Re: Suggestion for change

[Simon Waters]

Tim Bedding wrote:
> 
> In the following position (lower case means black)
>   4k3/2B1q1pp/8/3p1Qp1/8/8/2P2PPP/6K1
> White is ahead by a bishop and should, in my
> view, exchange queens in order to simplify
> the position.

Given the position with 40 moves in 5 minutes the test release
of 5.05 plays Qe5 at about 40 seconds on this hardware (P200
equivalent), as you suggest.

Evaluate already has a simplistic trade down bonus, might be
scope for tuning it, but you'd want several endgame positions.

I suspect that specifying ply depth might be having an adverse
approach to this position, stick with time.

There are also some tactical possibilities in this position for
white to gain material, which I'd expect a computer might prefer
given enough time, as given a chance those pawns might fall with
check, that would be a typical computer approach to endgame
tactics, and isn't objectively worse (if you are a computer and
don't blunder badly) I think.

One more obvious area for "evaluate" going wrong, is I believe
it's insistence on not moving pawns in front of the king, even
when back row mate threats start becoming a significant part of
the analysis. I note in this position no pawns have been moved
in front of the computers king! Whilst not moving them lightly
is good chess, GNU is a tad dogmatic on these things!