Remove passed pawns

lynx-chess · May 16, 2024 · 638e715 · 638e715
1 parent 3f075ee
commit 638e715
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Showing 3 changed files with 28 additions and 62 deletions.
diff --git a/src/Lynx.Cli/appsettings.json b/src/Lynx.Cli/appsettings.json
@@ -58,10 +58,10 @@
     "FP_Margin": 250,
 
     // Evaluation
-    //"DoubledPawnPenalty": {
-    //  "MG": -6,
-    //  "EG": -12
-    //},
+    "DoubledPawnPenalty": {
+      "MG": -6,
+      "EG": -12
+    },
     "IsolatedPawnPenalty": {
       "MG": -17,
       "EG": -13
@@ -101,40 +101,6 @@
     "BishopPairBonus": {
       "MG": 31,
       "EG": 80
-    },
-    "PassedPawnBonus": {
-      "Rank0": {
-        "MG": 0,
-        "EG": 0
-      },
-      "Rank1": {
-        "MG": -2,
-        "EG": 7
-      },
-      "Rank2": {
-        "MG": -15,
-        "EG": 13
-      },
-      "Rank3": {
-        "MG": -14,
-        "EG": 41
-      },
-      "Rank4": {
-        "MG": 20,
-        "EG": 74
-      },
-      "Rank5": {
-        "MG": 60,
-        "EG": 150
-      },
-      "Rank6": {
-        "MG": 98,
-        "EG": 217
-      },
-      "Rank7": {
-        "MG": 0,
-        "EG": 0
-      }
     }
     // End of evaluation
   },

diff --git a/src/Lynx/Configuration.cs b/src/Lynx/Configuration.cs
@@ -203,7 +203,7 @@ public sealed class EngineSettings
 
     #region Evaluation
 
-    //public TaperedEvaluationTerm DoubledPawnPenalty { get; set; } = new(-6, -12);
+    public TaperedEvaluationTerm DoubledPawnPenalty { get; set; } = new(-6, -12);
 
     public TaperedEvaluationTerm IsolatedPawnPenalty { get; set; } = new(-17, -13);
 
@@ -225,15 +225,15 @@ public sealed class EngineSettings
 
     public TaperedEvaluationTerm BishopPairBonus { get; set; } = new(31, 80);
 
-    public TaperedEvaluationTermByRank PassedPawnBonus { get; set; } = new(
-        new(0, 0),
-        new(-2, 7),
-        new(-15, 13),
-        new(-14, 41),
-        new(20, 74),
-        new(60, 150),
-        new(98, 217),
-        new(0, 0));
+    //public TaperedEvaluationTermByRank PassedPawnBonus { get; set; } = new(
+    //    new(0, 0),
+    //    new(-2, 7),
+    //    new(-15, 13),
+    //    new(-14, 41),
+    //    new(20, 74),
+    //    new(60, 150),
+    //    new(98, 217),
+    //    new(0, 0));
 
     #endregion
 }

diff --git a/src/Lynx/Model/Position.cs b/src/Lynx/Model/Position.cs
@@ -867,26 +867,26 @@ private int PawnAdditionalEvaluation(int squareIndex, int pieceIndex)
     {
         int packedBonus = 0;
 
-        //var doublePawnsCount = (PieceBitBoards[pieceIndex] & Masks.FileMasks[squareIndex]).CountBits();
-        //if (doublePawnsCount > 1)
-        //{
-        //    packedBonus += doublePawnsCount * Configuration.EngineSettings.DoubledPawnPenalty.PackedEvaluation;
-        //}
+        var doublePawnsCount = (PieceBitBoards[pieceIndex] & Masks.FileMasks[squareIndex]).CountBits();
+        if (doublePawnsCount > 1)
+        {
+            packedBonus += doublePawnsCount * Configuration.EngineSettings.DoubledPawnPenalty.PackedEvaluation;
+        }
 
         if ((PieceBitBoards[pieceIndex] & Masks.IsolatedPawnMasks[squareIndex]) == default) // isIsolatedPawn
         {
             packedBonus += Configuration.EngineSettings.IsolatedPawnPenalty.PackedEvaluation;
         }
 
-        if ((PieceBitBoards[(int)Piece.p - pieceIndex] & Masks.PassedPawns[pieceIndex][squareIndex]) == default)    // isPassedPawn
-        {
-            var rank = Constants.Rank[squareIndex];
-            if (pieceIndex == (int)Piece.p)
-            {
-                rank = 7 - rank;
-            }
-            packedBonus += Configuration.EngineSettings.PassedPawnBonus[rank].PackedEvaluation;
-        }
+        //if ((PieceBitBoards[(int)Piece.p - pieceIndex] & Masks.PassedPawns[pieceIndex][squareIndex]) == default)    // isPassedPawn
+        //{
+        //    var rank = Constants.Rank[squareIndex];
+        //    if (pieceIndex == (int)Piece.p)
+        //    {
+        //        rank = 7 - rank;
+        //    }
+        //    packedBonus += Configuration.EngineSettings.PassedPawnBonus[rank].PackedEvaluation;
+        //}
 
         return packedBonus;
     }