From: xoto10 <buylow001@gmail.com>
Date: Sun, 31 Mar 2019 15:33:32 +0000 (+0100)
Subject: Update failedHighCnt rule #2063
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=3a572ffb4840bfea3c587c9c81a0008515f02a32;hp=02708a4a1153d59c058f8056bc31713322130392

Update failedHighCnt rule #2063

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
index 0e9674a0..fdef1400 100644
--- 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;