Re: Error while generating bearoff database

[Øystein Schønning-Johansen]

Yes, it is bad. I'm in the process of quantifying some numbers on this. I'll see if I can post some of my findings.

I don't think it is the fixed array size that matters. 32 should be big enough, I believe.

However, to me it looks like the 2-sided effect is dominating. That is, the best move is depending on the board setup of the opponent player and not only the player's board setup. Of course this is taken into account somewhat even with one-sided bearoff databases with full probability distributions, however it still gets wrong, and to me it looks like this small incorrectness is not only limited to positions with just a few rolls left, but is rather propagated back to longer races.

(I'm still in the phase of investigating this, and I'll see if I can make a better statement and back it up with some examples.)

-Øystein

On Tue, Oct 6, 2020 at 11:02 PM Philippe Michel <philippe.michel7@free.fr> wrote:

On Tue, Oct 06, 2020 at 09:59:20AM +0200, Øystein Schønning-Johansen wrote:

> A huge onesided non-contact database like this will misplay a lot of
> positions.

Is it really that bad ?

I thought that, as long as one does not use shortcuts like the
--no-gammons and --normal-dist options, one-sided databases were very
accurate.

Is it because the probabilites arrays size, at 32, is too small for long
races ?