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SEE on non-capture moves in main search
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Tord Romstad



Joined: 08 Mar 2006
Posts: 1750
Location: Oslo, Norway
PostPost subject: Re: SEE on non-capture moves in main search    Posted: Fri Mar 30, 2007 10:29 pm Reply to topic Reply with quote
bob wrote:
Again, read _what_ I wrote. QxR wins a pawn (queen for 2 rooks). That is a winning exchange by SEE. It should _not_ be searched prior to RxN which wins a knight.

Perhaps, but this particular case (which is not at all common in practise) is one of the very few cases where it is no longer possible to capture the hanging piece after the initial exchange. The superior performance of MVV/LVA in the more common cases far outweigh the superior performance of SEE in cases like Q vs R+R exchanges, in my experience.

An unrelated point: Although two rooks are usually worth slightly more than a queen, I've found that it works better to treat Q vs R+R as an equal capture in the SEE. Here I am not talking about move ordering, but about not pruning too many promising captures in the quiescence search: In practise, giving two rooks for a queen seems to be strong more often than giving a queen and a pawn for two rooks. YMMV, as always.

I use piece values of 1, 3, 3, 5 and 10 in my SEE.

Quote:
MVV/LVA is the only viable solution when using special-purpose hardware.


Clearly not. It seems clear that this is something which depends on the program, but it is an indisputable fact that several authors of decent chess programs (Fruit, Glaurung, Joker, and certainly many others) have experimented with both approaches and found that MVV/LVA move ordering for winning and equal captures is better than SEE. I have tested this very thoroughly the last few months, and there is no doubt about what works best for me. The difference is small, but consistent across all my tests.

Perhaps Fruit, Glaurung and Joker are not quite in the same league as Crafty, but they are not so far behind that you can dismiss our experimental results as incorrect or worthless simply because they do not agree with your results. For some reason, our programs behave differently from yours in this respect. It would be interesting to know why, but we shall probably never find out.

Tord
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Subject Author Date/Time
SEE on non-capture moves in main search Gary Wed Mar 28, 2007 11:25 pm
      Re: SEE on non-capture moves in main search Robert Hyatt Thu Mar 29, 2007 1:17 am
            Re: SEE on non-capture moves in main search Tord Romstad Thu Mar 29, 2007 10:03 am
                  Re: SEE on non-capture moves in main search ed Thu Mar 29, 2007 1:34 pm
                        Re: SEE on non-capture moves in main search Sam Hamilton Fri Mar 30, 2007 12:07 am
                        Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 11:46 am
                  Re: SEE on non-capture moves in main search Robert Hyatt Thu Mar 29, 2007 9:35 pm
                        Re: SEE on non-capture moves in main search H.G.Muller Thu Mar 29, 2007 10:27 pm
                              Re: SEE on non-capture moves in main search Robert Hyatt Fri Mar 30, 2007 12:05 am
                                    Re: SEE on non-capture moves in main search H.G.Muller Fri Mar 30, 2007 6:50 am
                                          Re: SEE on non-capture moves in main search Robert Hyatt Fri Mar 30, 2007 9:27 pm
                                                Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 10:29 pm
                                                      Re: SEE on non-capture moves in main search Robert Hyatt Sun Apr 01, 2007 1:51 am
                                                            Re: SEE on non-capture moves in main search Tord Romstad Sun Apr 01, 2007 7:54 am
                                                                  Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 1:57 am
                                                            Re: SEE on non-capture moves in main search H.G.Muller Sun Apr 01, 2007 10:22 am
                                                                  Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 2:05 am
                                                                        Re: SEE on non-capture moves in main search H.G.Muller Mon Apr 02, 2007 12:31 pm
                                                                              Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 3:56 pm
                                                                                    Re: SEE on non-capture moves in main search Steven Edwards Mon Apr 02, 2007 4:44 pm
                                                                                          Re: SEE on non-capture moves in main search H.G.Muller Mon Apr 02, 2007 4:59 pm
                                                                                          Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 6:44 pm
                                                                                          Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 6:40 pm
                                                                                    Re: SEE on non-capture moves in main search H.G.Muller Mon Apr 02, 2007 4:53 pm
                                                Re: SEE on non-capture moves in main search H.G.Muller Sat Mar 31, 2007 8:38 am
                                                      Re: SEE on non-capture moves in main search Robert Hyatt Sun Apr 01, 2007 1:59 am
                                                            Re: SEE on non-capture moves in main search Tord Romstad Sun Apr 01, 2007 7:58 am
                                                                  Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 3:57 pm
                                                                  Re: SEE on non-capture moves in main search Peter Fendrich Mon Apr 02, 2007 5:19 pm
                                                                        Re: SEE on non-capture moves in main search Robert Hyatt Mon Apr 02, 2007 6:46 pm
                                                                        Re: SEE on non-capture moves in main search Tord Romstad Mon Apr 02, 2007 6:51 pm
                                                                              Re: SEE on non-capture moves in main search Peter Fendrich Mon Apr 02, 2007 7:53 pm
                                                                                    Re: SEE on non-capture moves in main search H.G.Muller Mon Apr 02, 2007 9:01 pm
                                                                                          Re: SEE on non-capture moves in main search Peter Fendrich Mon Apr 02, 2007 9:30 pm
                                                                                          Re: SEE on non-capture moves in main search H.G.Muller Tue Apr 03, 2007 8:46 am
                                                                                          Re: SEE on non-capture moves in main search Peter Fendrich Tue Apr 03, 2007 10:29 am
                                                                                          Re: SEE on non-capture moves in main search Robert Hyatt Tue Apr 03, 2007 9:23 pm
                                                                                          Re: SEE on non-capture moves in main search Tord Romstad Wed Apr 04, 2007 2:38 pm
                                                                                          Re: SEE on non-capture moves in main search Peter Fendrich Wed Apr 04, 2007 7:49 pm
                                                                                          Re: SEE on non-capture moves in main search Tony Tue Apr 03, 2007 10:54 am
                                                                                          Re: SEE on non-capture moves in main search Robert Hyatt Tue Apr 03, 2007 9:24 pm
                                                                                          Re: SEE on non-capture moves in main search H.G.Muller Tue Apr 03, 2007 9:29 pm
                                    Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 11:40 am
                              Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 11:54 am
                                    Re: SEE on non-capture moves in main search H.G.Muller Fri Mar 30, 2007 1:28 pm
                                          Re: SEE on non-capture moves in main search H.G.Muller Fri Mar 30, 2007 4:41 pm
                        Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 11:30 am
                              Re: SEE on non-capture moves in main search Uri Blass Fri Mar 30, 2007 11:50 am
                                    Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 10:32 pm
                              Re: SEE on non-capture moves in main search H.G.Muller Fri Mar 30, 2007 12:16 pm
                              Re: SEE on non-capture moves in main search Robert Hyatt Fri Mar 30, 2007 9:32 pm
                                    Re: SEE on non-capture moves in main search Tord Romstad Fri Mar 30, 2007 10:00 pm
      Re: SEE on non-capture moves in main search Mark Lefler Thu Mar 29, 2007 6:30 am
      Re: SEE on non-capture moves in main search H.G.Muller Thu Mar 29, 2007 9:28 am
            Re: SEE on non-capture moves in main search Tord Romstad Thu Mar 29, 2007 10:13 am
                  Re: SEE on non-capture moves in main search H.G.Muller Thu Mar 29, 2007 12:03 pm
                        Re: SEE on non-capture moves in main search Tord Romstad Thu Mar 29, 2007 12:39 pm
                              Re: SEE on non-capture moves in main search H.G.Muller Thu Mar 29, 2007 2:15 pm
                                    Re: SEE on non-capture moves in main search Zach Wegner Thu Mar 29, 2007 9:10 pm
                  Re: SEE on non-capture moves in main search Steven Edwards Thu Mar 29, 2007 2:18 pm
                  Re: SEE on non-capture moves in main search Rob Sun Apr 01, 2007 6:01 pm
      Re: SEE on non-capture moves in main search Gary Sun Apr 01, 2007 8:26 am
      Re: SEE on non-capture moves in main search Markoff Thu Apr 05, 2007 11:25 pm
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