Refine "few moves" in "last minute surprise"

It seems that "few moves" works because we extend the good
captures at the last ply of PV, so code it directly.

This version seems defenitly stronger then previous one.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/movepick.h b/src/movepick.h
index 66518ac76861fff4d34a41078e89fa690631100d..5a38826188811eb634f053d5cd3396760325d69f 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -7,11 +7,7 @@
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
-<<<<<<< HEAD:src/movepick.h
 
-=======
-  
->>>>>>> d3600c39a745179ed6b094b305d0645e83a1ee86:src/movepick.h
   Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
@@ -54,7 +50,7 @@ public:
     PH_TT_MOVE,        // Transposition table move
     PH_MATE_KILLER,    // Mate killer from the current ply
     PH_GOOD_CAPTURES,  // Queen promotions and captures with SEE values >= 0
-    PH_BAD_CAPTURES,   // Queen promotions and captures with SEE valuse <= 0
+    PH_BAD_CAPTURES,   // Queen promotions and captures with SEE values < 0
     PH_KILLER_1,       // Killer move 1 from the current ply (not used yet).
     PH_KILLER_2,       // Killer move 2 from the current ply (not used yet).
     PH_NONCAPTURES,    // Non-captures and underpromotions

diff --git a/src/search.cpp b/src/search.cpp
index f29041847c0ae033cc4b25d403f266fc633a15f5..fca3d2c9dbc431a89f1acdf9e764fa0f18ada6fd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -931,7 +931,7 @@ namespace {
     {
       assert(move_is_ok(move));
 
-      bool fewMoves = (depth <= OnePly && mp.number_of_moves() < 4);
+      bool lastMinuteSurprise = (depth <= OnePly && mp.current_move_type() == MovePicker::PH_GOOD_CAPTURES);
       bool singleReply = (pos.is_check() && mp.number_of_moves() == 1);
       bool moveIsCheck = pos.move_is_check(move, dcCandidates);
       bool moveIsCapture = pos.move_is_capture(move);
@@ -943,7 +943,7 @@ namespace {
         PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
 
       // Decide the new search depth
-      Depth ext = extension(pos, move, true, moveIsCheck, singleReply || fewMoves, mateThreat);
+      Depth ext = extension(pos, move, true, moveIsCheck, singleReply || lastMinuteSurprise, mateThreat);
       Depth newDepth = depth - OnePly + ext;
 
       // Make and search the move