Author: Michel Langeveld
Date: 12:16:28 11/20/04
Go up one level in this thread
On November 20, 2004 at 13:24:26, Pallav Nawani wrote: >On November 20, 2004 at 08:51:46, Michel Langeveld wrote: > >>I decided to investigate something: >> >>TSCPGothic NORMAL >>================= >>This program generates moves, and after a move is played, it checks if the own >>king is brought into check. If this was the case, then it undoes the move >>without searching futher, and continues with another move. >> >>TSCPGothic KINGCAP >>================== >>This program generates moves, plays them all despite legalness, and let the king >>get captured (Crafty makes this too). >> >>I hoped for a faster program with KINGCAP. >>I found out that this was not true (Note *2) >> > >The way it is supposed to be done: > >1. Do it only in qsearch. No point in doing it in main search, it is already >doing some heavy lifting, checking move legality there is not such a big strain. >Also, if you have a crafty like incremental move generator, you may try many >moves before finding the king capture. >Net result: you loose time. > >2. After you recurse to the next ply (in qsearch), check the moves you have >generated. If one of them is a king capture, return beta or Mate score >immediately. Again, this won't work if you have an incremental move generator. >Crafty generates all the moves in one shot while in qsearch. > >So, No eval is needed, and you don't check the move is illegal or not & thus you >save time. The assumption, of course, being that most of the moves are legal and >by not checking move legality immediately we may save some time. > >Also, if your qsearch is heavy, that is, it has SEE + Checks in qsearch + etc >etc, then the benefit of KingCap approach will be low. > >Best regards, >Pallav Thanks a lot! I did it this way. The positions with KINGCAP go now few % faster as without. So I keep it: ============================================================================ KINGCAP: 11* 7864 28631090 266 h2g1q f1g1 h7h6 d1d3 i8j6 h3f4 g8i6 j8h6 e8f6 g1f1f6h6 c3e4 NORMAL; 11* 7940 28599916 266 h2g1q f1g1 h7h6 d1d3 i8j6 h3f4 g8i6 j8h6 e8f6 g1f1f6h6 c3e4 ============================================================================ ============================================================================ KINGCAP: 11* 4192 13613673 11 b1c3 b8c6 d2d4 i8h6 d4d5 c6e5 d1d4 d7d6 c1d2 h6f5 d4e4 NORMAL: 11* 4251 13607954 11 b1c3 b8c6 d2d4 i8h6 d4d5 c6e5 d1d4 d7d6 c1d2 h6f5 d4e4 ============================================================================
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.