Author: Will Singleton
Date: 19:05:04 05/04/99
Go up one level in this thread
On May 04, 1999 at 20:41:48, James Robertson wrote: >On May 04, 1999 at 18:32:29, Will Singleton wrote: > >> >>On May 04, 1999 at 15:28:19, James Robertson wrote: >> >>>On May 04, 1999 at 15:03:08, Will Singleton wrote: >>> >>>> >>>>On May 04, 1999 at 13:07:42, KarinsDad wrote: >>>> >>>>>On May 04, 1999 at 12:40:05, Andrew Williams wrote: >>>>> >>>>>>On May 04, 1999 at 11:26:29, KarinsDad wrote: >>>>>> >>>>>>>I was wondering how deeply most programs extended the search at a given ply for >>>>>>>check. >>>>>>> >>>>>>>I implemented singular extensions, check extensions, and capture extensions into >>>>>>>my code last night, but ran into the problem of check extensions potentially >>>>>>>expanding the extensions into near infinity. >>>>>>> >>>>>>>How many checks do most programs consider is enough when extending? >>>>>>> >>>>>>>Thanks, >>>>>>> >>>>>>>KarinsDad :) >>>>>> >>>>>>My program simply says "if the iterative deepener started this search >>>>>>with depth=D, don't extend beyond 2*D". This is a naive approach, and >>>>>>I'd also be interested in hearing what anyone else does. >>>>> >>>> >>>>Sometimes the simple approach is the best. In mine (which I'm sure is not the >>>>best), I simply limit total extensions to 6 beyond depth. But I also consider >>>>some checks in the qsearch. >>>> >>>> >>>>>Yes, this sounds naive since I especially do not want to check 14 ply down when >>>>>I am currently searching Ply 14. I was thinking more along the lines of 8 ply >>>>>(if you do not get an advantage within 4 moves, then maybe it isn't worth >>>>>checking), but I am not sure. >>>>>> >>>>>>> >>>>>>>PS. Will, we realized that our nps is way off. We were compiling the code in >>>>>>>debug mode as opposed to optimized mode. So, our 100 knps went up to 209 knps. >>>>>>>Duh! >>>>>> >>>>>>209knps!! What position? >>>>> >>>>>This is on a P3 400 Mhz with super simple material evaluation code (for a lot of >>>>>positions, the program is still real stupid). It will drop in half at least once >>>>>I really implement the evaluation. >>>>> >>>>>> >>>>>>Andrew >>>> >>>>The most nps I get is around 90k, in the endgame. Avg around 60k on a mac 300. >>>>Even with a material only eval, I don't approach your numbers. You must be >>>>doing something right! >>>> >>>>btw, it's possible that you'll see reduced node counts due to increased cutoffs >>>>when you add some positional stuff. >>>> >>>>Will >>> >>>On my P233 I get about 120k NPS in most middlegame positions. In the endgame, I >>>get 200-270k NPS. With material only, I got greater than 300k. >>> >>>James >> >>What search method do you use? And is it bitboard-based? > >Standard Alpha-Beta. And yes, I use bitboards, and a ton of assembly in my basic >movegenerating, etc. > >James Assembly and bitboards, huh? Bitboards I understand, but assembly? I always found it tough to modify, pretty intense. This was 80x86 and 68000 stuff. Compilers are pretty good these days, how much do you think you gain? Will
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