Author: Paul
Date: 10:46:43 10/28/01
Go up one level in this thread
On October 28, 2001 at 12:26:12, leonid wrote: >>Actually, my selective (and I expect that this is the same for every other >>program) search only promissing moves. Promissing moves are those moves that >>give quick response in most of cases. Not necesserily the shortest response. >>Checking moves are the most promissing. Moves that affect vital king's lines are >>the next, and so like. Between many variations of "promissing moves" I left only >>checking because they provide high simplicity of code and no need for big >>look-up tables. After having the chance to write my 64 bits program (if it will >>ever happened) I, probably, will look once again into my code to see if old >>ideas still have sense. With each big speeding old trick for "speed against >>depth" become useless. > >It came to my mind to illustrate how effective is sometime selective, even if it >goes much longer way that brute force. In this position my selective find mate >only at 12 moves. It is mate in 9. > >Actually, it is nothing more but veriation of previous mate. > >[D]bBQQ1nrq/b2NNq1k/K6n/PQqq1qPB/3Q1Q2/3r1qR1/3q2q1/3RQQq1 w - - > >Selective do the work in 12 moves, in 2 secondes. Brute force in 9, in 1 min 30 >sec. Celeron 600. > >Cheers, >Leonid. Yes, Pretz using my "old Leonid settings" finds a mate in 9 in 19 seconds here (on a P3/933): 00:19 WM9 09 Nxf8+ Qxf8 Qxh8+ Kxh8 Qee5+ Kh7 Qcxf5+ Qxf5 Qfxf5+ Qxf5 Qfxf5+ Nxf5 Qxf5+ Kh8 Qf6+ Kh7 Qh6# I'm just now experimenting with some new extensions, and it's a bit quicker here with one of those, 12 seconds. But it's very tricky to find the right combination of extensions that work just right in all positions. I still do not ignore any moves, apart from what alpha-beta skips. I will try later to be more selective about chosing moves, I think pruning can save more time. Thanks for your positions Leonid, I'm having a lot of fun again these last few days programming Pretz ... Groetjes, Paul
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.