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tweack.

bench 3446432
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Vizvezdenec committed Apr 15, 2019
1 parent 1594d15 commit f236478e7387e61affadd674c091a52b3490a753
Showing with 4 additions and 0 deletions.
  1. +4 −0 src/evaluate.cpp
@@ -324,6 +324,8 @@ namespace {

if (Pt == BISHOP)
{
constexpr Bitboard boardSide (Us == WHITE? Rank1BB | FileABB | FileHBB :
Rank8BB | FileABB | FileHBB);
// Penalty according to number of pawns on the same color square as the
// bishop, bigger when the center files are blocked with pawns.
Bitboard blocked = pos.pieces(Us, PAWN) & shift<Down>(pos.pieces());
@@ -334,6 +336,8 @@ namespace {
// Bonus for bishop on a long diagonal which can "see" both center squares
if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
score += LongDiagonalBishop;
else if (!(b & mobilityArea[Us] & ~boardSide))
score -= make_score(20, 20);
}

// An important Chess960 pattern: A cornered bishop blocked by a friendly

7 comments on commit f236478

@protonspring

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replied Apr 16, 2019

Doesn't this conflict with psqt? Perhaps some changes there are needed to get this over the hump.

@Alayan-stk-2

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replied Apr 17, 2019

This must be the longest successful LTC ever at fishtest ?

Congrats :)

@Vizvezdenec

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replied Apr 17, 2019

@Alayan-stk-2 nah, there were some 250+k patches :)
@protonspring this is "somewhat" conflicting with both mobility bonus and with PSQT (well, for example, it will give penalty for every bishop with 0 mobility so effectively this patch reduces first value in bishop mobility table by (20,20)) but it doesn't directly conflict with anything.
Idea is that bishop is rarely all that useful on the side of the board and if we can't really move bishop to anywhere but the side of the board it's probably not that good of a bishop.
There of course can be a) further attempts on improving this eval term;
b) attempts to simplify it away with bishop PSQT/mobility tweak. I'm completely not against it :)

@31m059

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replied Apr 17, 2019

Congratulations!

@protonspring

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replied Apr 17, 2019

@Vizvezdenec

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replied Apr 17, 2019

I don't think that simplification is the first thing to do with this patch, maybe some improvements on top of it should be tried first (I will try one right now).

@Mindbreaker1

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replied Apr 17, 2019

Congrats!

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