Score non-captures only by history

Now that history can go negative and is almost alwyas
non zero we have no more reasons to use also psqt term.

After 994 games at 1+0
Mod vs Orig +204 =597 -193 +4 ELO

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

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 638f81757d2af94d72c9b0c6739ab1d191d2c6f5..901aa60e5625c766b797fd88d4dec2888b24ac69 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -213,7 +213,6 @@ void MovePicker::score_noncaptures() {
   Move m;
   Piece piece;
   Square from, to;
-  int hs;
 
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
@@ -221,14 +220,7 @@ void MovePicker::score_noncaptures() {
       from = move_from(m);
       to = move_to(m);
       piece = pos.piece_on(from);
-      hs = H.move_ordering_score(piece, to);
-
-      // Ensure history is always preferred to pst
-      if (hs > 0)
-          hs += 1000;
-
-      // pst based scoring
-      cur->score = hs + mg_value(pos.pst_delta(piece, from, to));
+      cur->score = H.move_ordering_score(piece, to);
   }
 }