Author: Dann Corbit
Date: 15:19:49 03/17/04
Go up one level in this thread
On March 17, 2004 at 16:28:30, Mikael Bäckman wrote: >On March 17, 2004 at 16:22:42, Dann Corbit wrote: > >>On March 17, 2004 at 16:14:40, Mikael Bäckman wrote: >>> >>>Hi, >>> >>>I ran some tests with history and different methods of aging it, as discussed in >>>this thread: >>> >>>http://www.talkchess.com/forums/1/message.html?354812 >>> >>>I picked 15 test positions from this years Linares tournament. 10 positions are >>>from move 20 and 5 from move 40. I didn't study the positions much before >>>selecting them. >>> >>>I used 90 seconds per position as I didn't know how deep I could search without >>>spending days on this... First I ran a test without historytables, to get a >>>depth to compare the other tests to. Most of the depths were completed in 20-60 >>>seconds. Perhaps a bit shallow, but it gives an idea of the performance. >>> >>>I use a side-piece-to historytable or history[side][piece][to] and I use at most >>>8 history moves at a node. After that I try the moves in the order they are >>>generated. >>> >>> >>>Test1 = No History >>>Test2 = History >>>Test3 = History - root aging >>>Test4 = History - age as soon as a history score gets larger than 10000. >>>Test5 = Same as 2 but with pawnmoves generated after all other moves. Included >>>this for fun, but it seems to work best. :) >>> >>>Aging was done by dividing the values in the history tables with 8. >>>Nodecounts are in thousands. >>> >>>Pos D Test1 Test2 Test3 Test4 Test5 >>>-------------------------------------------------- >>>01 12 27960 22044 21481 21923 21954 >>>02 12 37488 31165 31706 25631 26492 >>>03 10 34388 24471 24652 29455 24225 >>>04 12 25099 21307 23497 20555 23460 >>>05 13 30665 22026 22288 22156 21798 >>>06 10 16141 12861 13447 13050 13576 >>>07 14 44136 32362 31157 32776 32958 >>>08 14 39848 38378 39681 38337 28706 >>>09 11 31083 21410 24811 25470 25403 >>>10 12 38152 29568 28020 29394 25669 >>>11 13 29184 25017 27149 24854 23437 >>>12 13 52650 27674 24784 26427 25901 >>>13 14 58192 38986 41854 37978 41428 >>>14 13 50823 45372 41400 41283 45473 >>>15 13 63876 33226 32296 33651 32625 >>>-------------------------------------------------- >>> 579685 425867 428223 422940 413105 >>> (136%) (100%) (101%) (99%) (97%) >>> >> >>A 40% improvement for history heuristic is well above average improvement, I >>think. >> >>Did you have hashing and other move ordering techniques in play? I think not. >>If you have hashing operational, I would expect less than 25% improvement. > > >Yes. >I sort moves by: > >1. Hash >2. Good captures >3. Equal captures >4. Killers >5. History >6. Losing captures > >I use SEE for captures. > > >>What happens when you have all of your move ordering techqniques in use and then >>you change only the history heuristic? > >All moveordering techniques were in use. The above happens. :) That is very surprising. Do you use all hashed pv nodes where depth is >= target depth? A 40% reduction is very striking.
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