Simplify away king infiltration.

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 8d7976d577340842a736b1e94abdddc7a8827d54..17597648bf36393fa2067ccbaf2ee071c33e51d2 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -145,7 +145,7 @@ namespace {
   constexpr Score ThreatByKing       = S( 24, 89);
   constexpr Score ThreatByPawnPush   = S( 48, 39);
   constexpr Score ThreatBySafePawn   = S(173, 94);
-  constexpr Score TrappedRook        = S( 52, 30);
+  constexpr Score TrappedRook        = S( 52, 10);
   constexpr Score WeakQueen          = S( 49, 15);
 
 #undef S
@@ -524,7 +524,7 @@ namespace {
     b =   attackedBy[Them][ALL_PIECES]
        & ~stronglyProtected
        &  attackedBy[Us][ALL_PIECES];
-    score += RestrictedPiece * (popcount(b) + popcount(b & pos.pieces()));
+    score += RestrictedPiece * popcount(b);
 
     // Protected or unattacked squares
     safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES];
@@ -701,9 +701,6 @@ namespace {
     int outflanking =  distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
                      - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
 
-    bool infiltration =   rank_of(pos.square<KING>(WHITE)) > RANK_4
-                       || rank_of(pos.square<KING>(BLACK)) < RANK_5;
-
     bool pawnsOnBothFlanks =   (pos.pieces(PAWN) & QueenSide)
                             && (pos.pieces(PAWN) & KingSide);
 
@@ -715,14 +712,12 @@ namespace {
     int complexity =   9 * pe->passed_count()
                     + 11 * pos.count<PAWN>()
                     +  9 * outflanking
-                    + 12 * infiltration
                     + 21 * pawnsOnBothFlanks
                     + 51 * !pos.non_pawn_material()
                     - 43 * almostUnwinnable
-                    - 100 ;
+                    - 95 ;
 
     // Give more importance to non-material score
-    score = score - pos.psq_score() / 2;
     Value mg = mg_value(score);
     Value eg = eg_value(score);