Bench: 23428536

TerjeKir · Dec 4, 2023 · 8954879 · 8954879
1 parent 1fa36a9
commit 8954879
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Showing 3 changed files with 47 additions and 1 deletion.
diff --git a/src/evaluate.c b/src/evaluate.c
@@ -107,6 +107,13 @@ const int ThreatByRook[8] = {
     S(-17, 47), S( 93,-73), S(  0,  0), S(  0,  0)
 };
 
+const int Imbalance[4][4] = {
+    { S(  0, 14) },
+    { S( -3, 12), S(  6,-17) },
+    { S( -9, 14), S(-15,-17), S(-17,-25) },
+    { S(-16, 42), S(-30, 46), S(-32, 72), S(-151,184) }
+};
+
 // KingLineDanger
 const int KingLineDanger[28] = {
     S(  0,  0), S(  0,  0), S( 15,  0), S( 11, 21),
@@ -468,6 +475,19 @@ INLINE int EvalThreats(const Position *pos, const EvalInfo *ei, const Color colo
     return eval;
 }
 
+INLINE int EvalImbalance(const Position *pos, Color color) {
+    int eval = 0;
+
+    for (int us = KNIGHT; us < KING; us++)
+        for (int them = PAWN; them < us; them++) {
+            int count = PopCount(colorPieceBB(color, us)) * PopCount(colorPieceBB(!color, them));
+            eval += Imbalance[us-2][them-1] * count;
+            TraceCount(Imbalance[us-2][them-1]);
+        }
+
+    return eval;
+}
+
 // Initializes the eval info struct
 INLINE void InitEvalInfo(const Position *pos, EvalInfo *ei, const Color color) {
 
@@ -550,6 +570,10 @@ int EvalPosition(const Position *pos, PawnCache pc) {
     eval +=  EvalThreats(pos, &ei, WHITE)
            - EvalThreats(pos, &ei, BLACK);
 
+    // Evaluate piece imbalance
+    eval +=  EvalImbalance(pos, WHITE)
+           - EvalImbalance(pos, BLACK);
+
     TraceEval(eval);
 
     // Adjust eval by scale factor

diff --git a/src/tuner/tuner.c b/src/tuner/tuner.c
@@ -74,6 +74,9 @@ extern const int PawnPhalanx[RANK_NB];
 extern const int ThreatByMinor[8];
 extern const int ThreatByRook[8];
 
+
+extern const int Imbalance[4][4];
+
 // KingLineDanger
 extern const int KingLineDanger[28];
 
@@ -201,6 +204,12 @@ static void InitBaseParams(TVector tparams) {
     InitBaseArray(ThreatByMinor, 8);
     InitBaseArray(ThreatByRook, 8);
 
+
+    InitBaseArray(Imbalance[KNIGHT-2], 1);
+    InitBaseArray(Imbalance[BISHOP-2], 2);
+    InitBaseArray(Imbalance[  ROOK-2], 3);
+    InitBaseArray(Imbalance[ QUEEN-2], 4);
+
     // KingLineDanger
     InitBaseArray(KingLineDanger, 28);
 
@@ -273,6 +282,12 @@ static void PrintParameters(TVector updates, TVector base) {
     PrintArray(ThreatByMinor, 8);
     PrintArray(ThreatByRook, 8);
 
+
+    PrintArray(Imbalance[KNIGHT-2], 1);
+    PrintArray(Imbalance[BISHOP-2], 2);
+    PrintArray(Imbalance[  ROOK-2], 3);
+    PrintArray(Imbalance[ QUEEN-2], 4);
+
     puts("\n// KingLineDanger");
     PrintArray(KingLineDanger, 28);
 
@@ -340,6 +355,12 @@ static void InitCoefficients(TCoeffs coeffs) {
     InitCoeffArray(ThreatByMinor, 8);
     InitCoeffArray(ThreatByRook, 8);
 
+
+    InitCoeffArray(Imbalance[KNIGHT-2], 1);
+    InitCoeffArray(Imbalance[BISHOP-2], 2);
+    InitCoeffArray(Imbalance[  ROOK-2], 3);
+    InitCoeffArray(Imbalance[ QUEEN-2], 4);
+
     // KingLineDanger
     InitCoeffArray(KingLineDanger, 28);
 

diff --git a/src/tuner/tuner.h b/src/tuner/tuner.h
@@ -49,7 +49,7 @@
 // #define NPOSITIONS   (14669229) // Total FENS in the book
 
 
-#define NTERMS       (     552) // Number of terms being tuned
+#define NTERMS       (     562) // Number of terms being tuned
 #define MAXEPOCHS    (   10000) // Max number of epochs allowed
 #define REPORTING    (      50) // How often to print the new parameters
 #define NPARTITIONS  (      64) // Total thread partitions
@@ -97,6 +97,7 @@ typedef struct EvalTrace {
     int PawnPhalanx[RANK_NB][COLOR_NB];
     int ThreatByMinor[8][COLOR_NB];
     int ThreatByRook[8][COLOR_NB];
+    int Imbalance[4][4][COLOR_NB];
     int KingLineDanger[28][COLOR_NB];
     int Mobility[4][28][COLOR_NB];