From: Chris Caino <chricainogithub@gmail.com>
Date: Mon, 4 Nov 2013 12:44:42 +0000 (+0000)
Subject: Zero redundant material imbalance terms
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=1064288b38d8b870601e1cd7393358db6bbb3a0e

Zero redundant material imbalance terms

First coefficient in the SameColor array does an
equivalent job when folded into the LinearCoefficients
array.

All of the diagonal terms in the OppositeColor array
are redundant due to cancellation.

No functional change.
---

diff --git a/src/material.cpp b/src/material.cpp
index 8a7fcb8d..1e751a86 100644
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -39,11 +39,11 @@ namespace {
   const Value RedundantRook  = Value(554);
 
   //                                  pair  pawn knight bishop rook queen
-  const int LinearCoefficients[6] = { 1817, -162, -1122, -190,  105,  26 };
+  const int LinearCoefficients[6] = { 1824, -162, -1122, -190,  105,  26 };
 
   const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
     // pair pawn knight bishop rook queen
-    {   7                               }, // Bishop pair
+    {   0                               }, // Bishop pair
     {  39,    2                         }, // Pawn
     {  35,  271,  -4                    }, // Knight
     {   7,  105,   4,    7              }, // Bishop
@@ -54,12 +54,12 @@ namespace {
   const int QuadraticCoefficientsOppositeColor[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
-    {  41                               }, // Bishop pair
-    {  37,   41                         }, // Pawn
-    {  10,   62,  41                    }, // Knight      OUR PIECES
-    {  57,   64,  39,    41             }, // Bishop
-    {  50,   40,  23,   -22,   41       }, // Rook
-    { 106,  101,   3,   151,  171,   41 }  // Queen
+    {   0                               }, // Bishop pair
+    {  37,    0                         }, // Pawn
+    {  10,   62,   0                    }, // Knight      OUR PIECES
+    {  57,   64,  39,     0             }, // Bishop
+    {  50,   40,  23,   -22,    0       }, // Rook
+    { 106,  101,   3,   151,  171,    0 }  // Queen
   };
 
   // Endgame evaluation and scaling functions accessed direcly and not through