From: Marco Costalba <mcostalba@gmail.com>
Date: Sat, 16 Jan 2016 08:03:56 +0000 (+0100)
Subject: Rewrite time formula
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=356147d99ae6783d79861c32f128a98685024c58;hp=89723339d93c87f52e148080d5b1dc101ee76685

Rewrite time formula

Time management is really too complex, our aim is
to simplify it, but for time being at least rewrite
in an understandable way.

No functional change.
---

diff --git a/src/search.cpp b/src/search.cpp
index a5203b2e..a4bf172a 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -188,7 +188,7 @@ void Search::clear() {
       th->counterMoves.clear();
   }
 
-  Threads.main()->previousMoveScore = VALUE_INFINITE;
+  Threads.main()->previousScore = VALUE_INFINITE;
 }
 
 
@@ -338,7 +338,7 @@ void MainThread::search() {
               bestThread = th;
   }
 
-  previousMoveScore = bestThread->rootMoves[0].score;
+  previousScore = bestThread->rootMoves[0].score;
 
   // Send new PV when needed
   if (bestThread != this)
@@ -538,13 +538,18 @@ void Thread::search() {
               // Stop the search if only one legal move is available, or if all
               // of the available time has been used, or if we matched an easyMove
               // from the previous search and just did a fast verification.
+              const bool F[] = { !mainThread->failedLow,
+                                 bestValue >= mainThread->previousScore };
+
+              int improvingFactor = 640 - 160*F[0] - 126*F[1] - 124*F[0]*F[1];
+
+              bool doEasyMove =   rootMoves[0].pv[0] == easyMove
+                               && mainThread->bestMoveChanges < 0.03
+                               && Time.elapsed() > Time.available() * 25 / 206;
+
               if (   rootMoves.size() == 1
-                  || Time.elapsed() > Time.available() * ( 640  - 160 * !mainThread->failedLow
-                     - 126 * (bestValue >= mainThread->previousMoveScore)
-                     - 124 * (bestValue >= mainThread->previousMoveScore && !mainThread->failedLow))/640
-                  || ( mainThread->easyMovePlayed = ( rootMoves[0].pv[0] == easyMove
-                                                     && mainThread->bestMoveChanges < 0.03
-                                                     && Time.elapsed() > Time.available() * 25/206)))
+                  || Time.elapsed() > Time.available() * improvingFactor / 640
+                  || (mainThread->easyMovePlayed = doEasyMove))
               {
                   // If we are allowed to ponder do not stop the search now but
                   // keep pondering until the GUI sends "ponderhit" or "stop".
@@ -999,11 +1004,10 @@ moves_loop: // When in check search starts from here
                   && cmh[pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
               r += ONE_PLY;
 
-          // Decrease reduction for moves with a good history and
-          // increase reduction for moves with a bad history
-          int rDecrease = (  thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)]
-                           + cmh[pos.piece_on(to_sq(move))][to_sq(move)]) / 14980;
-          r = std::max(DEPTH_ZERO, r - rDecrease * ONE_PLY);
+          // Decrease/increase reduction for moves with a good/bad history
+          int rHist = (  thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)]
+                       + cmh[pos.piece_on(to_sq(move))][to_sq(move)]) / 14980;
+          r = std::max(DEPTH_ZERO, r - rHist * ONE_PLY);
 
           // Decrease reduction for moves that escape a capture. Filter out
           // castling moves, because they are coded as "king captures rook" and
@@ -1472,7 +1476,7 @@ moves_loop: // When in check search starts from here
     int maxScore = -VALUE_INFINITE;
 
     // Choose best move. For each move score we add two terms, both dependent on
-    // weakness. One is deterministic and bigger for weaker levels, and one is 
+    // weakness. One is deterministic and bigger for weaker levels, and one is
     // random. Then we choose the move with the resulting highest score.
     for (size_t i = 0; i < multiPV; ++i)
     {
diff --git a/src/thread.h b/src/thread.h
index 54f4ba06..43ddfbb7 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -80,7 +80,7 @@ struct MainThread : public Thread {
 
   bool easyMovePlayed, failedLow;
   double bestMoveChanges;
-  Value previousMoveScore;
+  Value previousScore;
 };