Actually, the higher the resolution of your evaluation function, the better it plays - at least at the same depth. However there is a bit of a tradeoff in speed for this. Presumably less tie score which can produce cutoffs.Lyudmil Tsvetkov wrote:Hi Richard.Richard Allbert wrote:Totally agree.
Computers are strong, no doubt, especially with tactics, but I think far too much emphasis is put on their evalutations.
For example, say after move 14 you see +0.50 from one engine playing another -> after 10 more moves this score is usually different.
This means by definition the +0.50 was maybe not accurate afterall.
iirc on Houdini's website (or an interview with CB) Houdart said that Houdini wins 90% of games where it thinks it is > +0.8 in the middlegame.
That's a a big margin of Evaluation error, and thus I never understand the obsession with differentiating lines differing by 0.1
This was especially so during the London Chess Classic - many observers were constantly claiming "mistakes" by the players, due to a +0.5 swing in evaluation by their engine.
Interestingly, the GM's commentating were quite the opposite - they rarely believed the computer assessment, unless it was massively in favour of one player (over +2.0 or so), or tablebases were accessed. Otherwise they used them for tactics checking.
Richard
The better an engine's evaluation is, the less it is going to jump (swing).
Older engines like Fritz, etc., would register even more astounding jumps in their evaluations. But, next to evaluations of humans (and humans still evaluate subliminally, as well compute subliminally millions of variations per second, just as computers do), engine evaluations are simply outstanding. If you were able to see jumps in human evaluations (you could judge for them by seeing the larger quantity of mistakes in comparison to computers), you would know, that human evaluations are jumping sometimes not by half a pawn, but by much bigger margins. The inability to foresee a tactical shot, for example, should register a jump measured by a couple of very whole pawns.
I think that not only 0.1 pawns make the difference, but even 0.01 pawns. In chess every single detail counts. An engine showing +30cps and facing an opponent of roughly equal strength has actually very good chances to gradually increase its score up to a winning point, simply because the number of available variations for the defending side still maintaining the score would decrease with every passing move. Chances are much bigger that an advantage in score will be increased, than they are that it would decrease or at least be maintained.
That is why it is important to evaluate every single detail.
Best regards, Lyudmil
A resolution of 1/50 is probably as low as is reasonable. Komodo uses 1/100 (internally 1/1000 which is rounded before being passed to the search) and it's common to use 1/256.
It's not that computers can actually make these super fine distinctions, but it does seem to have an impact to try to.