Author: Rafael Andrist
Date: 09:50:21 04/23/01
Go up one level in this thread
On April 23, 2001 at 12:15:09, Antonio Dieguez wrote: >On April 23, 2001 at 12:04:05, Rafael Andrist wrote: > >>On April 23, 2001 at 11:43:33, Antonio Dieguez wrote: >> >>>A branching factor around 9 is too high for an alphabeta-search even without >>>prunning and without hashtable. Why are you using infinite window? try using >>>small and null windows and see what happen first. >>>Anyway you say "The use of Iterative Deepening didn't change much" so before how >>>you calculated the branching factor? The definition I use is nodes iteration >>>x+1/nodes iteration x, if you are using the other definition that I don't >>>renember wich is, please forgive my unusefull post. >> >>I calculate a virtual branching factor, which is the same for each depth (in >>reality, it's different). >> >>b := branching factor >>d := depth >>n := nodes >> >>b = n ^ (1 / d) >> >>so b ^ d gives n >> >>[the ^ means the power function, not the ANSI-Xor] >> >>Rafael B. Andrist > >This is a weird way because is difficult to compare things isn't? suppose the >root position has a lot of mobility and possible moves(72) > >imagine this: > >[1] 100 >[2] 200 >[3] 400 >[4] 800 >[5] 1600 >[6] 3200 >[7] 6400 > >and a position with a low mobility in the root, imagine this: > >[1] 10 >[2] 20 >[3] 40 >[4] 80 >[5] 160 >[6] 320 >[7] 640 > >using the def I use it's factor 2 in both cases, seems fine. But using yours it >turns veeeeery weird and different. You forget that you have a branching factor of 100 at the root is ex. 1 and one of 10 in ex. 2. Using "my" definition, it isn't very different: ex.1: 3.50 ex.2: 2.52 But all the things about mobility are not relevant, because I compare two identical positions, one searched with and one without iterative deepening. a practical example from my prog (with bad move sorting): N: nodes in normal search Q: nodes in quiescence search H: number of successful hash access' with iterative deepening: 1 ply Sb1-c3 N: 43 Q: 15 H: 0 Value: 5 2 ply Lf1-b5+ N: 462 Q: 323 H: 9 Value: -1 3 ply e4xd5 N: 2695 Q: 3074 H: 106 Value: 2 4 ply e4-e5 N: 24624 Q: 20999 H: 877 Value: -5 5 ply e4xd5 N: 104066 Q: 92941 H: 4173 Value: 1 b = 10.08 (I've calculated it only with the nodes in normal search) without iterative deepening: 5 ply e4xd5 N: 148437 Q: 127757 H: 2995 Value: 1 b = 10.82 Rafael B. Andrist
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