Add "Best Book Move" UCI option

[stockfish] / src / book.cpp

diff --git a/src/book.cpp b/src/book.cpp
index 20861988b24c906b1ba04c5788b6dc9014a553ca..dbd037885711c191b23d53622a6b6aa8db75dba9 100644 (file)
--- a/src/book.cpp
+++ b/src/book.cpp
@@ -399,14 +399,15 @@ const string Book::file_name() { // Not const to compile on HP-UX 11.X
 /// Book::get_move() gets a book move for a given position. Returns
 /// MOVE_NONE if no book move is found.
 
 /// Book::get_move() gets a book move for a given position. Returns
 /// MOVE_NONE if no book move is found.
 

-Move Book::get_move(const Position& pos) {
+Move Book::get_move(const Position& pos, bool findBestMove) {

 
   if (!is_open() || bookSize == 0)
       return MOVE_NONE;
 
 
   if (!is_open() || bookSize == 0)
       return MOVE_NONE;
 

-  int bookMove = 0, scoresSum = 0;
-  uint64_t key = book_key(pos);

   BookEntry entry;
   BookEntry entry;

+  int bookMove = MOVE_NONE;
+  int scoresSum = 0, bestScore = 0;
+  uint64_t key = book_key(pos);

 
   // Choose a book move among the possible moves for the given position
   for (int idx = find_key(key); idx < bookSize; idx++)
 
   // Choose a book move among the possible moves for the given position
   for (int idx = find_key(key); idx < bookSize; idx++)


@@ -419,6 +420,17 @@ Move Book::get_move(const Position& pos) {
 
       assert(score > 0);
 
 
       assert(score > 0);
 

+      // If findBestMove is true choose highest rated book move
+      if (findBestMove)
+      {
+          if (score > bestScore)
+          {
+              bestScore = score;
+              bookMove = entry.move;
+          }
+          continue;
+      }
+

       // Choose book move according to its score. If a move has a very
       // high score it has more probability to be choosen then a one with
       // lower score. Note that first entry is always chosen.
       // Choose book move according to its score. If a move has a very
       // high score it has more probability to be choosen then a one with
       // lower score. Note that first entry is always chosen.