Author: Bert van den Bosch
Date: 10:12:29 03/15/04
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On March 15, 2004 at 00:11:25, Michel Langeveld wrote: >On March 14, 2004 at 15:40:43, Bert van den Bosch wrote: > >>On March 14, 2004 at 12:31:49, Michel Langeveld wrote: >> >>>On March 14, 2004 at 06:58:50, Bert van den Bosch wrote: >>> >>>>I was wondering when you can decide to make a move which was computed at a ply n >>>>alpha beta, knowing that a 'move now' came while searching an n-ply alpha beta. >>>>You can also make the move computed at ply n-1 (the previous alpha beta tree in >>>>the iterative deepening proces), but I guess sometimes you have found a pretty >>>>nice move at the ply n tree. Is it a matter of taste? >>>> >>>>greetings Bert >>> >>>If the 2nd move is stronger as the first move when search N ply I update the >>>move to play. If time is finished and ply N is not totally calculated to the end >>>it knows that the 2nd move is the strongest one. >> >> >>But this second move can be a bad move, maybe with some bad luck losing a queen >>or so, while the move at ply n-1 doesn't. > >It works as follows: > >Ply 1 >Move 1/4 d4 = 0.40 >Move 2/4 e4 = 0.56 [move is sorted higher-new movelist is e4 d4 f4 Qxf7] >Move 3/4 f4 = 0.56 >Move 4/4 Qxf7+ = 2.56 [move is sorted higher-new movelist is Qxf7 e4 d4 f4] > >Ply 2: >Move 1/4 Qxf7 = -4.00 (Qxf7 is searched first, because this was the best move) > (if the time is up now ... the time is extended] >Move 2/4 e4 = 0.54 >[time is up - and not all move have been examined] > >Now e4 will be played > >The extending if time can be quite ggressive. Some programs can use 1/4 of their >time. I think it's even legal to play directly move e4, because this move was a >lot better as -4.00 at ply 1. Searching futher is also possible, because Ply 2 >seems to be an important play. If the time is up before e4 can be found on ply 2 >then a program has to play e4! This is a timemanagement issue I think in each >program it is implemented different. Ok I understand, well I'll just play a bit with it
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