5.3.0 No LMR for passed pawns

Oliver Brausch · Oliver Brausch · commit ff0d4fbf4000 · 2020-08-16T00:49:43.000+02:00
diff --git a/src/Readme.txt b/src/Readme.txt
@@ -1,6 +1,6 @@
-OliThink5 (c) Oliver Brausch 09.Jan.2010, ob112@web.de, http://home.arcor.de/dreamlike
+OliThink5 (c) Oliver Brausch 28.Jan.2010, ob112@web.de, http://home.arcor.de/dreamlike
 
-Version: 5.2.9
+Version: 5.3.0
 Protocol: Winboard 2
 HashSize: 48mb
 Ponder: Yes
@@ -13,6 +13,9 @@ LinesOfCode: 1670
 Stability: 100%
 Strength: slightly weaker than Glaurung/Crafty
 
+v5.3.0: changes since 5.2.9:
+No LMR for passed pawns
+
 v5.2.9: changes since 5.2.8:
 More flexible reducing in Null Move Pruning
 
diff --git a/src/olithink.c b/src/olithink.c
@@ -1,5 +1,5 @@
-/* OliThink5 (c) Oliver Brausch 09.Jan.2010, ob112@web.de, http://home.arcor.de/dreamlike */
-#define VER "5.2.9"
+/* OliThink5 (c) Oliver Brausch 25.Jan.2010, ob112@web.de, http://home.arcor.de/dreamlike */
+#define VER "5.3.0"
 #define _CRT_SECURE_NO_DEPRECATE
 #include <stdio.h>
 #include <stdlib.h>
@@ -1364,7 +1364,7 @@ int search(u64 ch, int c, int d, int ply, int alpha, int beta, int pvnode, int n
 		if (nch) ext++; // Check Extension
 		else if (d >= 3 && i >= 4 && !pvnode) { //LMR
 			if (CAP(m) || PROM(m)); //Don't reduce Captures and Promotions
-			else if (PIECE(m) == PAWN && ((TO(m) + 16) & 48) < 32); //Don't reduce pawns moving to 7th rank
+			else if (PIECE(m) == PAWN && !(pawnfree[TO(m) + (c << 6)] & pieceb[PAWN] & colorb[c^1])); //Don't reduce free pawns
 			else ext--;
 	        }
 
