🧬 Move ordering: MVV-LVA + caphist -> MVV + caphist SPSA'ed high level

src/Lynx/Configuration.cs

@@ -55,7 +55,7 @@ public sealed class GeneralSettings
 {
     public bool EnableLogging { get; set; }
 
-    public bool EnableTuning { get; set; }
+    public bool EnableTuning { get; set; } = true;
 }
 
 public sealed class EngineSettings
@@ -236,6 +236,21 @@ public int Threads
     public int HistoryPrunning_Margin { get; set; } = -1940;
 
     #endregion
+
+    [SPSA<int>(0, 1000, 100)]
+    public int MVV_Pawn { get; set; } = 63;
+
+    [SPSA<int>(2500, 3500, 100)]
+    public int MVV_Knight { get; set; } = 2958;
+
+    [SPSA<int>(2500, 3500, 100)]
+    public int MVV_Bishop { get; set; } = 2938;
+
+    [SPSA<int>(5000, 6500, 100)]
+    public int MVV_Rook { get; set; } = 5865;
+
+    [SPSA<int>(9000, 10500, 100)]
+    public int MVV_Queen { get; set; } = 9644;
 }
 
 [JsonSourceGenerationOptions(

src/Lynx/EvaluationConstants.cs

@@ -79,10 +79,10 @@ static EvaluationConstants()
         /* k */ [1000, 3500, 4001, 5000, 11000, 0,     0,    0,    0,    0,     0 ], // 0]
     ];
 
-    public static ReadOnlySpan<int> MVV_PieceValues =>
+    public static readonly int[] MVV_PieceValues =
     [
-        1000, 3500, 4000, 5000, 11000, 0,
-        1000, 3500, 4000, 5000, 11000, 0,
+        Configuration.EngineSettings.MVV_Pawn, Configuration.EngineSettings.MVV_Knight, Configuration.EngineSettings.MVV_Bishop, Configuration.EngineSettings.MVV_Rook, Configuration.EngineSettings.MVV_Queen, 0,
+        Configuration.EngineSettings.MVV_Pawn, Configuration.EngineSettings.MVV_Knight, Configuration.EngineSettings.MVV_Bishop, Configuration.EngineSettings.MVV_Rook, Configuration.EngineSettings.MVV_Queen, 0,
         0
     ];
 

src/Lynx/Search/MoveOrdering.cs

@@ -8,7 +8,7 @@ namespace Lynx;
 public sealed partial class Engine
 {
     /// <summary>
-    /// Returns the score evaluation of a move taking into account <paramref name="bestMoveTTCandidate"/>, <see cref="MostValueableVictimLeastValuableAttacker"/>, <see cref="_killerMoves"/> and <see cref="_quietHistory"/>
+    /// Returns the score evaluation of a move taking into account <paramref name="bestMoveTTCandidate"/>, <see cref="MVV_PieceValues"/>, <see cref="_killerMoves"/> and <see cref="_quietHistory"/>
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal int ScoreMove(Move move, int ply, bool isNotQSearch, ShortMove bestMoveTTCandidate = default)
@@ -48,8 +48,7 @@ internal int ScoreMove(Move move, int ply, bool isNotQSearch, ShortMove bestMove
             Debug.Assert(capturedPiece != (int)Piece.K && capturedPiece != (int)Piece.k, $"{move.UCIString()} capturing king is generated in position {Game.CurrentPosition.FEN()}");
 
             return baseCaptureScore
-                + MostValueableVictimLeastValuableAttacker[piece][capturedPiece]
-                //+ EvaluationConstants.MVV_PieceValues[capturedPiece]
+                + MVV_PieceValues[capturedPiece]
                 + _captureHistory[CaptureHistoryIndex(piece, move.TargetSquare(), capturedPiece)];
         }
 

src/Lynx/UCIHandler.cs

@@ -559,6 +559,47 @@ private void HandleSetOption(ReadOnlySpan<char> command)
                     break;
                 }
 
+            case "mvv_pawn":
+                {
+                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
+                    {
+                        Configuration.EngineSettings.MVV_Pawn = value;
+                    }
+                    break;
+                }
+            case "mvv_knight":
+                {
+                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
+                    {
+                        Configuration.EngineSettings.MVV_Knight = value;
+                    }
+                    break;
+                }
+            case "mvv_bishop":
+                {
+                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
+                    {
+                        Configuration.EngineSettings.MVV_Bishop = value;
+                    }
+                    break;
+                }
+            case "mvv_rook":
+                {
+                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
+                    {
+                        Configuration.EngineSettings.MVV_Rook = value;
+                    }
+                    break;
+                }
+            case "mvv_queen":
+                {
+                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
+                    {
+                        Configuration.EngineSettings.MVV_Queen = value;
+                    }
+                    break;
+                }
+
             #endregion
 
             default:

tests/Lynx.Test/Model/MoveScoreTest.cs

@@ -16,7 +16,7 @@ public class MoveScoreTest : BaseTest
     /// 2   P P P B B P P P
     /// 1   R . . . K . . R
     ///     a b c d e f g h
-    /// This tests indirectly <see cref="EvaluationConstants.MostValueableVictimLeastValuableAttacker"/>
+    /// This tests indirectly <see cref="EvaluationConstants.MostValueableVictimLeastValuableAttacker"/> and <see cref="MVV_PieceValues"/>
     /// </summary>
     [TestCase(Constants.TrickyTestPositionFEN)]
     public void MoveScore(string fen)
@@ -61,6 +61,6 @@ public void MoveScoreEnPassant(string fen, string moveWithHighestScore)
         var allMoves = MoveGenerator.GenerateAllMoves(engine.Game.CurrentPosition).OrderByDescending(move => engine.ScoreMove(move, default, default)).ToList();
 
         Assert.AreEqual(moveWithHighestScore, allMoves[0].UCIString());
-        Assert.AreEqual(EvaluationConstants.GoodCaptureMoveBaseScoreValue + EvaluationConstants.MostValueableVictimLeastValuableAttacker[0][6], engine.ScoreMove(allMoves[0], default, default));
+        Assert.AreEqual(EvaluationConstants.GoodCaptureMoveBaseScoreValue + EvaluationConstants.MVV_PieceValues[0], engine.ScoreMove(allMoves[0], default, default));
     }
 }