From d40486a6c40b8fede3754b595a6eb203ff157cf6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eduardo=20C=C3=A1ceres?=
 <eduardo.caceresdelacalle@gmail.com>
Date: Wed, 22 Nov 2023 04:16:39 +0100
Subject: [PATCH] Count all moves

---
 src/Lynx.Cli/appsettings.json |  5 +++--
 src/Lynx/Configuration.cs     |  6 ++++--
 src/Lynx/Search/NegaMax.cs    | 14 +++++++-------
 3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/Lynx.Cli/appsettings.json b/src/Lynx.Cli/appsettings.json
index 4220df5db..d0fa15d5f 100644
--- a/src/Lynx.Cli/appsettings.json
+++ b/src/Lynx.Cli/appsettings.json
@@ -38,8 +38,9 @@
 
     "IIR_MinDepth": 4,
 
-    "LMP_MaxDepth": 3,
-    "LMP_BaseMovesToTry": 3,
+    "LMP_MaxDepth": 2,
+    "LMP_BaseMovesToTry": 0,
+    "LMP_MovesDepthMultiplier": 10,
 
     "History_MaxMoveValue": 8192,
 
diff --git a/src/Lynx/Configuration.cs b/src/Lynx/Configuration.cs
index 972d1438a..12903dff0 100644
--- a/src/Lynx/Configuration.cs
+++ b/src/Lynx/Configuration.cs
@@ -149,9 +149,11 @@ public sealed class EngineSettings
 
     public int IIR_MinDepth { get; set; } = 4;
 
-    public int LMP_MaxDepth { get; set; } = 3;
+    public int LMP_MaxDepth { get; set; } = 2;
 
-    public int LMP_BaseMovesToTry { get; set; } = 3;
+    public int LMP_BaseMovesToTry { get; set; } = 0;
+
+    public int LMP_MovesDepthMultiplier { get; set; } = 10;
 
     public int History_MaxMoveValue { get; set; } = 8_192;
 
diff --git a/src/Lynx/Search/NegaMax.cs b/src/Lynx/Search/NegaMax.cs
index 573d75084..c0d281bef 100644
--- a/src/Lynx/Search/NegaMax.cs
+++ b/src/Lynx/Search/NegaMax.cs
@@ -182,20 +182,20 @@ private int NegaMax(int depth, int ply, int alpha, int beta, bool parentWasNullM
             }
         }
 
-        for (int i = 0; i < pseudoLegalMoves.Length; ++i)
+        for (int moveIndex = 0; moveIndex < pseudoLegalMoves.Length; ++moveIndex)
         {
             // Incremental move sorting, inspired by https://github.com/jw1912/Chess-Challenge and suggested by toanth
             // There's no need to sort all the moves since most of them don't get checked anyway
             // So just find the first unsearched one with the best score and try it
-            for (int j = i + 1; j < pseudoLegalMoves.Length; j++)
+            for (int j = moveIndex + 1; j < pseudoLegalMoves.Length; j++)
             {
-                if (scores[j] > scores[i])
+                if (scores[j] > scores[moveIndex])
                 {
-                    (scores[i], scores[j], pseudoLegalMoves[i], pseudoLegalMoves[j]) = (scores[j], scores[i], pseudoLegalMoves[j], pseudoLegalMoves[i]);
+                    (scores[moveIndex], scores[j], pseudoLegalMoves[moveIndex], pseudoLegalMoves[j]) = (scores[j], scores[moveIndex], pseudoLegalMoves[j], pseudoLegalMoves[moveIndex]);
                 }
             }
 
-            var move = pseudoLegalMoves[i];
+            var move = pseudoLegalMoves[moveIndex];
 
             var gameState = position.MakeMove(move);
 
@@ -236,8 +236,8 @@ private int NegaMax(int depth, int ply, int alpha, int beta, bool parentWasNullM
                 if (!pvNode
                     && !isInCheck
                     && depth <= Configuration.EngineSettings.LMP_MaxDepth
-                    && scores[i] < EvaluationConstants.PromotionMoveScoreValue  // Quiet moves
-                    && i >= Configuration.EngineSettings.LMP_BaseMovesToTry + 10 * depth) // Based on SP and Altair
+                    && scores[moveIndex] < EvaluationConstants.PromotionMoveScoreValue  // Quiet moves
+                    && moveIndex >= Configuration.EngineSettings.LMP_BaseMovesToTry + (Configuration.EngineSettings.LMP_MovesDepthMultiplier * depth)) // Based on SP and Altair
                 {
                     // After making a move
                     Game.HalfMovesWithoutCaptureOrPawnMove = oldValue;