X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=9739a0018ab24861f5fea5d811cd3bd2ad2b3823;hp=da4b9c30b41c3e9d3f4ac17641e7a8fcb3f28233;hb=d30994ecd54bf96db88016fb6d92ff2c4614bc2e;hpb=8fb45caadef67fb2ccc27857c15ade987d9f5e2f

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index da4b9c30..9739a001 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -384,14 +384,17 @@ namespace {
     // Main king safety evaluation
     if (ei.kingAttackersCount[Them])
     {
-        // Find the attacked squares around the king which have no defenders
-        // apart from the king itself.
+        // Find the attacked squares which are defended only by the king...
         undefended =  ei.attackedBy[Them][ALL_PIECES]
                     & ei.attackedBy[Us][KING]
                     & ~(  ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
                         | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
                         | ei.attackedBy[Us][QUEEN]);
 
+        // ... and those which are not defended at all in the larger king ring
+        b =  ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES]
+           & ei.kingRing[Us] & ~pos.pieces(Them);
+
         // Initialize the 'attackUnits' variable, which is used later on as an
         // index into the KingDanger[] array. The initial value is based on the
         // number and types of the enemy's attacking pieces, the number of
@@ -400,7 +403,7 @@ namespace {
         attackUnits =  std::min(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
                      +  9 * ei.kingAdjacentZoneAttacksCount[Them]
                      + 27 * popcount(undefended)
-                     + 11 * !!ei.pinnedPieces[Us]
+                     + 11 * (popcount(b) + !!ei.pinnedPieces[Us])
                      - 64 * !pos.count<QUEEN>(Them)
                      - mg_value(score) / 8;
 
@@ -611,9 +614,6 @@ namespace {
                 mbonus += rr + r * 2, ebonus += rr + r * 2;
         } // rr != 0
 
-        if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
-            ebonus += ebonus / 4;
-
         score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
     }