Author: Dave Gomboc
Date: 00:51:21 10/08/99
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On October 07, 1999 at 23:58:44, Christophe Theron wrote: >On October 07, 1999 at 22:55:42, Dave Gomboc wrote: > >>On October 07, 1999 at 00:58:07, Christophe Theron wrote: >> >>>On October 06, 1999 at 21:52:28, Nicolas Carrasco wrote: >>> >>>>Now I am examining how my Alpha Beta cut off's are working! >>>> >>>>I would be extreamly pleased to know how many nodes your chess engine make at >>>>the initial position (if possible without move ordering) at the following >>>>depths: >>> >>>For Chess Tiger 12.0 (with move ordering and selection) the results are: >>> >>>2- 46 >>>3- 606 >>>4- 2088 >>>5- 3929 >>>6- 10102 >>>7- 31441 >>> >>> >>> Christophe >> >>Your odd/even effect is quite a bit larger than I'm used to seeing. Asymmetric >>pruning? >> >>Dave > >The odd/even effect depends on the position. For example going from level 2 to >level 3 takes a lot of work, apparently because the first sequence of capture >begins, or maybe checks (?). At that time the move ordering stored from the >previous level becomes completely wrong apparently. > >If you look at the increasing (cumulative) branching factor you get: > >2 to 3: 14.0x >3 to 4: 3.4x >4 to 5: 1.9x >5 to 6: 2.6x >6 to 7: 3.1x > >So this is not an odd/even effect. Sometimes the odd to even is high, but >sometimes the even to odd is higher. > >As I said, the behaviour is different in each position. Also, at deeper depth it >tends to be smaller. > > > Christophe I guess that just shows that concrete calculation stacks up well against human intuition. ;-) Dave
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