From: Jonathan Calovski <jonoface@live.com.au>
Date: Sat, 3 Oct 2015 10:36:51 +0000 (-0700)
Subject: Bonus for checking moves
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=9f5b31c21df72f60ab02417940ae573621ee7b90

Bonus for checking moves

STC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 14531 W: 2765 L: 2576 D: 9190

LTC:
LLR: 3.20 (-2.94,2.94) [0.00,5.00]
Total: 52518 W: 8107 L: 7782 D: 36629

Bench: 7556477

Resolves #435
---

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 4626a2ab..130b0e0a 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -184,6 +184,7 @@ namespace {
   const Score Unstoppable        = S( 0, 20);
   const Score Hanging            = S(31, 26);
   const Score PawnAttackThreat   = S(20, 20);
+  const Score Checked            = S(20, 20);
 
   // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
   // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
@@ -440,22 +441,34 @@ namespace {
         // Enemy queen safe checks
         b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
         if (b)
+        {
             attackUnits += QueenCheck * popcount<Max15>(b);
+            score -= Checked;
+        }
 
         // Enemy rooks safe checks
         b = b1 & ei.attackedBy[Them][ROOK];
         if (b)
+        {
             attackUnits += RookCheck * popcount<Max15>(b);
+            score -= Checked;
+        }
 
         // Enemy bishops safe checks
         b = b2 & ei.attackedBy[Them][BISHOP];
         if (b)
+        {
             attackUnits += BishopCheck * popcount<Max15>(b);
+            score -= Checked;
+        }
 
         // Enemy knights safe checks
         b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
         if (b)
+        {
             attackUnits += KnightCheck * popcount<Max15>(b);
+            score -= Checked;
+        }
 
         // Finally, extract the king danger score from the KingDanger[]
         // array and subtract the score from evaluation.