Fix bug with "excludedMove" for probcut

MJZ1977 · snicolet · commit 10bb2e6cdb5c · 2018-08-29T02:28:09.000+02:00
Bugfix: "excludedMove" has to be skipped in the probcut loop too. If it is not skipped, the probcut can exit quickly with a wrong return value corresponding to the excluded move. See the following forum thread for a discussion: https://groups.google.com/forum/?fromgroups=#!topic/fishcooking/GGithf_VwSU STC : LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 17130 W: 3747 L: 3617 D: 9766 http://tests.stockfishchess.org/tests/view/5b8460c40ebc5902bdbb999a LTC : LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 12387 W: 2064 L: 1930 D: 8393 http://tests.stockfishchess.org/tests/view/5b8466f90ebc5902bdbb9a21 To go further : it can be perhaps useful to tune the singular extension search parameters. Closes #1754 Bench: 4308541
diff --git a/src/search.cpp b/src/search.cpp
@@ -815,7 +815,7 @@ namespace {
 
         while (  (move = mp.next_move()) != MOVE_NONE
                && probCutCount < 3)
-            if (pos.legal(move))
+            if (move != excludedMove && pos.legal(move))
             {
                 probCutCount++;
 

Original file line number	Diff line number	Diff line change
`@@ -815,7 +815,7 @@ namespace {`
`815`	`815`
`816`	`816`	`while ( (move = mp.next_move()) != MOVE_NONE`
`817`	`817`	`&& probCutCount < 3)`
`818`		`- if (pos.legal(move))`
	`818`	`+ if (move != excludedMove && pos.legal(move))`
`819`	`819`	`{`
`820`	`820`	`probCutCount++;`
`821`	`821`