From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Fri, 13 Mar 2020 15:14:34 +0000 (+0100)
Subject: Evaluate virtual piece drop checks in bughouse
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=04b743719b0025da26e2fca9741541aaa552f150;p=fairystockfish.git

Evaluate virtual piece drop checks in bughouse

bughouse
Total: 1000 W: 531 L: 459 D: 10
---

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index b871253..ff0b25b 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -514,7 +514,7 @@ namespace {
                 unsafeChecks |= knightChecks;
             break;
         case PAWN:
-            if (pos.piece_drops() && (pos.count_in_hand(Them, pt) || pos.two_boards()))
+            if (pos.piece_drops() && pos.count_in_hand(Them, pt))
             {
                 pawnChecks = attacks_bb(Us, pt, ksq, pos.pieces()) & ~pos.pieces() & pos.board_bb();
                 if (pawnChecks & safe)
@@ -535,6 +535,14 @@ namespace {
         }
     }
 
+    // Virtual piece drops
+    if (pos.two_boards() && pos.piece_drops())
+    {
+        for (PieceType pt : pos.piece_types())
+            if (!pos.count_in_hand(Them, pt) && (attacks_bb(Us, pt, ksq, pos.pieces()) & safe & pos.drop_region(Them, pt) & ~pos.pieces()))
+                kingDanger += OtherSafeCheck * 500 / (500 + PieceValue[MG][pt]);
+    }
+
     if (pos.check_counting())
         kingDanger += kingDanger * 7 / (3 + pos.checks_remaining(Them));