From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Wed, 23 Dec 2020 15:57:27 +0000 (+0100)
Subject: Simplify losing chess material evaluation
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=00fe00f664824d862fae1976f5110d523d697d78;p=fairystockfish.git

Simplify losing chess material evaluation

giveaway STC
LLR: 2.97 (-2.94,2.94) [-10.00,5.00]
Total: 922 W: 372 L: 323 D: 227
http://www.variantfishtest.org:6543/tests/view/5fe330d46e23db221d9e967c

giveaway LTC
LLR: 2.98 (-2.94,2.94) [-10.00,5.00]
Total: 1718 W: 652 L: 609 D: 457
http://www.variantfishtest.org:6543/tests/view/5fe346dd6e23db221d9e9688

losers STC
LLR: 2.99 (-2.94,2.94) [-10.00,5.00]
Total: 485 W: 241 L: 183 D: 61
http://www.variantfishtest.org:6543/tests/view/5fe346ee6e23db221d9e968a

losers LTC
LLR: 2.96 (-2.94,2.94) [-10.00,5.00]
Total: 547 W: 273 L: 215 D: 59
http://www.variantfishtest.org:6543/tests/view/5fe34b7d6e23db221d9e968c
---

diff --git a/src/material.cpp b/src/material.cpp
index 1318ba3..539791c 100644
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -103,7 +103,7 @@ namespace {
     // Second-degree polynomial material imbalance, by Tord Romstad
     for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
     {
-        if (!pieceCount[Us][pt1] || (pos.extinction_value() == VALUE_MATE && pt1 != KNIGHT))
+        if (!pieceCount[Us][pt1])
             continue;
 
         int v = QuadraticOurs[pt1][pt1] * pieceCount[Us][pt1];
@@ -116,7 +116,7 @@ namespace {
     }
 
     if (pos.must_capture())
-        bonus += bonus + 2 * QuadraticOurs[KNIGHT][PAWN] * pieceCount[Us][KNIGHT] * pieceCount[Us][PAWN];
+        bonus += 3 * QuadraticOurs[KNIGHT][PAWN] * pieceCount[Us][KNIGHT] * pieceCount[Us][PAWN];
     else if (pos.check_counting())
         bonus -= 2 * QuadraticOurs[PAWN][PAWN] * pieceCount[Us][PAWN] * pieceCount[Us][PAWN];