What is Fruit? Fabien explains!

[Uri Blass]

Wouldn't a simple one ply search match betwwen Crafty and Fruit say who has the better eval? Of course you would have to make sure they both have the same extensions so search does not matter. If anyone does this, let me know the results. I might just try it myself... 1 ply games go very fast!

Mark

I do not think that one ply search match can prove which evaluation is better.

The question if some evaluation is better may be dependent on the search algorithm and on the time control.

Note also that I think that speed is also relevant to decide about the quality of evaluation otherwise I can define my evaluation to be result of 10 ply search and have the best evaluation.

My definition of superiority is that evaluation A is superior to evaluation B
if having evaluation A is better in terms of chess results relative to evaluation B.

The only convincing way to demonstrate that fruit's evaluation is better than Crafty's evaluation can be done by implementing fruit's evaluation in Crafty's code and showing that Crafty with fruit's evaluation beat original Crafty.

Uri

I am not a programmer, but it seems to me that evaluation and search cannot be meaningfully separated; that what lines a programmer chooses to extend or prune could be based on his particular evaluation. For example a program with very extensive check extensions might be less inclined to have king safety terms within the evaluation itself.

This is exactly the reason that I say that there is only one proof for superiority of evaluation of program A relative to program B.

If you implement evaluation of program A in the data structure of program B and get an improvement then it means that A's evaluation is better than B.

If you do not get an improvement it does not prove that A's evaluation is not better than B's evaluation.

Uri