Simplify extensions

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 0b87b456b72054d3583f03fc09aa6548d5ec3e4a..789492fd95225965194b8262affc992978ea53de 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -829,13 +829,10 @@ moves_loop: // When in check and at SpNode search starts from here
                  || pos.is_passed_pawn_push(move)
                  || type_of(move) == CASTLE;
 
-      // Step 12. Extend checks and, in PV nodes, also dangerous moves
-      if (PvNode && dangerous)
+      // Step 12. Extend checks
+      if (givesCheck && pos.see_sign(move) >= 0)
           ext = ONE_PLY;
 
-      else if (givesCheck && pos.see_sign(move) >= 0)
-          ext = inCheck || ss->staticEval <= alpha ? ONE_PLY : ONE_PLY / 2;
-
       // Singular extension search. If all moves but one fail low on a search of
       // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
       // is singular and should be extended. To verify this we do a reduced search