Deeper search focusing on a specific line

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xr_a_y
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Deeper search focusing on a specific line

Post by xr_a_y » Thu Nov 21, 2019 9:06 pm

Is it already a thing to consider the first part of the pv fixed when it is stable enough (let's say the first 25% of it when depth is at least 10 has not changed for the last 4 depth) and to start searching from the corresponding position (an apply that recursively).

The idea is to try to go deeper in a specific line.

Worth the try ?

Daniel Shawul
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Re: Deeper search focusing on a specific line

Post by Daniel Shawul » Sat Nov 23, 2019 12:07 am

With modern aggressively pruning searchers, it is probably already the case that very little time is spent if the PV move has no competitor.
If you do have two or more moves that are equally good, you probably want to search them equally anyway.
There is an idea forwarded for MCTS ("sufficiency threshold"), which suggests that if two or more moves score above a certain threshold (say 65%), randomly focus on one of them i.e. set exploration coefficient to 0 since you are winning anyway, and search one of them to deeper depths. If it turns out that that move is bad you can switch to the other move. You can try something like that in AB search too I guess.

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Deberger
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Re: Deeper search focusing on a specific line

Post by Deberger » Sun Dec 08, 2019 2:25 am

xr_a_y wrote:
Thu Nov 21, 2019 9:06 pm
The idea is to try to go deeper in a specific line.

Worth the try ?
IIRC, maybe 20 years ago, using fractional plies, Rebel was adding 1/4 ply for the pv.

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