Stockfish

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Homayoun
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Joined: Tue Mar 21, 2023 4:57 pm
Real Name: Homayoun

Stockfish

Post by Homayoun » Thu Sep 07, 2023 8:20 pm

Author: Stéphane Nicolet
Date: Sun Sep 3 09:28:16 2023 +0200
Timestamp: 1693726096

Introduce simple_eval() for lazy evaluations

This patch implements the pure materialistic evaluation called simple_eval()
to gain a speed-up during Stockfish search.

We use the so-called lazy evaluation trick: replace the accurate but slow
NNUE network evaluation by the super-fast simple_eval() if the position
seems to be already won (high material advantage). To guard against some
of the most obvious blunders introduced by this idea, this patch uses the
following features which will raise the lazy evaluation threshold in some
situations:

- avoid lazy evals on shuffling branches in the search tree
- avoid lazy evals if the position at root already has a material imbalance
- avoid lazy evals if the search value at root is already winning/losing.

Moreover, we add a small random noise to the simple_eval() term. This idea
(stochastic mobility in the minimax tree) was worth about 200 Elo in the pure
simple_eval() player on Lichess.

Overall, the current implementation in this patch evaluates about 2% of the
leaves in the search tree lazily.

--------------------------------------------

STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 60352 W: 15585 L: 15234 D: 29533 Elo +2.02
Ptnml(0-2): 216, 6906, 15578, 7263, 213
https://tests.stockfishchess.org/tests/ ... ffae366209

LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 35106 W: 8990 L: 8678 D: 17438 Elo +3.09
Ptnml(0-2): 14, 3668, 9887, 3960, 24
https://tests.stockfishchess.org/tests/ ... 4e3f04c0e7

verification run at VLTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 74362 W: 19088 L: 18716 D: 36558 Elo +1.74
Ptnml(0-2): 6, 7226, 22348, 7592, 9
https://tests.stockfishchess.org/tests/ ... 4e3f04d3ae

All three tests above were run with adjudication off, we also verified that
there was no regression on matetracker (thanks Disservin!).

https://abrok.eu/stockfish/

Note: From now on I will share only stockfish devs that show great Elo peogress.

Homayoun
Posts: 1577
Joined: Tue Mar 21, 2023 4:57 pm
Real Name: Homayoun

Re: Stockfish

Post by Homayoun » Thu Sep 07, 2023 8:36 pm

Note: I will share only stockfish devs that show total elo progress more than 0.5 ( total elo > 0.5).

Anton101
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Real Name: A. Ces
Location: México

Re: Stockfish

Post by Anton101 » Fri Sep 08, 2023 2:43 pm


Homayoun
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Re: Stockfish

Post by Homayoun » Fri Sep 08, 2023 3:00 pm

Anton101 wrote:
Fri Sep 08, 2023 2:43 pm
This is a new great patch...

https://tests.stockfishchess.org/tests/ ... e8259a7010
Thanks

Anton101
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Real Name: A. Ces
Location: México

Re: Stockfish

Post by Anton101 » Fri Sep 08, 2023 3:04 pm

;)

Regards.

Sedat Canbaz
Posts: 1978
Joined: Wed Jun 21, 2023 6:29 am

Re: Stockfish

Post by Sedat Canbaz » Fri Sep 08, 2023 3:41 pm

Thank you friends for all these updates..
Otherwise I can not imagine without you!

Keep up the good work

Homayoun
Posts: 1577
Joined: Tue Mar 21, 2023 4:57 pm
Real Name: Homayoun

Re: Stockfish

Post by Homayoun » Fri Sep 08, 2023 6:38 pm

Sedat Canbaz wrote:
Fri Sep 08, 2023 3:41 pm
Thank you friends for all these updates..
Otherwise I can not imagine without you!

Keep up the good work
Thanks too, Mr. Sedat. My feeling is same too. I can’t continue without the help and support of good friends, like you and other friends too.

All the bests

Anton101
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Real Name: A. Ces
Location: México

Re: Stockfish

Post by Anton101 » Fri Sep 08, 2023 8:43 pm

Two new nets that so far promise...Patience...

https://github.com/linrock/Stockfish/co ... e1fdab7e2d

and, https://github.com/linrock/Stockfish/co ... 6cdcc727c4

By Linrock as usual.

;)

ZamChess
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Joined: Sun Dec 19, 2021 10:24 am

Re: Stockfish

Post by ZamChess » Sat Sep 09, 2023 7:00 am

Thanks

Anton101
Posts: 718
Joined: Sat Jun 10, 2023 6:46 pm
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Re: Stockfish

Post by Anton101 » Sat Sep 09, 2023 6:27 pm


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