X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=17d52cae5febf53739f97e78e0ab254e3e7d5b83;hb=c86eee391830c9c74bc11be9c537ccbbf6cb412e;hp=c9f1aee0685be46653a04758ed1693ef6f6f1995;hpb=10b53e1c5e6aeba156eb5c02afccfd7db1f84d16;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index c9f1aee0..17d52cae 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -937,7 +937,7 @@ moves_loop: // When in check and at SpNode search starts from here
 
       // Step 15. Reduced depth search (LMR). If the move fails high will be
       // re-searched at full depth.
-      if (    depth > 3 * ONE_PLY
+      if (    depth >= 3 * ONE_PLY
           && !pvMove
           && !captureOrPromotion
           &&  move != ttMove
@@ -1361,7 +1361,10 @@ moves_loop: // When in check and at SpNode search starts from here
     Square m2to = to_sq(second);
 
     // The piece is the same or second's destination was vacated by the first move
-    if (m1to == m2from || m2to == m1from)
+    // We exclude the trivial case where a sliding piece does in two moves what
+    // it could do in one move: eg. Ra1a2, Ra2a3.
+    if (    m2to == m1from
+        || (m1to == m2from && !squares_aligned(m1from, m2from, m2to)))
         return true;
 
     // Second one moves through the square vacated by first one