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 |  Subject: Latest abrok Development Versions January 29 th Tue Jan 29, 2019 10:25 pm | |
| | Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64 | Author: Miguel Lahoz
Date: Tue Jan 29 17:32:41 2019 +0100
Timestamp: 1548779561
Change pinning logic in Static Exchange Evaluation (SEE)
This changes 2 parts with regards to static exchange evaluation.
Currently, we do not allow pinned pieces to recapture if *all* opponent
pinners are still in their starting squares. This changes that to having
a less strict requirement, checking if *any* pinners are still in their
starting square. This makes our SEE give more respect to the pinning
side with regards to exchanges, which makes sense because it helps our
search explore more tactical options.
Furthermore, we change the logic for saving pinners into our state
variable when computing slider_blockers. We will include double pinners,
where two sliders may be looking at the same blocker, a similar concept
to our mobility calculation for sliders in our evaluation section.
Interestingly, I think SEE is the only place where the pinners bitboard
is actually used, so as far as I know there are no other side effects
to this change.
An example and some insights:
White Bf2, Kg1
Black Qe3, Bc5
The move Qg3 will be given the correct value of 0. (Previously < 0)
The move Qd4 will be incorrectly given a value of 0. (Previously < 0)
It seems the tradeoff in search is worth it. Qd4 will likely be pruned
soon by something like probcut anyway, while Qg3 could help us spot
tactics at an earlier depth.
STC:
LLR: 2.96 (-2.94,2.94) [0.50,4.50]
Total: 62162 W: 13879 L: 13408 D: 34875 Elo +2.63
http://tests.stockfishchess.org/tests/view/5c4ba1a70ebc593af5d49c55
LTC: (Thanks to @alayant)
LLR: 3.40 (-2.94,2.94) [0.00,3.50]
Total: 140285 W: 23416 L: 22825 D: 94044 Elo +1.46
http://tests.stockfishchess.org/tests/view/5c4bcfba0ebc593af5d49ea8
Bench: 3937213 | Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64 | Author: Maciej Żenczykowski
Date: Tue Jan 29 17:26:24 2019 +0100
Timestamp: 1548779184
Use int8_t instead of int for SquareDistance[]
This patch saves (4-1) * 64 * 64 = 12KiB of cache.
STC
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 176120 W: 38944 L: 38087 D: 99089 Elo +1.69
http://tests.stockfishchess.org/tests/view/5c4c9f840ebc593af5d4a7ce
LTC
As a pure speed up, I've been informed it should not require LTC.
No functional change |
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