King proximity tweak for passed pawns

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index e42b4f387ccafc533952586f863a221a5ddca908..1988e20ec50ce117fc72fcdc7aa9691ef5d2694e 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -602,8 +602,8 @@ namespace {
             Square blockSq = s + Up;
 
             // Adjust bonus based on the king's proximity
-            bonus += make_score(0, (  king_proximity(Them, blockSq) * 5
-                                    - king_proximity(Us,   blockSq) * 2) * w);
+            bonus += make_score(0, (  (king_proximity(Them, blockSq) * 19) / 4
+                                     - king_proximity(Us,   blockSq) *  2) * w);
 
             // If blockSq is not the queening square then consider also a second push
             if (r != RANK_7)