Merge pull request official-stockfish#620 from IIvec/master

IIvec · web-flow · commit 0f4f6f8bd7da · 2018-01-13T17:36:22.000+01:00
New master
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
@@ -220,7 +220,6 @@ namespace {
   const Score WeakQueen             = S( 50, 10);
   const Score CloseEnemies          = S(  7,  0);
   const Score PawnlessFlank         = S( 20, 80);
-  const Score ThreatByHangingPawn   = S( 71, 61);
   const Score ThreatBySafePawn      = S(192,175);
   const Score ThreatByRank          = S( 16,  3);
   const Score Hanging               = S( 48, 27);
@@ -489,7 +488,11 @@ namespace {
 
         // Transform the kingDanger units into a Score, and substract it from the evaluation
         if (kingDanger > 0)
+        {
+            int mobilityDanger = mg_value(mobility[Them] - mobility[Us]);
+            kingDanger = std::max(0, kingDanger + mobilityDanger);
             score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
+        }
     }
 
     // King tropism: firstly, find squares that opponent attacks in our king flank
@@ -543,9 +546,6 @@ namespace {
         safeThreats = (shift<Right>(b) | shift<Left>(b)) & weak;
 
         score += ThreatBySafePawn * popcount(safeThreats);
-
-        if (weak ^ safeThreats)
-            score += ThreatByHangingPawn;
     }
 
     // Squares strongly protected by the opponent, either because they attack the
diff --git a/src/search.cpp b/src/search.cpp
@@ -688,7 +688,7 @@ namespace {
     if (   !PvNode
         &&  eval >= beta
         &&  ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
-        && (ss->ply >= thisThread->nmp_ply || ss->ply % 2 == thisThread->pair)
+        && (ss->ply >= thisThread->nmp_ply || ss->ply % 2 != thisThread->nmp_odd)
         &&  abs(eval) < 2 * VALUE_KNOWN_WIN
         &&  pos.non_pawn_material(~pos.side_to_move())
         && !(depth > 4 * ONE_PLY && (MoveList<LEGAL, KING>(pos).size() < 1 || MoveList<LEGAL>(pos).size() < 6)))
@@ -713,21 +713,18 @@ namespace {
             if (nullValue >= VALUE_MATE_IN_MAX_PLY)
                 nullValue = beta;
 
-            if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN)
+            if (abs(beta) < VALUE_KNOWN_WIN && (depth < 12 * ONE_PLY || thisThread->nmp_ply))
                 return nullValue;
 
             // Do verification search at high depths
-            R += ONE_PLY;
             // disable null move pruning for side to move for the first part of the remaining search tree
-            int nmp_ply = thisThread->nmp_ply;
-            int pair = thisThread->pair;
             thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4;
-            thisThread->pair = (ss->ply % 2) == 0;
+            thisThread->nmp_odd = ss->ply % 2;
 
             Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta)
                                         :  search<NonPV>(pos, ss, beta-1, beta, depth-R, false, true);
-            thisThread->pair = pair;
-            thisThread->nmp_ply = nmp_ply;
+
+            thisThread->nmp_odd = thisThread->nmp_ply = 0;
 
             if (v >= beta)
                 return nullValue;
@@ -1519,7 +1516,7 @@ namespace {
     if (Threads.ponder)
         return;
 
-    if (   (Limits.use_time_management() && elapsed > Time.maximum())
+    if (   (Limits.use_time_management() && elapsed > Time.maximum() - 10)
         || (Limits.movetime && elapsed >= Limits.movetime)
         || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes))
             Threads.stop = true;
diff --git a/src/thread.cpp b/src/thread.cpp
@@ -187,12 +187,10 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
 
   for (Thread* th : *this)
   {
-      th->nodes = th->tbHits = 0;
+      th->nodes = th->tbHits = th->nmp_ply = th->nmp_odd = 0;
       th->rootDepth = th->completedDepth = DEPTH_ZERO;
       th->rootMoves = rootMoves;
       th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
-      th->nmp_ply = 0;
-      th->pair = -1;
   }
 
   setupStates->back() = tmp;
diff --git a/src/thread.h b/src/thread.h
@@ -61,7 +61,7 @@ class Thread {
   Material::Table materialTable;
   Endgames endgames;
   size_t PVIdx;
-  int selDepth, nmp_ply, pair;
+  int selDepth, nmp_ply, nmp_odd;
   std::atomic<uint64_t> nodes, tbHits;
 
   Position rootPos;
diff --git a/src/timeman.cpp b/src/timeman.cpp
@@ -19,6 +19,8 @@
 */
 
 #include <algorithm>
+#include <cfloat>
+#include <cmath>
 
 #include "search.h"
 #include "timeman.h"
@@ -30,46 +32,41 @@ namespace {
 
   enum TimeType { OptimumTime, MaxTime };
 
-  int remaining(int myTime, int myInc, int moveOverhead, int movesToGo,
-                int moveNum, bool ponder, TimeType type) {
+  const int MoveHorizon   = 50;   // Plan time management at most this many moves ahead
+  const double MaxRatio   = 7.09; // When in trouble, we can step over reserved time with this ratio
+  const double StealRatio = 0.35; // However we must not steal time from remaining moves over this ratio
 
-    if (myTime <= 0)
-        return 0;
 
-    double ratio; // Which ratio of myTime we are going to use
+  // move_importance() is a skew-logistic function based on naive statistical
+  // analysis of "how many games are still undecided after n half-moves". Game
+  // is considered "undecided" as long as neither side has >275cp advantage.
+  // Data was extracted from the CCRL game database with some simple filtering criteria.
 
-    // Usage of increment follows quadratic distribution with the maximum at move 25
-    double inc = myInc * std::max(55.0, 120 - 0.12 * (moveNum - 25) * (moveNum - 25));
+  double move_importance(int ply) {
 
-    // In moves-to-go we distribute time according to a quadratic function with
-    // the maximum around move 20 for 40 moves in y time case.
-    if (movesToGo)
-    {
-        ratio = (type == OptimumTime ? 1.0 : 6.0) / std::min(50, movesToGo);
+    const double XScale = 7.64;
+    const double XShift = 58.4;
+    const double Skew   = 0.183;
 
-        if (moveNum <= 40)
-            ratio *= 1.1 - 0.001 * (moveNum - 20) * (moveNum - 20);
-        else
-            ratio *= 1.5;
+    return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
+  }
+
+  template<TimeType T>
+  int remaining(int myTime, int movesToGo, int ply, int slowMover) {
 
-        if (movesToGo > 1)
-            ratio = std::min(0.75, ratio);
+    const double TMaxRatio   = (T == OptimumTime ? 1 : MaxRatio);
+    const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
 
-        ratio *= 1 + inc / (myTime * 8.5);
-    }
-    // Otherwise we increase usage of remaining time as the game goes on
-    else
-    {
-        double k = 1 + 20 * moveNum / (500.0 + moveNum);
-        ratio = (type == OptimumTime ? 0.017 : 0.07) * (k + inc / myTime);
-    }
+    double moveImportance = (move_importance(ply) * slowMover) / 100;
+    double otherMovesImportance = 0;
 
-    int time = int(std::min(1.0, ratio) * std::max(0, myTime - moveOverhead));
+    for (int i = 1; i < movesToGo; ++i)
+        otherMovesImportance += move_importance(ply + 2 * i);
 
-    if (type == OptimumTime && ponder)
-        time = 5 * time / 4;
+    double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
+    double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
 
-    return time;
+    return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast
   }
 
 } // namespace
@@ -84,11 +81,12 @@ namespace {
 ///  inc >  0 && movestogo == 0 means: x basetime + z increment
 ///  inc >  0 && movestogo != 0 means: x moves in y minutes + z increment
 
-void TimeManagement::init(Search::LimitsType& limits, Color us, int ply)
-{
-  int moveOverhead = Options["Move Overhead"];
-  int npmsec       = Options["nodestime"];
-  bool ponder      = Options["Ponder"];
+void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
+
+  int minThinkingTime = Options["Minimum Thinking Time"];
+  int moveOverhead    = Options["Move Overhead"];
+  int slowMover       = Options["Slow Mover"];
+  int npmsec          = Options["nodestime"];
 
   // If we have to play in 'nodes as time' mode, then convert from time
   // to nodes, and use resulting values in time management formulas.
@@ -105,11 +103,30 @@ void TimeManagement::init(Search::LimitsType& limits, Color us, int ply)
       limits.npmsec = npmsec;
   }
 
-  int moveNum = (ply + 1) / 2;
-
   startTime = limits.startTime;
-  optimumTime = remaining(limits.time[us], limits.inc[us], moveOverhead,
-                          limits.movestogo, moveNum, ponder, OptimumTime);
-  maximumTime = remaining(limits.time[us], limits.inc[us], moveOverhead,
-                          limits.movestogo, moveNum, ponder, MaxTime);
+  optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime);
+
+  const int MaxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
+
+  // We calculate optimum time usage for different hypothetical "moves to go"-values
+  // and choose the minimum of calculated search time values. Usually the greatest
+  // hypMTG gives the minimum values.
+  for (int hypMTG = 1; hypMTG <= MaxMTG; ++hypMTG)
+  {
+      // Calculate thinking time for hypothetical "moves to go"-value
+      int hypMyTime =  limits.time[us]
+                     + limits.inc[us] * (hypMTG - 1)
+                     - moveOverhead * (2 + std::min(hypMTG, 40));
+
+      hypMyTime = std::max(hypMyTime, 0);
+
+      int t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
+      int t2 = minThinkingTime + remaining<MaxTime    >(hypMyTime, hypMTG, ply, slowMover);
+
+      optimumTime = std::min(t1, optimumTime);
+      maximumTime = std::min(t2, maximumTime);
+  }
+
+  if (Options["Ponder"])
+      optimumTime += optimumTime / 4;
 }
diff --git a/src/ucioption.cpp b/src/ucioption.cpp
@@ -67,7 +67,9 @@ void init(OptionsMap& o) {
   o["Ponder"]                << Option(false);
   o["MultiPV"]               << Option(1, 1, 500);
   o["Skill Level"]           << Option(20, 0, 20);
-  o["Move Overhead"]         << Option(100, 0, 5000);
+  o["Move Overhead"]         << Option(30, 0, 5000);
+  o["Minimum Thinking Time"] << Option(20, 0, 5000);
+  o["Slow Mover"]            << Option(89, 10, 1000);
   o["nodestime"]             << Option(0, 0, 10000);
   o["Study"]                 << Option(false);
   o["UCI_Chess960"]          << Option(false);

Original file line number	Diff line number	Diff line change
`@@ -187,12 +187,10 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,`
`187`	`187`
`188`	`188`	`for (Thread* th : *this)`
`189`	`189`	`{`
`190`		`- th->nodes = th->tbHits = 0;`
	`190`	`+ th->nodes = th->tbHits = th->nmp_ply = th->nmp_odd = 0;`
`191`	`191`	`th->rootDepth = th->completedDepth = DEPTH_ZERO;`
`192`	`192`	`th->rootMoves = rootMoves;`
`193`	`193`	`th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);`
`194`		`- th->nmp_ply = 0;`
`195`		`- th->pair = -1;`
`196`	`194`	`}`
`197`	`195`
`198`	`196`	`setupStates->back() = tmp;`