Re: [gnugo-devel] possible reading.c speedups

[Arend Bayer]

> I made a crude experiment with history heuristic once but without any
> measurable success. Might have been because the implementation was too
> bad.

I think the difficult part will be finding a good heuristic which
successful moves in other variations are still relevant. In chess,
this seems a little easier: the mere fact that the move "From X to Y"
is still possible should already be a good hint that it is also relevant.
(Chess engines store the history table as a 64x64 array.) An idea might be
to make the history table as an array history[max_depth][BOARDMAX] and only
take into account moves that were successful at a similar depth. Hmm.

> > Some of these techniques should be applicable to owl as well, where
> > they might enable us to increase the maximal number of moves tried.
> 
> I don't think you mean what you're saying here. More sophisticated
> move selection should reduce the *number of moves* that can be tried
> within a given amount of time, since each move takes more time to
> generate. What it increases is rather the size of the tree which is
> analyzed.
> 
What I meant to say is: Maybe we could increase accuracy of owl by 
changing MAX_MOVES from 3 to 4 (or increase the depth where branching
still happens etc.), without loosing speed or getting more owl node limit
cut offs compared to today.

Arend