Update failedHighCnt rule #2063

xoto10 · mcostalba · commit 3a572ffb4840 · 2019-05-15T11:23:07.000+02:00
Treat all threads the same as main thread and increment failedHighCnt on fail highs. This makes the search try again at lower depth. @vondele suggested also changing the reset of failedHighCnt when there is a fail low. Tests including this passed so the branch has been updated to include both changes. failedHighCnt is now handled exactly the same in helper threads and the main thread. Thanks vondele :-) STC @ 5+0.05 th 4 : LLR: 2.94 (-2.94,2.94) [-3.00,1.00] Total: 7769 W: 1704 L: 1557 D: 4508 http://tests.stockfishchess.org/tests/view/5c9f19520ebc5925cfffd2a1 LTC @ 20+0.2 th 8 : LLR: 2.94 (-2.94,2.94) [-3.00,1.00] Total: 37888 W: 5983 L: 5889 D: 26016 http://tests.stockfishchess.org/tests/view/5c9f57d10ebc5925cfffd696 Bench 3824325
diff --git a/src/search.cpp b/src/search.cpp
@@ -404,17 +404,14 @@ void Thread::search() {
                   beta = (alpha + beta) / 2;
                   alpha = std::max(bestValue - delta, -VALUE_INFINITE);
 
+                  failedHighCnt = 0;
                   if (mainThread)
-                  {
-                      failedHighCnt = 0;
                       mainThread->stopOnPonderhit = false;
-                  }
               }
               else if (bestValue >= beta)
               {
                   beta = std::min(bestValue + delta, VALUE_INFINITE);
-                  if (mainThread)
-                      ++failedHighCnt;
+                  ++failedHighCnt;
               }
               else
                   break;

Original file line number	Diff line number	Diff line change
`@@ -404,17 +404,14 @@ void Thread::search() {`
`404`	`404`	`beta = (alpha + beta) / 2;`
`405`	`405`	`alpha = std::max(bestValue - delta, -VALUE_INFINITE);`
`406`	`406`
	`407`	`+ failedHighCnt = 0;`
`407`	`408`	`if (mainThread)`
`408`		`- {`
`409`		`- failedHighCnt = 0;`
`410`	`409`	`mainThread->stopOnPonderhit = false;`
`411`		`- }`
`412`	`410`	`}`
`413`	`411`	`else if (bestValue >= beta)`
`414`	`412`	`{`
`415`	`413`	`beta = std::min(bestValue + delta, VALUE_INFINITE);`
`416`		`- if (mainThread)`
`417`		`- ++failedHighCnt;`
	`414`	`+ ++failedHighCnt;`
`418`	`415`	`}`
`419`	`416`	`else`
`420`	`417`	`break;`