From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sun, 10 Mar 2019 15:25:37 +0000 (+0100)
Subject: Bonus for extinction piece types
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=ad94871361b746e6eb22177aefa610047169284f;p=fairystockfish.git

Bonus for extinction piece types

kinglet STC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 117 W: 104 L: 9 D: 4
http://35.161.250.236:6543/tests/view/5c84ed3d6e23db76ed2525af

giveaway STC
LLR: 2.94 (-2.94,2.94) [-10.00,5.00]
Total: 2220 W: 948 L: 905 D: 367
http://35.161.250.236:6543/tests/view/5c85020e6e23db76ed2525b2

extinction STC (failed)
LLR: -2.98 (-2.94,2.94) [-10.00,5.00]
Total: 939 W: 400 L: 471 D: 68
http://35.161.250.236:6543/tests/view/5c84ece66e23db76ed2525a8
---

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 9243055..afb8604 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -915,6 +915,16 @@ namespace {
         score += make_score(3000, 1000) / (remainingChecks * remainingChecks);
     }
 
+    // Extinction
+    if (pos.extinction_value() != VALUE_NONE)
+    {
+        for (PieceType pt : pos.extinction_piece_types())
+            if (pt != ALL_PIECES)
+                score += make_score(1000, 1000) / pos.count(Us, pt) * (pos.extinction_value() / VALUE_MATE);
+            else if (pos.extinction_value() == VALUE_MATE && !pos.count<KING>(Us))
+                score += make_score(5000, pos.non_pawn_material(Us)) / pos.count<ALL_PIECES>(Us);
+    }
+
     // Connect-n
     if (pos.connect_n() > 0)
     {