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What is your experience with PVS + Aspiration window?
Is there a big difference between use aspiration window or not use it?

Fabio Gobbato wrote:What is your experience with PVS + Aspiration window?
Is there a big difference between use aspiration window or not use it?

No. But there is a difference. Most of these kinds of things are very small, but add up a bunch of small gains and you end up with a larger gain.

The best kind of position to see the gain is to find a position where there are LOTS of lines that lead to mate, but none of them are forced. Typically such lines violate move ordering pretty well since mates do not follow any rational move orders for the most part. I used to have one, but it was lost years ago. The advantage for aspiration search will become obvious quickly, and in such a position it turns into a really big savings since it allows you to quickly prune / toss out all the mates you find since they will lie outside the aspiration window and they are not forced...

I ran some tests and aspiration windows were worth about 10 elo for my engine(rating about 2750). I haven't tuned the values at all so there is maybe 5-10 elo there, so in total aspiration windows are worth maybe 20 elo. That's not a huge amount but it's not a little sum either.

Fabio Gobbato wrote:What is your experience with PVS + Aspiration window?
Is there a big difference between use aspiration window or not use it?

Here is Deuterium test result, TC 40/30s around (1/4 CCRL 40/4), engines
take both side of start positions. D98 is not using aspiration windows.