Remove old razoring implementation

lynx-chess · May 17, 2024 · e03e933 · e03e933
1 parent 19b2ee9
commit e03e933
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Showing 5 changed files with 0 additions and 84 deletions.
diff --git a/src/Lynx.Cli/appsettings.json b/src/Lynx.Cli/appsettings.json
@@ -38,10 +38,6 @@
     "RFP_MaxDepth": 6,
     "RFP_DepthScalingFactor": 107,
 
-    "Razoring_MaxDepth": 2,
-    "Razoring_Depth1Bonus": 84,
-    "Razoring_NotDepth1Bonus": 135,
-
     "IIR_MinDepth": 3,
 
     "LMP_MaxDepth": 6,

diff --git a/src/Lynx/Configuration.cs b/src/Lynx/Configuration.cs
@@ -161,15 +161,6 @@ public sealed class EngineSettings
     [SPSAAttribute<int>(1, 300, 10)]
     public int RFP_DepthScalingFactor { get; set; } = 107;
 
-    [SPSAAttribute<int>(1, 10, 1)]
-    public int Razoring_MaxDepth { get; set; } = 2;
-
-    [SPSAAttribute<int>(1, 300, 10)]
-    public int Razoring_Depth1Bonus { get; set; } = 84;
-
-    [SPSAAttribute<int>(1, 300, 10)]
-    public int Razoring_NotDepth1Bonus { get; set; } = 135;
-
     [SPSAAttribute<int>(1, 10, 1)]
     public int IIR_MinDepth { get; set; } = 3;
 

diff --git a/src/Lynx/Search/NegaMax.cs b/src/Lynx/Search/NegaMax.cs
@@ -107,37 +107,6 @@ private int NegaMax(int depth, int ply, int alpha, int beta, bool parentWasNullM
                     return (staticEval + beta) / 2;
 #pragma warning restore S3949 // Calculations should not overflow
                 }
-
-                // 🔍 Razoring - Strelka impl (CPW) - https://www.chessprogramming.org/Razoring#Strelka
-                if (depth <= Configuration.EngineSettings.Razoring_MaxDepth)
-                {
-                    var score = staticEval + Configuration.EngineSettings.Razoring_Depth1Bonus;
-
-                    if (score < beta)               // Static evaluation + bonus indicates fail-low node
-                    {
-                        if (depth == 1)
-                        {
-                            var qSearchScore = QuiescenceSearch(ply, alpha, beta);
-
-                            return qSearchScore > score
-                                ? qSearchScore
-                                : score;
-                        }
-
-                        score += Configuration.EngineSettings.Razoring_NotDepth1Bonus;
-
-                        if (score < beta)               // Static evaluation indicates fail-low node
-                        {
-                            var qSearchScore = QuiescenceSearch(ply, alpha, beta);
-                            if (qSearchScore < beta)    // Quiescence score also indicates fail-low node
-                            {
-                                return qSearchScore > score
-                                    ? qSearchScore
-                                    : score;
-                            }
-                        }
-                    }
-                }
             }
 
             // 🔍 Null Move Pruning (NMP) - our position is so good that we can potentially afford giving our opponent a double move and still remain ahead of beta

diff --git a/src/Lynx/UCIHandler.cs b/src/Lynx/UCIHandler.cs
@@ -366,31 +366,6 @@ private void HandleSetOption(ReadOnlySpan<char> command)
                     break;
                 }
 
-            case "razoring_maxdepth":
-                {
-                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
-                    {
-                        Configuration.EngineSettings.Razoring_MaxDepth = value;
-                    }
-                    break;
-                }
-            case "razoring_depth1bonus":
-                {
-                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
-                    {
-                        Configuration.EngineSettings.Razoring_Depth1Bonus = value;
-                    }
-                    break;
-                }
-            case "razoring_notdepth1bonus":
-                {
-                    if (length > 4 && int.TryParse(command[commandItems[4]], out var value))
-                    {
-                        Configuration.EngineSettings.Razoring_NotDepth1Bonus = value;
-                    }
-                    break;
-                }
-
             case "iir_mindepth":
                 {
                     if (length > 4 && int.TryParse(command[commandItems[4]], out var value))

diff --git a/tests/Lynx.Test/ConfigurationValuesTest.cs b/tests/Lynx.Test/ConfigurationValuesTest.cs
@@ -11,19 +11,4 @@ namespace Lynx.Test;
 [NonParallelizable]
 public class ConfigurationValuesTest
 {
-    [Test]
-    public void RazoringValues()
-    {
-        Assert.Greater(Configuration.EngineSettings.RFP_MaxDepth, Configuration.EngineSettings.Razoring_MaxDepth);
-
-        var config = new ConfigurationBuilder()
-            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: false)
-            .Build();
-
-        var engineSettingsSection = config.GetRequiredSection(nameof(EngineSettings));
-        Assert.IsNotNull(engineSettingsSection);
-        engineSettingsSection.Bind(Configuration.EngineSettings);
-
-        Assert.Greater(Configuration.EngineSettings.RFP_MaxDepth, Configuration.EngineSettings.Razoring_MaxDepth);
-    }
 }