From: Joona Kiiski <joona.kiiski@gmail.com>
Date: Fri, 23 Jul 2010 06:08:31 +0000 (+0300)
Subject: Retire 'Randomness' ucioption
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=d3260ce70f6a17f9d43d199f0e07488888188f8b

Retire 'Randomness' ucioption

Using multiple threads and good opening book is
much better and more reliable source of randomness than
spoiling psqt-tables

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

diff --git a/src/position.cpp b/src/position.cpp
index 17680697..537e574f 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1752,21 +1752,17 @@ void Position::init_zobrist() {
 
 
 /// Position::init_piece_square_tables() initializes the piece square tables.
-/// This is a two-step operation:  First, the white halves of the tables are
-/// copied from the MgPST[][] and EgPST[][] arrays, with a small random number
-/// added to each entry if the "Randomness" UCI parameter is non-zero.
+/// This is a two-step operation:
+/// First, the white halves of the tables are
+/// copied from the MgPST[][] and EgPST[][] arrays.
 /// Second, the black halves of the tables are initialized by mirroring
 /// and changing the sign of the corresponding white scores.
 
 void Position::init_piece_square_tables() {
 
-  int r = get_option_value_int("Randomness"), i;
   for (Square s = SQ_A1; s <= SQ_H8; s++)
       for (Piece p = WP; p <= WK; p++)
-      {
-          i = (r == 0)? 0 : (genrand_int32() % (r*2) - r);
-          PieceSquareTable[p][s] = make_score(MgPST[p][s] + i, EgPST[p][s] + i);
-      }
+          PieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]);
 
   for (Square s = SQ_A1; s <= SQ_H8; s++)
       for (Piece p = BP; p <= BK; p++)
diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index 84bcc832..6fdc6e77 100644
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -118,7 +118,6 @@ namespace {
     o["Passed Pawn Extension (non-PV nodes)"] = Option(0, 0, 2);
     o["Pawn Endgame Extension (PV nodes)"] = Option(2, 0, 2);
     o["Pawn Endgame Extension (non-PV nodes)"] = Option(2, 0, 2);
-    o["Randomness"] = Option(0, 0, 10);
     o["Minimum Split Depth"] = Option(4, 4, 7);
     o["Maximum Number of Threads per Split Point"] = Option(5, 4, 8);
     o["Threads"] = Option(1, 1, MAX_THREADS);