Add "Best Book Move" UCI option

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index efdb287fa740a3325c73771f6b43492345b5dd5e..0e65d19ff3c9f5d8da2d9fd7887ceb2bb42ec3e5 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -387,7 +387,7 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move,
       if (get_option_value_string("Book File") != OpeningBook.file_name())
           OpeningBook.open(get_option_value_string("Book File"));
 
-      Move bookMove = OpeningBook.get_move(pos);
+      Move bookMove = OpeningBook.get_move(pos, get_option_value_bool("Best Book Move"));
       if (bookMove != MOVE_NONE)
       {
           if (PonderSearch)
@@ -1713,7 +1713,7 @@ namespace {
 
       // Detect blocking evasions that are candidate to be pruned
       evasionPrunable =   isCheck
-                       && bestValue != -VALUE_INFINITE
+                       && bestValue > value_mated_in(PLY_MAX)
                        && !pos.move_is_capture(move)
                        && pos.type_of_piece_on(move_from(move)) != KING
                        && !pos.can_castle(pos.side_to_move());