Author: Slater Wold
Date: 22:24:25 08/29/01
Go up one level in this thread
On August 30, 2001 at 00:54:03, Jeremiah Penery wrote: >On August 29, 2001 at 23:19:43, Slater Wold wrote: > >>On August 29, 2001 at 13:14:41, José Antônio Fabiano Mendes wrote: >> >>> Cray Blitz vs Belle [1981 North American Computer Chess Championship] >>> The (in)famous position Dr. Hyatt referred to the other day: >>> [D]5r1k/6p1/1n2Q2p/4p3/8/7P/PP4PK/R1B1q3 w >>> And here Cray Blitz played 28.Qxb6 >>> Source: http://wondersmith.com/rants/howfar.htm >> >>I understand that CB took only 10 seconds to play, and was limited to 1K nps. >>However, I wanted to post this, to show only 1 thing: >> >>position: >> >> 8.01 0:00 -0.25 1.Bf4 Qxa1 2.Bxe5 Kh7 3.Qxb6 Qxa2 4.b4 Rf7 5.Qe3 Qb1 >>(268.921) 312.3 >> 9.01 0:02 -0.18 1.Bf4 Qxa1 2.Bxe5 Kh7 3.Qxb6 Qxa2 4.b4 Rf7 5.b5 Qd5 6.Qb8 >>(903.942) 321.2 >> 9.03 0:04 -0.17++ 1.Bxh6 Qxa1 2.Qg6 Rg8 3.Bf4 Rb8 4.Bxe5 Rb7 5.Qc6 Kh7 >>6.Qxb7 Qg1+ 7.Kxg1 (1.356.976) 321.8 >> 9.03 0:04 0.00 1.Bxh6 Qxa1 2.Qg6 gxh6 3.Qxh6+ Kg8 4.Qg6+ Kh8 5.Qh6+ Kg8 >>(1.533.066) 325.0 >> 10.01 0:07 0.00 1.Bxh6 Qxa1 2.Qg6 gxh6 3.Qxh6+ Kg8 4.Qg6+ Kh8 5.Qh6+ Kg8 >>(2.517.038) 332.0 >> 11.01 0:27 +0.01 1.Bxh6 Qxa1 2.Qe7 Rg8 3.Be3 Rc8 4.Bxb6 Qxb2 5.Bc7 Qxa2 >>6.Bxe5 Qg8 7.Qh4+ Qh7 8.Qg4 (9.074.087) 331.3 >> 12.01 1:00 +0.26++ 1.Bxh6 Qxa1 2.Qe7 Rg8 3.Be3 Rc8 4.Bxb6 Qxb2 5.Bc7 Qxa2 >>6.Bxe5 Qxg2+ 7.Kxg2 Re8 8.Qxe8+ (19.746.518) 327.1 >> 12.01 1:30 +0.68 1.Bxh6 Qxa1 2.Qe7 Rg8 3.Be3 Qb1 4.Bxb6 Qg6 5.Be3 Re8 6.Qd7 >>Kg8 7.a4 Qf7 8.Qc6 Kh8 (29.906.848) 331.8 >>best move: Bc1xh6 time: 3:04.325 min n/s: 321.286 CPU 98.6% nodes: 59.221.207 >> >>Deep Shredder here takes a little over 3 minutes, and plays Bxh6. I choose 3 >>minutes, because it is a good time for an average tournament move. In 3 minutes >>it hits roughly 60M nodes, at a rate of 321K nps. >> >>If CB had search 60M nodes, it would have taken 987 hours. However, as you can >>see in Deep Shredder's eval, it _NEVER_ looks at Qxb6. So the knowledge is in >>Deep Shredder. > >The output you pasted starts at 8 ply. Does Shredder look at Qxb6 from ply 1-7? > I think it probably does at some point. I am not sure how much you pay attention to the eval of _most_ chess programs, but most skip the first few plies. If you look at the average nps I was getting (321,286 nps) and then look at the total nodes searched at the end of the first shown ply (268,921) you'll see that it started on ply 8. Deep Shredder is packed with knowledge, and is a "selective search" engine. Therefore, it's safe to say it "skipped" over the first 8 ply, and started to actually "search" at ply 8. Perhaps some of the more knowledgable programmers can give you more details on this. But just looking at the nodes, it makes sense to me. Slate
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