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MobilityArea (simplified)

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Based off of Pull request #383:

Include squares occupied by some pawns in the MobilityArea
a) not blocked
b) on rank 4 and above
c) or captures

Passed STC
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 8157 W: 1644 L: 1516 D: 4997

And LTC
LLR: 2.97 (-2.94,2.94) [0.00,6.00]
Total: 26086 W: 4274 L: 4051 D: 17761

-----------

Then, a simplification test failed, trying to remove b and c)
LLR: -2.95 (-2.94,2.94) [-3.00,1.00]
Total: 6048 W: 1117 L: 1288 D: 3643

Another simplification test, was run to remove just (c)
Passed STC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 28073 W: 5364 L: 5255 D: 17454

And LTC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 34652 W: 5448 L: 5348 D: 23856

A parameter tweak test showed that changing b) for "on rank 3 and above"
does not work
LLR: -2.95 (-2.94,2.94) [0.00,4.00]
Total: 5233 W: 937 L: 1077 D: 3219

Finally, a small rewrite, and we have this version

Include squares occupied by some pawns in the MobilityArea which are
a) not blocked
b) on rank 4 and above

Bench: 8977899

Resolves #385
This commit is contained in:
Alain SAVARD
2015-07-30 00:47:51 +08:00
committed by Gary Linscott
parent 51330414c4
commit 4a6d59c6c7
1 changed files with 12 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
src/evaluate.cpp
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@@ -701,9 +701,18 @@ namespace {
ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING];
ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING];
// Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king
Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };
// Pawns blocked or on ranks 2 and 3. Will be excluded from the mobility area
Bitboard blockedPawns[] = {
pos.pieces(WHITE, PAWN) & (shift_bb<DELTA_S>(pos.pieces()) | Rank2BB | Rank3BB),
pos.pieces(BLACK, PAWN) & (shift_bb<DELTA_N>(pos.pieces()) | Rank7BB | Rank6BB)
};
// Do not include in mobility squares protected by enemy pawns, or occupied
// by our blocked pawns or king.
Bitboard mobilityArea[] = {
~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.king_square(WHITE)),
~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.king_square(BLACK))
};
// Evaluate pieces and mobility
score += evaluate_pieces<KNIGHT, WHITE, Trace>(pos, ei, mobility, mobilityArea);