HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-21 09:37:16 +08:00
Code Issues Packages Projects Releases Wiki Activity

Bonus for restricting opponent's piece moves

Browse Source 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 51883 W: 11297 L: 10915 D: 29671
http://tests.stockfishchess.org/tests/view/5bf1e2ee0ebc595e0ae3cacd

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 15859 W: 2752 L: 2565 D: 10542
http://tests.stockfishchess.org/tests/view/5bf337980ebc5902bcecbf62

Notes:

(1) The bonus value has not been carefully tested, so it may be possible
to find slightly better values.

(2) Plan is to now try adding similar restriction for pawns. I wanted to
include that as part of this pull request, but I was advised to do it as
two separate pull requests. STC is currently running here, but may not add
enough value to pass green.

Bench: 3679086
This commit is contained in:
xoto10
2018-11-20 07:45:00 +01:00
committed by Stéphane Nicolet
parent cf5d683408
commit 3925750945
3 changed files with 13 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/evaluate.cpp
View File

@@ -162,6 +162,7 @@ namespace {
constexpr Score MinorBehindPawn = S( 16, 0); constexpr Score MinorBehindPawn = S( 16, 0);
constexpr Score Overload = S( 12, 6); constexpr Score Overload = S( 12, 6);
constexpr Score PawnlessFlank = S( 18, 94); constexpr Score PawnlessFlank = S( 18, 94);
constexpr Score RestrictedPiece = S( 7, 6);
constexpr Score RookOnPawn = S( 10, 28); constexpr Score RookOnPawn = S( 10, 28);
constexpr Score SliderOnQueen = S( 49, 21); constexpr Score SliderOnQueen = S( 49, 21);
constexpr Score ThreatByKing = S( 21, 84); constexpr Score ThreatByKing = S( 21, 84);
@@ -508,7 +509,7 @@ namespace {
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH); constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe; Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe, restricted;
Score score = SCORE_ZERO; Score score = SCORE_ZERO;
// Non-pawn enemies // Non-pawn enemies
@@ -558,6 +559,13 @@ namespace {
score += Overload * popcount(b); score += Overload * popcount(b);
} }
// Bonus for restricting their piece moves
restricted = attackedBy[Them][ALL_PIECES]
& ~attackedBy[Them][PAWN]
& ~attackedBy2[Them]
& attackedBy[Us][ALL_PIECES];
score += RestrictedPiece * popcount(restricted);
// Bonus for enemy unopposed weak pawns // Bonus for enemy unopposed weak pawns
if (pos.pieces(Us, ROOK, QUEEN)) if (pos.pieces(Us, ROOK, QUEEN))
score += WeakUnopposedPawn * pe->weak_unopposed(Them); score += WeakUnopposedPawn * pe->weak_unopposed(Them);

2
src/pawns.cpp
View File

@@ -221,7 +221,7 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
int d = std::min(f, ~f); int d = std::min(f, ~f);
safety += ShelterStrength[d][ourRank]; safety += ShelterStrength[d][ourRank];
safety -= (ourRank && (ourRank == theirRank - 1)) ? 66 * (theirRank == RANK_3) safety -= (ourRank && (ourRank == theirRank - 1)) ? 66 * (theirRank == RANK_3)
: UnblockedStorm[d][theirRank]; : UnblockedStorm[d][theirRank];
} }

6
src/search.cpp
View File

@@ -85,10 +85,10 @@ namespace {
return d > 17 ? 0 : 29 * d * d + 138 * d - 134; return d > 17 ? 0 : 29 * d * d + 138 * d - 134;
} }
// Add a small random component to draw evaluations to keep search dynamic // Add a small random component to draw evaluations to keep search dynamic
// and to avoid 3fold-blindness. // and to avoid 3fold-blindness.
Value value_draw(Depth depth, Thread* thisThread) { Value value_draw(Depth depth, Thread* thisThread) {
return depth < 4 ? VALUE_DRAW return depth < 4 ? VALUE_DRAW
: VALUE_DRAW + Value(2 * (thisThread->nodes.load(std::memory_order_relaxed) % 2) - 1); : VALUE_DRAW + Value(2 * (thisThread->nodes.load(std::memory_order_relaxed) % 2) - 1);
} }
@@ -599,7 +599,7 @@ namespace {
if ( Threads.stop.load(std::memory_order_relaxed) if ( Threads.stop.load(std::memory_order_relaxed)
|| pos.is_draw(ss->ply) || pos.is_draw(ss->ply)
|| ss->ply >= MAX_PLY) || ss->ply >= MAX_PLY)
return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos)
: value_draw(depth, pos.this_thread()); : value_draw(depth, pos.this_thread());
// Step 3. Mate distance pruning. Even if we mate at the next move our score // Step 3. Mate distance pruning. Even if we mate at the next move our score