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Isolated pawns tweak

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Give opposed doubled isolated pawns only the Doubled penalty.
The other isolated pawns get the Isolated penalty and the WeakUnopposed penalty.
The popcount condition has been replaced with an opposed check,
which is non-functional, but probably gives a speed-up.

Passed STC (https://tests.stockfishchess.org/tests/view/5ed0f0f0042fa6d77c3552f5):
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 121832 W: 23562 L: 23195 D: 75075
Ptnml(0-2): 2092, 14064, 28313, 14279, 2168

LTC: (https://tests.stockfishchess.org/tests/view/5ed22e40042fa6d77c355387)
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 103368 W: 13232 L: 12768 D: 77368
Ptnml(0-2): 693, 9484, 30919, 9842, 746

closes https://github.com/official-stockfish/Stockfish/pull/2706

Bench: 4085694
This commit is contained in:
ElbertoOne
2020-05-31 16:39:03 +02:00
committed by Joost VandeVondele
parent 616eb60008
commit 8c3d9d996a
1 changed files with 5 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/pawns.cpp
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@@ -145,13 +145,13 @@ namespace {
else if (!neighbours) else if (!neighbours)
{ {
score -= Isolated if ( opposed
+ WeakUnopposed * !opposed; && (ourPawns & forward_file_bb(Them, s))
if ( (ourPawns & forward_file_bb(Them, s))
&& popcount(opposed) == 1
&& !(theirPawns & adjacent_files_bb(s))) && !(theirPawns & adjacent_files_bb(s)))
score -= Doubled; score -= Doubled;
else
score -= Isolated
+ WeakUnopposed * !opposed;
} }
else if (backward) else if (backward)