Author: Gerrit Reubold
Date: 16:20:15 06/18/00
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On June 18, 2000 at 15:12:43, Gian-Carlo Pascutto wrote: >On June 18, 2000 at 14:55:43, pete wrote: > >>Looks pretty impressive to me ; unfortunately you will have to wait for Gerrit >>Reubold to exlain the interesting part of your question :-) > >I'm interested for sure. The results you posted beat everything else >hands down. > >The maximum effective branching factor (measured by time) is as low as >5 AND it spots the mate quickly. > >-- >GCP Hi all, unfortunately I am unable to reproduce Pete's results with the current version of Bringer. I don't know which version he used (I sent him many betas), his hashable settings etc. These are my results (PII-300 14 MB Hash): 0:00:00.2 ( 4/12) 2691 -1.19 c1-b1 a6-a4 d3-e4 g8-f8 0:00:00.9 ( 6/16) 55650 -1.26 c1-b1 b7-b5 d3-e4 g8-f8 c4xb5 a6xb5 0:00:02.0 ( 7/21) 138751 -1.39 c1-b1 b7-b5 c4xb5 b8xb5 e3-e4 a8-b8 0:00:03.7 ( 7/22) 267661 -0.88 h3xh5 0:00:05.7 ( 8/26) 381065 -1.03 h3xh5 g6xh5 h1xh5 g8-f8 h5xh7 f8-e8 d3-f5 f7-f6 0:00:08.6 ( 9/26) 663786 -0.63 h3xh5 0:00:11.6 ( 9/29) 960843 -0.23 h3xh5 0:00:18.1 ( 9/29) 1572723 0.38 h3xh5 g6xh5 h1xh5 g8-f8 d3xh7 f8-e8 h7-f5 e8-d8 h5-h8 d8-c7 h8xb8 a8xb8 f5xf7 0:00:24.8 (10/36) 2335509 0.78 h3xh5 0:00:31.3 (10/36) 2942408 1.18 h3xh5 0:01:10.4 (10/36) 7566834 12.80 h3xh5 g8-f8 0:01:21.5 (11/36) 8816266 13.20 h3xh5 0:01:29.9 (11/36) 9654231 13.60 h3xh5 0:01:42.0 (11/36) 11323902 Matt in 11 h3xh5 a6xa2 h5xh7 e7-e5 Bringer is lucky with the extensions. Just the right extension and not too many unnecessary extensions. I guess this is more luck than good tuning, the next position can easily show a bad performance of Bringer. Here are some statistics which were collected during the search, which looked at 11.414.517 nodes: Fail high 1st move: 80 % <<< move ordering not so good here, Bob Hyatt's percentage of strongly ordered trees is 90% Moves per fail high: 1.86 Extensions Check: 252678 <<< the well know check extension Recapture: 13542 <<< recapture extension, also standard PawnPush: 8019 <<< pushing passers to 6th or 7th rank SingleMove: 46035 <<< extend when player has only one move Threat: 5180 <<< extend when the opponent has a severe threat Razor: 8189 <<< a negative extension, some pruning, razoring Perpetual: 24230 <<< extension to detect perpetual checks, hurts the performance in this position Endgame: 9963 <<< these extensions are probably very unnecessary in this position Null Search Null Searches: 764285 Success rate: 79 % Node rate: 43 % You can download Bringer at www.reubold.onlinehome.de Bringer displays these search statistics, you can do experiments and get a feeling for the positions in which the extensions do / do not work. Greetings, Gerrit
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