Author: Brian Richardson
Date: 07:40:28 06/01/00
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On June 01, 2000 at 09:17:59, Bas Hamstra wrote: >On May 31, 2000 at 19:24:37, Brian Richardson wrote: > >>On May 31, 2000 at 18:02:42, Bas Hamstra wrote: >> >>I did some quick tests with Tinker (of course, the search "ecosystem" of each >>program will be very different). Normally, Tinker probes the hash table, then >>does the hash move (if any), then killers, then generates moves, and so on. > >I hope you DO captures before killers? Doing that, killers should be a big win. >But note that if you already do history, that the extra gain of killers is far >less, because both try to achieve the same. No, I don't generate any moves (captures or non-caps) until after killers (or the hash move) are tried. However, I don't use killers (or hash move) in q-search, just full-width. > >>For the following, one history table for both sides is always used. Tested on >>five positions (opening, two from WAC, one from Fine and one BT2630): >>1) Turning hash moves off--usually 2x slower, up to 10x slower, one test 5% >>faster. >>2) Turning killers off (keeping 2 moves)--very mixed results: same, or up to 30% >>faster or up to 10x slower (Fine16) > >This 10x slower is counter intuitive to me. If you don't use history sorting >killers should be a big win. If you do, it is a small win overall. It was a big surprise to me too. The tests above were all with history. > >>3) Turning off both--better than no killers, but worse than no hash move. >> >>To my surprise, Tinker's WAC 300 score went UP with no killers. Again, this is with history (disabling history slows everything down A LOT). I may try some >>self-play tests with and without killers. >> >>Brian Richardson > >Maybe you could also include: a) History and no killers This was test 2 above >and b) Killers and no history? No history is MUCH slower. >I suspect that if you already use 2 killers the gain of adding history >is small. And since killers are cheaper I don't use history sorting... > > >Regards, >Bas. What I'm starting to see is that history is better than killers. The history overhead is very small, since it is part of the move ordering score along with MVV/LVA anyway. Some early self-play tests showed killers better at time 2 1 and no killers better at 5 0. Will run some more tests tonight. Brian
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