X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=1b2defa54662a34718bb46c79e40ae9abffbe595;hp=22c17173c5727cd016a0bca109f7c2f62cc9c3a7;hb=d23454854e72e1311363a8c98cd58a5d44c427f9;hpb=2097cd12217a0e18c59bd88424ca613572e6feb2

diff --git a/src/position.cpp b/src/position.cpp
index 22c17173..1b2defa5 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1151,6 +1151,11 @@ int Position::see(Move m) const {
   return do_see<false>(m, 0);
 }
 
+/// Position::see_asymm() takes tempi into account.
+/// If the side who initiated the capturing sequence does the last capture,
+/// he loses a tempo. In this case if the result is below asymmThreshold 
+/// the capturing sequence is considered bad.
+
 int Position::see_asymm(Move m, int asymmThreshold) const
 {
   return do_see<true>(m, asymmThreshold);
@@ -1234,13 +1239,15 @@ int Position::do_see(Move m, int asymmThreshold) const {
 
   } while (stmAttackers);
 
-  // FIXME: Document
+  // If we are doing asymmetric SEE evaluation and the same side does the first
+  // and the last capture, he loses a tempo and gain must be at least worth "asymmThreshold".
+  // If not, we replace the score with a very low value, before negamaxing.
   if (Asymmetric)
   {
-      for (int i = 0; i < slIndex ; slIndex += 2)
+      for (int i = 0; i < slIndex ; i += 2)
       {
-          if (swapList[slIndex] < asymmThreshold)
-               swapList[slIndex] = - QueenValueMg * 16;
+          if (swapList[i] < asymmThreshold)
+               swapList[i] = - QueenValueMg * 16;
       }
   }