Author: Landon Rabern
Date: 02:01:13 12/10/00
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On December 09, 2000 at 22:17:24, Robert Hyatt wrote: >On December 09, 2000 at 15:40:28, Landon Rabern wrote: > >>On December 09, 2000 at 00:15:43, Robert Hyatt wrote: >> >>>On December 08, 2000 at 23:13:13, Landon Rabern wrote: >>> >>>>On December 08, 2000 at 22:22:24, Robert Hyatt wrote: >>>> >>>>>On December 08, 2000 at 20:41:40, Landon Rabern wrote: >>>>> >>>>>>On December 08, 2000 at 16:16:01, Robert Hyatt wrote: >>>>>> >>>>>>>On December 08, 2000 at 13:21:21, Peter Fendrich wrote: >>>>>>> >>>>>>>>On December 08, 2000 at 13:06:43, Robert Hyatt wrote: >>>>>>>> >>>>>>>>>On December 08, 2000 at 12:56:09, Peter Fendrich wrote: >>>>>>>>> >>>>>>>>>>I looking for a measurement for move generation performance. >>>>>>>>>> >>>>>>>>>>Do you think FH/CountNodes, where FH is number of times the first generated move >>>>>>>>>>was a Fail High, is a good measurement? >>>>>>>>>>Do you have some other? >>>>>>>>>>What's your figures? >>>>>>>>>>I get some 50% and I have a feeling it's to low. >>>>>>>>>> >>>>>>>>>>//Peter >>>>>>>>> >>>>>>>>> >>>>>>>>>The critical statistic I measure in crafty is this: "For any position where >>>>>>>>>I 'fail high' (return a score >= beta) what percentage of the time does it >>>>>>>>>happen on the _first_ move?" I generally average 92%. Anything over 90% is >>>>>>>>>reasonable. Anything less means move ordering needs work. >>>>>>>> >>>>>>>>OK, it seems logical. I have in princple 3 types of FH: >>>>>>>> 1) Hash table (without moving) >>>>>>>> 2) Null Move >>>>>>>> 3) Ordinary moves (including the hash table move) >>>>>>>> >>>>>>>>Do you include all these cases? >>>>>>>>With only the third case counted I'm well over 90% >>>>>>>> >>>>>>>>//Peter >>>>>>> >>>>>>> >>>>>>>Only 1 and 3. 2 is done at a different place in the search and doesn't >>>>>>>really count in "move ordering". >>>>>>> >>>>>>>Actually, the way you wrote it, only 3 counts. for 1) you are not searching >>>>>>>a move, so that can't be counted. 2) doesn't count either... >>>>>> >>>>>>I am getting about 80% on this, is this real bad? I am not doing internal >>>>>>interative deepening, do you think this will help a lot, or do you think there >>>>>>is something else wrong. >>>>>> >>>>>>I try moves in this order: >>>>>> >>>>>>hash/pv >>>>>>all captures sorted MVV/LVA >>>>>>two killers >>>>>>3 history scan moves >>>>>>the rest >>>>>> >>>>>> >>>>>>Regards, >>>>>> >>>>>>Landon W. Rabern >>>>> >>>>> >>>>>Your MVV/LVA ordering is probably the culprit. Because you are trying moves >>>>>like QxP, even though the pawn is defended... and you try those _before_ you >>>>>try the move that will ultimately fail high (a killer or history move). >>>>> >>>>>I would still expect it to be higher than 80%... but that might be about right >>>>>with MVV/LVA. You get some of that back in terms of faster ordering, and you >>>>>get some back because the bad captures get cut off quickly by null-move >>>>>searches... but it could be better... >>>> >>>>Ok, I switched to using my SEE to order the moves, but did not do the bad >>>>captures last yet(no time yet), just did them all at once, but ordered with SEE. >>>> Now I get about 86%-89%. Do you think I should be able to get over 90% by >>>>doing bad captures last? >>>> >>>>Regards, >>>> >>>>Landon W. Rabern >>> >>> >>>Very possibly... >> >>Are you counting beta cutoffs in the q-search as well? > > >No... it doesn't make a lot of sense there. I keep the statistic as it >is important for parallel search performance. What I do is this: when I >fail high at a normal search node, I increment a counter. If the fail high >is on the _first_ move tried, I increment a second counter. The closer the >second counter gets to the first counter, the better move ordering is... right thats what I am doing. I moved bad captures to be the last moves tried now I am averaging 91%. I am now starting on a neural network static eval for independent study. I can't believe they are actually going to give me credit for working on my chess program. Regards, Landon W. Rabern
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