 Kh4 42.Bg2 Bxg2 43.Rxg2 Kh5 44.g7 Nf7 45.Rg6 Nd6 46.Bd4 >> +- (2.01) Depth: 10/26 00:00:07 3318kN >>40...Bxh5 41.Kg3 Kg5 42.g7 Nf7 43.f6 Rg8 44.Rf4 Bf3 45.Be6 Kg6 >> +- (1.94) Depth: 10/26 00:00:14 6548kN >>40...Bxh5 41.Kg3 Kg5 42.g7 Nf7 43.f6 Rg8 44.Be6 Bg6 45.Rh1 Rd6 46.Bg4 >> +- (2.16) Depth: 11/27 00:00:24 11929kN >>40...Kxh5 41.Rg1 Kh4 42.Bg2 Bxg2 43.Rxg2 Kh5 44.g7 Nf7 45.Bf6 Rd2+ 46.Kf1 Rxg2 >>47.Kxg2 >> +- (2.14) Depth: 11/27 00:00:33 16243kN >>40...Kxh5 41.Rg1 Kh6 42.g7 Nf7 43.Rg6+ Kh7 44.Rxc6 Rc8 45.Rxc8 Rxc8 46.Bd4 Rd8 >>47.Bc3 Kg8 >> +- (2.53) Depth: 12/29 00:01:24 41952kN >>40...Bxh5 41.Kg3 Kg5 42.g7 Nf3 >> +- (2.45) Depth: 12/29 00:01:48 54476kN >>40...Bxh5 41.Kg3 Kg5 42.g7 Nf7 43.Rf4 Nd6 44.f6 Bg6 45.Rg4+ Kh5 46.Kf4 Rg8 >>47.Rg5+ Kh4 48.Be6 >> +- (2.71) Depth: 13/32 00:02:59 89583kN >>40...Bxh5 41.Rh1 Kg5 42.Rg1+ Kf6 43.Bg2 Bf3 44.Bxf3 exf3 45.g7 Kf7 46.g8Q+ Rxg8 >>47.Rxg8 Rxg8 48.Bxe5 Re8 49.Ng4 >> +- (2.61) Depth: 14/34 00:08:56 267478kN >>40...Bxh5 41.Rh1 Bf3 42.Rg1 Bh5 43.g7 Nf3 44.Rg3 c5 45.bxc5 Rc8 46.f6 Rxc5 >>47.Bb4 Rg5 48.Rxg5 Kxg5 >> +- (2.93) Depth: 15/39 00:23:36 722662kN >>40...Bxh5 41.Rh1 Bf3 42.Rg1 Bh5 43.g7 Nf3 44.Rg3 c5 45.bxc5 Rc8 46.f6 Rxc5 >>47.Bb4 Rg5 48.Rxg5 Kxg5 49.Be7 >> +- (3.06) Depth: 16/40 00:43:40 1309529kN >> >>(Blass, Tel-Aviv 21.05.2001) > > >That shows that Crafty can get to depth=16 after searching a billion nodes. >With Null-Move (R=3) that equates to a brute-force of 13 plies. I'm not sure >how to reach any comclusion from that. > >There are _always_ positions that Crafty will evaluate better than _anybody_. >There are always positions where it will evaluate worse. Ditto for tactics. >Unfortunately, one position doesn't win a game, although one can lose it.
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