X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=42c1adff71591a270148adb43b37d2588cd2fe29;hp=b6dc31b4ed0cfa6271d719da333f3c4d94a4ad05;hb=ba4e215493de31263b9bd352af79d00193e545bf;hpb=043a469f83b4c81f94ab991029b4cd49fb05452e

diff --git a/src/position.cpp b/src/position.cpp
index b6dc31b4..42c1adff 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -272,7 +272,7 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
   // 5-6. Halfmove clock and fullmove number
   ss >> std::skipws >> st->rule50 >> gamePly;
 
-  // Convert from fullmove starting from 1 to ply starting from 0,
+  // Convert from fullmove starting from 1 to gamePly starting from 0,
   // handle also common incorrect FEN with fullmove = 0.
   gamePly = std::max(2 * (gamePly - 1), 0) + (sideToMove == BLACK);
 
@@ -1071,11 +1071,10 @@ bool Position::is_draw(int ply) const {
   {
       stp = stp->previous->previous;
 
-      // At root position ply is 1, so return a draw score if a position
-      // repeats once earlier but strictly after the root, or repeats twice
-      // before or at the root.
+      // Return a draw score if a position repeats once earlier but strictly
+      // after the root, or repeats twice before or at the root.
       if (   stp->key == st->key
-          && ++cnt + (ply - 1 > i) == 2)
+          && ++cnt + (ply > i) == 2)
           return true;
   }