X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=849185b67e497246048fdf508e040b1cf58b48b4;hp=4d47b7e6df64a681bdc1b979626a04d942643d32;hb=f30f384757499508ebc670a1c58b99737e2449db;hpb=0439a79566d03065317b2025b9b479b9ae9f2d65

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 4d47b7e6..849185b6 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -167,8 +167,8 @@ namespace {
   // happen in Chess960 games.
   const Score TrappedBishopA1H1Penalty = make_score(100, 100);
 
-  // Penalty for BNR that is not defended by anything
-  const Score UndefendedPiecePenalty = make_score(25, 10);
+  // Penalty for an undefended bishop or knight
+  const Score UndefendedMinorPenalty = make_score(25, 10);
 
   // The SpaceMask[Color] contains the area of the board which is considered
   // by the space evaluation. In the middle game, each side is given a bonus
@@ -371,7 +371,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   margins[WHITE] = margins[BLACK] = VALUE_ZERO;
 
   // Probe the material hash table
-  ei.mi = Threads[pos.this_thread()].materialTable.probe(pos);
+  ei.mi = pos.this_thread()->materialTable.probe(pos);
   score += ei.mi->material_value();
 
   // If we have a specialized evaluation function for the current material
@@ -383,7 +383,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   }
 
   // Probe the pawn hash table
-  ei.pi = Threads[pos.this_thread()].pawnTable.probe(pos);
+  ei.pi = pos.this_thread()->pawnTable.probe(pos);
   score += ei.pi->pawns_value();
 
   // Initialize attack and king safety bitboards
@@ -676,18 +676,17 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b, undefended, undefendedMinors, weakEnemies;
+    Bitboard b, undefendedMinors, weakEnemies;
     Score score = SCORE_ZERO;
 
-    // Undefended pieces get penalized even if not under attack
-    undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
-    undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
+    // Undefended minors get penalized even if not under attack
+    undefendedMinors =  pos.pieces(Them)
+                      & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
+                      & ~ei.attackedBy[Them][0];
 
     if (undefendedMinors)
-        score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
-                                              : UndefendedPiecePenalty * 2;
-    if (undefended & pos.pieces(ROOK))
-        score += UndefendedPiecePenalty;
+        score += single_bit(undefendedMinors) ? UndefendedMinorPenalty
+                                              : UndefendedMinorPenalty * 2;
 
     // Enemy pieces not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)