Author: Tony Werten
Date: 00:03:19 11/05/03
Go up one level in this thread
On November 04, 2003 at 13:58:29, Christophe Theron wrote: >On November 04, 2003 at 02:43:34, Tony Werten wrote: > >>On November 03, 2003 at 13:22:42, Christophe Theron wrote: >> >>>On November 03, 2003 at 10:04:32, Will Singleton wrote: >>> >>>>On November 03, 2003 at 02:35:09, Gerd Isenberg wrote: >>>> >>>>>On November 03, 2003 at 02:33:02, Gerd Isenberg wrote: >>>>> >>>>>>On November 02, 2003 at 17:12:38, Will Singleton wrote: >>>>>> >>>>>>>On November 02, 2003 at 16:52:49, Gerd Isenberg wrote: >>>>>>> >>>>>>>><snip> >>>>>>>>>In the same vein, the following position has always been a nightmare for Tiger: >>>>>>>>> >>>>>>>>>[D]8/1KP5/3q2k1/8/6p1/8/8/8 b - - >>>>>>>>> >>>>>>>>>This position comes from a real game between the Modular Game System Sargon 2.5 >>>>>>>>>and Mike III, played in September 1980 during the Personal Computer World Fair. >>>>>>>>>Mike III continued the game with a long series of checks leading to a draw. >>>>>>>>> >>>>>>>>>Chess Tiger is not smarter than Mike III here. It is something that I had fixed >>>>>>>>>in the 16 bits version, to the expense of some added complexity in the passed >>>>>>>>>pawns evaluation code. I have not transfered this code to the 32 bits version >>>>>>>>>because it was not general enough (add another black pawn and the code did not >>>>>>>>>work). >>>>>>>>> >>>>>>>>>I am interested in results of other (amateur and commercial) programs. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Christophe >>>>>>>> >>>>>>>>Hi Christophe, >>>>>>>> >>>>>>>>IsiChess on AMD XP2.6+ first shuffles around with Qb4+, Qxc7 and Qd7. >>>>>>>>After 5 seconds at depth 13 Qxc7 came up. Mate in 14 resp. 12 after one minute >>>>>>>>and 1:10. I guess a matter of won KPK eval. >>>>>>>> >>>>>>>>Cheers, >>>>>>>>Gerd >>>>>>> >>>>>>>Sure, but I'm not sure CT was referring to finding the mate as the problem. CT >>>>>>>seems to have some problem understanding that KQK is better than KQKP, that's >>>>>>>all I can figure. >>>>>>> >>>>>>>Will >>>>>> >>>>>you mean won KPK against KQPKP? I use interior node recognizers and assign >>>>>shlightly more than queen advantage in won KPK. Additionaly there is a >>>>>heuristic, that reduces score a bit (e.g. abs(delta material) / X) if a lot of >>>>>checks occur with "no progress". >>>>> ^^^^ >>>>>Gerd >>>> >>>>I do that too, but it's constrained to several consecutive checks that don't >>>>reset the fifty-move counter. Seems to help in some positions, but I'm not sure >>>>how generally effective it is. >>>> >>>>Will >>> >>> >>> >>>That's exactly what I have tried, with different values for X and the number of >>>consecutive checks needed to trigger it. >>> >>>It has always weakened my program. Not by much, but I expected a minor gain, not >>>a minor loss! >> >>Make sure your trigger is counted from the back, not the front. ( I don't want >>to make it too easy :) >> >>Tony > > > >I really don't understand what you mean... Whatever adjustments you do after no progress, it is only important if the last fe 5 moves made no progress (or gave checks). If the first 5 moves did this and then there is a no-check or capture you should do nothing. If you trigger from the front (ie root) you'll seriously weaken the engine because sometimes it is nescessairy to shuffle some pieces around before doing something, but you will be giving a penalty for that. Tony > > > > Christophe
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