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Search + Eval + Movepick Tune
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Passed STC:
https://tests.stockfishchess.org/tests/view/65ef15220ec64f0526c44b04
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 24480 W: 6459 L: 6153 D: 11868
Ptnml(0-2): 101, 2798, 6184, 3008, 149

Passed LTC:
https://tests.stockfishchess.org/tests/view/65ef4bac0ec64f0526c44f50
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 53316 W: 13561 L: 13203 D: 26552
Ptnml(0-2): 27, 5925, 14408, 6259, 39

closes #5104

Bench: 1715522
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@FauziAkram @Disservin
FauziAkram authored and Disservin committed Mar 12, 2024
1 parent daa3ef9 commit 627974c
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Showing 5 changed files with 27 additions and 27 deletions.
8 changes: 4 additions & 4 deletions src/evaluate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -59,15 +59,15 @@ Value Eval::evaluate(const Eval::NNUE::Networks& networks, const Position& pos,
: networks.big.evaluate(pos, true, &nnueComplexity, false);

// Blend optimism and eval with nnue complexity and material imbalance
optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 512;
nnue -= nnue * (nnueComplexity + std::abs(simpleEval - nnue)) / 32768;
optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 524;
nnue -= nnue * (nnueComplexity + std::abs(simpleEval - nnue)) / 31950;

int npm = pos.non_pawn_material() / 64;
int v = (nnue * (915 + npm + 9 * pos.count<PAWN>()) + optimism * (154 + npm)) / 1024;
int v = (nnue * (927 + npm + 9 * pos.count<PAWN>()) + optimism * (159 + npm)) / 1000;

// Damp down the evaluation linearly when shuffling
int shuffling = pos.rule50_count();
v = v * (200 - shuffling) / 214;
v = v * (195 - shuffling) / 228;

// Guarantee evaluation does not hit the tablebase range
v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
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2 changes: 1 addition & 1 deletion src/evaluate.h
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Expand Up @@ -29,7 +29,7 @@ class Position;

namespace Eval {

constexpr inline int SmallNetThreshold = 1139, PsqtOnlyThreshold = 2500;
constexpr inline int SmallNetThreshold = 1136, PsqtOnlyThreshold = 2656;

// The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
// for the build process (profile-build and fishtest) to work. Do not change the
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16 changes: 8 additions & 8 deletions src/movepick.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -190,18 +190,18 @@ void MovePicker::score() {
m.value += bool(pos.check_squares(pt) & to) * 16384;

// bonus for escaping from capture
m.value += threatenedPieces & from ? (pt == QUEEN && !(to & threatenedByRook) ? 50000
: pt == ROOK && !(to & threatenedByMinor) ? 25000
: !(to & threatenedByPawn) ? 15000
m.value += threatenedPieces & from ? (pt == QUEEN && !(to & threatenedByRook) ? 51000
: pt == ROOK && !(to & threatenedByMinor) ? 24950
: !(to & threatenedByPawn) ? 14450
: 0)
: 0;

// malus for putting piece en prise
m.value -= !(threatenedPieces & from)
? (pt == QUEEN ? bool(to & threatenedByRook) * 50000
+ bool(to & threatenedByMinor) * 10000
: pt == ROOK ? bool(to & threatenedByMinor) * 25000
: pt != PAWN ? bool(to & threatenedByPawn) * 15000
? (pt == QUEEN ? bool(to & threatenedByRook) * 48150
+ bool(to & threatenedByMinor) * 10650
: pt == ROOK ? bool(to & threatenedByMinor) * 24500
: pt != PAWN ? bool(to & threatenedByPawn) * 14950
: 0)
: 0;
}
Expand Down Expand Up @@ -241,7 +241,7 @@ Move MovePicker::select(Pred filter) {
// moves left, picking the move with the highest score from a list of generated moves.
Move MovePicker::next_move(bool skipQuiets) {

auto quiet_threshold = [](Depth d) { return -3330 * d; };
auto quiet_threshold = [](Depth d) { return -3550 * d; };

top:
switch (stage)
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24 changes: 12 additions & 12 deletions src/search.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,8 +55,8 @@ namespace {

// Futility margin
Value futility_margin(Depth d, bool noTtCutNode, bool improving, bool oppWorsening) {
Value futilityMult = 121 - 43 * noTtCutNode;
Value improvingDeduction = 3 * improving * futilityMult / 2;
Value futilityMult = 122 - 46 * noTtCutNode;
Value improvingDeduction = 57 * improving * futilityMult / 32;
Value worseningDeduction = (331 + 45 * improving) * oppWorsening * futilityMult / 1024;

return futilityMult * d - improvingDeduction - worseningDeduction;
Expand All @@ -69,15 +69,15 @@ constexpr int futility_move_count(bool improving, Depth depth) {
// Add correctionHistory value to raw staticEval and guarantee evaluation does not hit the tablebase range
Value to_corrected_static_eval(Value v, const Worker& w, const Position& pos) {
auto cv = w.correctionHistory[pos.side_to_move()][pawn_structure_index<Correction>(pos)];
v += cv * std::abs(cv) / 10759;
v += cv * std::abs(cv) / 11450;
return std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
}

// History and stats update bonus, based on depth
int stat_bonus(Depth d) { return std::min(249 * d - 327, 1192); }

// History and stats update malus, based on depth
int stat_malus(Depth d) { return std::min(516 * d - 299, 1432); }
int stat_malus(Depth d) { return std::min(516 * d - 299, 1254); }

// Add a small random component to draw evaluations to avoid 3-fold blindness
Value value_draw(size_t nodes) { return VALUE_DRAW - 1 + Value(nodes & 0x2); }
Expand Down Expand Up @@ -301,12 +301,12 @@ void Search::Worker::iterative_deepening() {

// Reset aspiration window starting size
Value avg = rootMoves[pvIdx].averageScore;
delta = 9 + avg * avg / 12804;
delta = 9 + avg * avg / 12800;
alpha = std::max(avg - delta, -VALUE_INFINITE);
beta = std::min(avg + delta, VALUE_INFINITE);

// Adjust optimism based on root move's averageScore (~4 Elo)
optimism[us] = 131 * avg / (std::abs(avg) + 90);
optimism[us] = 130 * avg / (std::abs(avg) + 90);
optimism[~us] = -optimism[us];

// Start with a small aspiration window and, in the case of a fail
Expand Down Expand Up @@ -500,7 +500,7 @@ void Search::Worker::clear() {
h->fill(-71);

for (size_t i = 1; i < reductions.size(); ++i)
reductions[i] = int((19.02 + std::log(size_t(options["Threads"])) / 2) * std::log(i));
reductions[i] = int((19.80 + std::log(size_t(options["Threads"])) / 2) * std::log(i));
}


Expand Down Expand Up @@ -732,12 +732,12 @@ Value Search::Worker::search(
// Use static evaluation difference to improve quiet move ordering (~9 Elo)
if (((ss - 1)->currentMove).is_ok() && !(ss - 1)->inCheck && !priorCapture)
{
int bonus = std::clamp(-14 * int((ss - 1)->staticEval + ss->staticEval), -1621, 1237);
int bonus = std::clamp(-14 * int((ss - 1)->staticEval + ss->staticEval), -1621, 1238);
bonus = bonus > 0 ? 2 * bonus : bonus / 2;
thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] << bonus;
if (type_of(pos.piece_on(prevSq)) != PAWN && ((ss - 1)->currentMove).type_of() != PROMOTION)
thisThread->pawnHistory[pawn_structure_index(pos)][pos.piece_on(prevSq)][prevSq]
<< bonus / 4;
<< bonus / 2;
}

// Set up the improving flag, which is true if current static evaluation is
Expand Down Expand Up @@ -828,7 +828,7 @@ Value Search::Worker::search(
// Step 11. ProbCut (~10 Elo)
// If we have a good enough capture (or queen promotion) and a reduced search returns a value
// much above beta, we can (almost) safely prune the previous move.
probCutBeta = beta + 164 - 62 * improving;
probCutBeta = beta + 168 - 64 * improving;
if (
!PvNode && depth > 3
&& std::abs(beta) < VALUE_TB_WIN_IN_MAX_PLY
Expand Down Expand Up @@ -1139,7 +1139,7 @@ Value Search::Worker::search(
+ (*contHist[3])[movedPiece][move.to_sq()] - 4587;

// Decrease/increase reduction for moves with a good/bad history (~8 Elo)
r -= ss->statScore / 12372;
r -= ss->statScore / 14956;

// Step 17. Late moves reduction / extension (LMR, ~117 Elo)
if (depth >= 2 && moveCount > 1 + rootNode)
Expand Down Expand Up @@ -1627,7 +1627,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,

Depth Search::Worker::reduction(bool i, Depth d, int mn, int delta) {
int reductionScale = reductions[d] * reductions[mn];
return (reductionScale + 1091 - delta * 759 / rootDelta) / 1024 + (!i && reductionScale > 952);
return (reductionScale + 1091 - delta * 759 / rootDelta) / 1024 + (!i && reductionScale > 950);
}

namespace {
Expand Down
4 changes: 2 additions & 2 deletions src/tt.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -134,8 +134,8 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
// Find an entry to be replaced according to the replacement strategy
TTEntry* replace = tte;
for (int i = 1; i < ClusterSize; ++i)
if (replace->depth8 - replace->relative_age(generation8)
> tte[i].depth8 - tte[i].relative_age(generation8))
if (replace->depth8 - replace->relative_age(generation8) * 2
> tte[i].depth8 - tte[i].relative_age(generation8) * 2)
replace = &tte[i];

return found = false, replace;
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