Revert "Symmetric king safety"

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 34a87771aea96a120e14f5858ffebd510f73d60f..64b1bf4cf750d8d0902ce6f9d22c189eb175480b 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -169,7 +169,6 @@ namespace {
   const Score RookSemiopenFile = make_score(19, 10);
   const Score BishopPawns      = make_score( 8, 12);
   const Score MinorBehindPawn  = make_score(16,  0);
-  const Score UndefendedMinor  = make_score(25, 10);
   const Score TrappedRook      = make_score(90,  0);
   const Score Unstoppable      = make_score( 0, 20);
 
@@ -520,16 +519,9 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b, undefendedMinors, weakEnemies;
+    Bitboard b, weakEnemies;
     Score score = SCORE_ZERO;
 
-    // Undefended minors get penalized even if they are not under attack
-    undefendedMinors =  pos.pieces(Them, BISHOP, KNIGHT)
-                      & ~ei.attackedBy[Them][ALL_PIECES];
-
-    if (undefendedMinors)
-        score += UndefendedMinor;
-
     // Enemies not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
                  & ~ei.attackedBy[Them][PAWN]
@@ -787,13 +779,6 @@ namespace {
              sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
     }
 
-    // Stealmate detection
-    Color stm = pos.side_to_move();
-    if (   (ei.attackedBy[stm][ALL_PIECES] == ei.attackedBy[stm][KING])
-        && (!(ei.attackedBy[stm][KING] & ~ei.attackedBy[~stm][ALL_PIECES]))
-        && !MoveList<LEGAL>(pos).size())
-        sf = SCALE_FACTOR_DRAW;
-
     // Interpolate between a middlegame and a (scaled by 'sf') endgame score
     Value v =  mg_value(score) * int(ei.mi->game_phase())
              + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL;