Author: James Robertson
Date: 17:41:48 05/04/99
Go up one level in this thread
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 > >Will
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