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🦈 IMP: Move Iteration respecting History Bonus #11

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merged 4 commits into from
Jun 6, 2023
Merged

🦈 IMP: Move Iteration respecting History Bonus #11

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e194f50
Increase history alteration during search based on a combination of m…
TheBlackPlague Jun 3, 2023
2058a57
Remove the accidentally added change.
TheBlackPlague Jun 3, 2023
2058265
Merge branch 'master' into history-move-iteration-dependent
TheBlackPlague Jun 5, 2023
881d66e
It should've been std::max instead of std::min.
TheBlackPlague Jun 5, 2023
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19 changes: 11 additions & 8 deletions src/Engine/Search.h
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Original file line number Diff line number Diff line change
Expand Up @@ -304,14 +304,15 @@ namespace StockDory
//endregion

//region Fail-soft Alpha Beta Negamax
int32_t bestEvaluation = -Infinity;
Move bestMove = NoMove;
EngineEntryType ttEntryType = AlphaUnchanged;
int32_t bestEvaluation = -Infinity;
Move bestMove = NoMove;
EngineEntryType ttEntryType = AlphaUnchanged;

const uint8_t lmpQuietThreshold = LMPQuietThresholdBase + depth * depth;
const bool lmp = !Root && !checked && depth <= LMPDepthThreshold;
const bool lmr = depth >= LMRDepthThreshold && !checked;
const int32_t historyBonus = depth * depth;
const bool lmp = !Root && !checked && depth <= LMPDepthThreshold;
const bool lmr = depth >= LMRDepthThreshold && !checked;
const int32_t historyBonus = depth * depth;
const uint8_t historyFactor = std::max(depth / 3, 1);

uint8_t quietMoveCount = 0;
for (uint8_t i = 0; i < moves.Count(); i++) {
Expand Down Expand Up @@ -385,11 +386,13 @@ namespace StockDory
KTable.Set<1>(ply, move);
}

HTable.Get(Board[move.From()].Piece(), Color, move.To()) += historyBonus;
HTable.Get(Board[move.From()].Piece(), Color, move.To())
+= historyBonus + i * historyFactor;

for (uint8_t q = 1; q < quietMoveCount; q++) {
const Move other = moves.UnsortedAccess(i - q);
HTable.Get(Board[other.From()].Piece(), Color, other.To()) -= historyBonus;
HTable.Get(Board[other.From()].Piece(), Color, other.To())
-= historyBonus + (quietMoveCount - q) * historyFactor;
}
}

Expand Down