From: FauziAkram <fauzi.dabat@hotmail.com>
Date: Fri, 7 Aug 2020 00:37:54 +0000 (-0700)
Subject: Tuned pawn values
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=af935365e3e528f445c1c0f48bb43b8cf685719c

Tuned pawn values

Passed STC:
https://tests.stockfishchess.org/tests/view/5f2aa49fa5abc164f05e4d1b
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 40888 W: 7977 L: 7726 D: 25185
Ptnml(0-2): 665, 4806, 9333, 4893, 747

Passed LTC:
https://tests.stockfishchess.org/tests/view/5f2b1059b3ebe5cbfee85ae7
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 51264 W: 6445 L: 6134 D: 38685
Ptnml(0-2): 328, 4564, 15580, 4789, 371

closes https://github.com/official-stockfish/Stockfish/pull/2920

bench: 4314943
---

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 73682529..868d0c8e 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -30,21 +30,21 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Pawn penalties
-  constexpr Score Backward      = S( 9, 24);
-  constexpr Score Doubled       = S(11, 56);
-  constexpr Score Isolated      = S( 5, 15);
-  constexpr Score WeakLever     = S( 0, 56);
-  constexpr Score WeakUnopposed = S(13, 27);
+  constexpr Score Backward      = S( 8, 27);
+  constexpr Score Doubled       = S(11, 55);
+  constexpr Score Isolated      = S( 5, 17);
+  constexpr Score WeakLever     = S( 2, 54);
+  constexpr Score WeakUnopposed = S(15, 25);
 
   // Bonus for blocked pawns at 5th or 6th rank
-  constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) };
+  constexpr Score BlockedPawn[2] = { S(-13, -4), S(-4, 3) };
 
   constexpr Score BlockedStorm[RANK_NB] = {
     S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
   };
 
   // Connected pawn bonus
-  constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
+  constexpr int Connected[RANK_NB] = { 0, 7, 8, 11, 24, 45, 85 };
 
   // Strength of pawn shelter for our king by [distance from edge][rank].
   // RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
diff --git a/src/types.h b/src/types.h
index 379859f7..73da41e2 100644
--- a/src/types.h
+++ b/src/types.h
@@ -178,7 +178,7 @@ enum Value : int {
   VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - MAX_PLY,
   VALUE_MATED_IN_MAX_PLY = -VALUE_MATE_IN_MAX_PLY,
 
-  PawnValueMg   = 124,   PawnValueEg   = 206,
+  PawnValueMg   = 126,   PawnValueEg   = 208,
   KnightValueMg = 781,   KnightValueEg = 854,
   BishopValueMg = 825,   BishopValueEg = 915,
   RookValueMg   = 1276,  RookValueEg   = 1380,