Big King Safety tuning

All king safety related terms (shelterweakness, stormdanger,
attackunits, ..) was tuned together. Additionally for attack units a
finer granularity (factor 4) is used.

STC
ELO: 9.22 +-3.1 (95%) LOS: 100.0%
Total: 19514 W: 4340 L: 3822 D: 11352

LTC
LLR: 2.96 (-2.94,2.94) [0.00,6.00]
Total: 6399 W: 1192 L: 1056 D: 4151

Bench: 8224782

Resolves #184

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index e4c2bbcb6365a9b5e5744960a4eaa689ade2312d..1c27b29d8075728fe77dc56a2f1c805e728836f8 100644 (file)
--- 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}, {318, 0}
+    {289, 344}, {233, 201}, {221, 273}, {46, 0}, {321, 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, 2, 2, 3, 5 };
+  const int KingAttackWeights[] = { 0, 0, 6, 2, 5, 5 };
 
   // Bonuses for enemy's safe checks
-  const int QueenContactCheck = 24;
-  const int RookContactCheck  = 16;
-  const int QueenCheck        = 12;
-  const int RookCheck         = 8;
-  const int BishopCheck       = 2;
-  const int KnightCheck       = 3;
+  const int QueenContactCheck = 92;
+  const int RookContactCheck  = 68;
+  const int QueenCheck        = 50;
+  const int RookCheck         = 36;
+  const int BishopCheck       = 7;
+  const int KnightCheck       = 14;
 
   // KingDanger[attackUnits] contains the actual king danger weighted
   // scores, indexed by a calculated integer number.
@@ -411,11 +411,12 @@ 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(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
-                     + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
-                     + 2 * (ei.pinnedPieces[Us] != 0)
-                     - mg_value(score) / 32
-                     - !pos.count<QUEEN>(Them) * 15;
+        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
+                     - !pos.count<QUEEN>(Them) * 60;
 
         // Analyse the enemy's safe queen contact checks. Firstly, find the
         // undefended squares around the king reachable by the enemy queen...
@@ -475,7 +476,7 @@ namespace {
 
         // Finally, extract the king danger score from the KingDanger[]
         // array and subtract the score from evaluation.
-        score -= KingDanger[std::max(std::min(attackUnits, 99), 0)];
+        score -= KingDanger[std::max(std::min(attackUnits / 4, 99), 0)];
     }
 
     if (Trace)

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 3d98c0124a512c0c843ea7f728138d3b370e48fb..80dead4fb5378b00068320139ed59861417b11ab 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -62,33 +62,33 @@ namespace {
 
   // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
   const Value ShelterWeakness[][RANK_NB] = {
-  { V(101), V(10), V(24), V(68), V(90), V( 95), V(102) },
-  { V(105), V( 1), V(30), V(76), V(95), V(100), V(105) },
-  { V( 99), V( 0), V(32), V(72), V(92), V(101), V(100) },
-  { V( 94), V( 1), V(31), V(68), V(89), V( 98), V(106) } };
+  { 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) } };
 
   // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
   const Value StormDanger[][4][RANK_NB] = {
-  { { V( 0),  V(  61), V( 128), V(47), V(27) },
-    { V( 0),  V(  66), V( 131), V(49), V(27) },
-    { V( 0),  V(  62), V( 126), V(52), V(23) },
-    { V( 0),  V(  63), V( 128), V(52), V(26) } },
-  { { V(25),  V(  33), V(  95), V(39), V(21) },
-    { V(24),  V(  33), V(  97), V(42), V(22) },
-    { V(24),  V(  33), V(  93), V(35), V(23) },
-    { V(26),  V(  27), V(  96), V(37), V(22) } },
-  { { V( 0),  V(   0), V(  80), V(14), V( 8) },
-    { V( 0),  V(   0), V( 163), V(28), V(12) },
-    { V( 0),  V(   0), V( 163), V(25), V(15) },
-    { V( 0),  V(   0), V( 161), V(24), V(14) } },
-  { { V( 0),  V(-300), V(-300), V(54), V(23) },
-    { V( 0),  V(  67), V( 128), V(46), V(24) },
-    { V( 0),  V(  64), V( 130), V(50), V(29) },
-    { V( 0),  V(  63), V( 127), V(51), V(24) } } };
+  { { 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) } } };
 
   // 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(261);
+  const Value MaxSafetyBonus = V(257);
 
   #undef S
   #undef V