King safety tuning with values obtained by SPSA.

Part I: LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 11529 W: 2075 L: 1882 D: 7572 Part II: LTC: ELO: 2.07 +-2.1 (95%) LOS: 97.3% Total: 34859 W: 5967 L: 5759 D: 23133 Bench: 7374604 Resolves #228
official-stockfish · Jan 28, 2015 · 7837fb2 · 7837fb2
1 parent 9f0d524
commit 7837fb2
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Showing 2 changed files with 36 additions and 36 deletions.
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
@@ -91,7 +91,7 @@ namespace {
   // Evaluation weights, indexed by evaluation term
   enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety };
   const struct Weight { int mg, eg; } Weights[] = {
-    {289, 344}, {233, 201}, {221, 273}, {46, 0}, {321, 0}
+    {289, 344}, {233, 201}, {221, 273}, {46, 0}, {324, 0}
   };
 
   #define V(v) Value(v)
@@ -186,15 +186,15 @@ namespace {
   // index to KingDanger[].
   //
   // KingAttackWeights[PieceType] contains king attack weights by piece type
-  const int KingAttackWeights[] = { 0, 0, 6, 2, 5, 5 };
+  const int KingAttackWeights[] = { 0, 0, 8, 4, 4, 1 };
 
   // Bonuses for enemy's safe checks
-  const int QueenContactCheck = 92;
-  const int RookContactCheck  = 68;
-  const int QueenCheck        = 50;
-  const int RookCheck         = 36;
-  const int BishopCheck       = 7;
-  const int KnightCheck       = 14;
+  const int QueenContactCheck = 89;
+  const int RookContactCheck  = 72;
+  const int QueenCheck        = 51;
+  const int RookCheck         = 38;
+  const int BishopCheck       = 5;
+  const int KnightCheck       = 16;
 
   // KingDanger[attackUnits] contains the actual king danger weighted
   // scores, indexed by a calculated integer number.
@@ -411,11 +411,11 @@ namespace {
         // number and types of the enemy's attacking pieces, the number of
         // attacked and undefended squares around our king and the quality of
         // the pawn shelter (current 'score' value).
-        attackUnits =  std::min(77, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
-                     + 10 * ei.kingAdjacentZoneAttacksCount[Them]
-                     + 19 * popcount<Max15>(undefended)
-                     +  9 * (ei.pinnedPieces[Us] != 0)
-                     - mg_value(score) * 63 / 512
+        attackUnits =  std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+                     + 9 * ei.kingAdjacentZoneAttacksCount[Them]
+                     + 25 * popcount<Max15>(undefended)
+                     +  10 * (ei.pinnedPieces[Us] != 0)
+                     - mg_value(score) / 8
                      - !pos.count<QUEEN>(Them) * 60;
 
         // Analyse the enemy's safe queen contact checks. Firstly, find the
@@ -891,13 +891,13 @@ namespace Eval {
 
   void init() {
 
-    const double MaxSlope = 7.5;
+    const double MaxSlope = 8.5;
     const double Peak = 1280;
     double t = 0.0;
 
     for (int i = 1; i < 400; ++i)
     {
-        t = std::min(Peak, std::min(0.025 * i * i, t + MaxSlope));
+        t = std::min(Peak, std::min(0.027 * i * i, t + MaxSlope));
         KingDanger[i] = apply_weight(make_score(int(t), 0), Weights[KingSafety]);
     }
   }

diff --git a/src/pawns.cpp b/src/pawns.cpp
@@ -63,33 +63,33 @@ namespace {
 
   // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
   const Value ShelterWeakness[][RANK_NB] = {
-  { V(100), V(13), V(24), V(64), V(89), V( 93), V(104) },
-  { V(110), V( 1), V(29), V(75), V(96), V(102), V(107) },
-  { V(102), V( 0), V(39), V(74), V(88), V(101), V( 98) },
-  { V( 88), V( 4), V(33), V(67), V(92), V( 94), V(107) } };
+  { V( 99), V(23), V(24), V(54), V(85), V( 93), V(107) },
+  { V(119), V( 2), V(28), V(72), V(96), V(104), V(114) },
+  { V(103), V( 6), V(47), V(74), V(84), V(103), V( 94) },
+  { V( 78), V(10), V(41), V(64), V(88), V( 92), V(115) } };
 
   // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
   const Value StormDanger[][4][RANK_NB] = {
-  { { V( 0),  V(  63), V( 128), V(43), V(27) },
-    { V( 0),  V(  62), V( 131), V(44), V(26) },
-    { V( 0),  V(  59), V( 121), V(50), V(28) },
-    { V( 0),  V(  62), V( 127), V(54), V(28) } },
-  { { V(24),  V(  40), V(  93), V(42), V(22) },
-    { V(24),  V(  28), V( 101), V(38), V(20) },
-    { V(24),  V(  32), V(  95), V(36), V(23) },
-    { V(27),  V(  24), V(  99), V(36), V(24) } },
-  { { V( 0),  V(   0), V(  81), V(16), V( 6) },
-    { V( 0),  V(   0), V( 165), V(29), V( 9) },
-    { V( 0),  V(   0), V( 163), V(23), V(12) },
-    { V( 0),  V(   0), V( 161), V(28), V(13) } },
-  { { V( 0),  V(-296), V(-299), V(55), V(25) },
-    { V( 0),  V(  67), V( 131), V(46), V(21) },
-    { V( 0),  V(  65), V( 135), V(50), V(31) },
-    { V( 0),  V(  62), V( 128), V(51), V(24) } } };
+  { { V( 0),  V(  65), V( 125), V(37), V(30) },
+    { V( 0),  V(  57), V( 136), V(39), V(24) },
+    { V( 0),  V(  50), V( 114), V(45), V(29) },
+    { V( 0),  V(  58), V( 129), V(56), V(34) } },
+  { { V(20),  V(  45), V(  91), V(47), V(20) },
+    { V(25),  V(  23), V( 105), V(38), V(14) },
+    { V(21),  V(  37), V(  99), V(35), V(21) },
+    { V(30),  V(  18), V( 105), V(38), V(28) } },
+  { { V( 0),  V(   0), V(  81), V(13), V( 4) },
+    { V( 0),  V(   0), V( 169), V(30), V( 4) },
+    { V( 0),  V(   0), V( 166), V(24), V( 6) },
+    { V( 0),  V(   0), V( 164), V(24), V(11) } },
+  { { V( 0),  V(-289), V(-297), V(57), V(29) },
+    { V( 0),  V(  66), V( 136), V(43), V(16) },
+    { V( 0),  V(  66), V( 141), V(50), V(31) },
+    { V( 0),  V(  63), V( 126), V(52), V(23) } } };
 
   // Max bonus for king safety. Corresponds to start position with all the pawns
   // in front of the king and no enemy pawn on the horizon.
-  const Value MaxSafetyBonus = V(257);
+  const Value MaxSafetyBonus = V(252);
 
   #undef S
   #undef V