Merge branch 'random_eval_perturb_2' of github.com:Sopel97/Stockfish …

…into HalfKAv2_hm

src/evaluate.cpp

@@ -23,6 +23,7 @@
 #include <fstream>
 #include <iomanip>
 #include <sstream>
+#include <random>
 #include <iostream>
 #include <streambuf>
 #include <vector>
@@ -63,6 +64,8 @@ namespace Eval {
   bool useNNUE;
   string eval_file_loaded = "None";
 
+  int NNUE::RandomEvalPerturb = 0;
+
   /// NNUE::init() tries to load a NNUE network at startup time, or when the engine
   /// receives a UCI command "setoption name EvalFile value nn-[a-z0-9]{12}.nnue"
   /// The name of the NNUE network is always retrieved from the EvalFile option.
@@ -1081,6 +1084,10 @@ namespace {
 
 Value Eval::evaluate(const Position& pos) {
 
+  static thread_local std::mt19937_64 tls_rng = [](){
+    return std::mt19937_64(std::time(0));
+  }();
+
   Value v;
 
   if (!Eval::useNNUE)
@@ -1107,6 +1114,7 @@ Value Eval::evaluate(const Position& pos) {
       int r50 = pos.rule50_count();
       Value psq = Value(abs(eg_value(pos.psq_score())));
       bool classical = psq * 5 > (850 + pos.non_pawn_material() / 64) * (5 + r50);
+      classical = false;
 
       v = classical ? Evaluation<NO_TRACE>(pos).value()  // classical
                     : adjusted_NNUE();                   // NNUE
@@ -1115,6 +1123,12 @@ Value Eval::evaluate(const Position& pos) {
   // Damp down the evaluation linearly when shuffling
   v = v * (100 - pos.rule50_count()) / 100;
 
+  std::normal_distribution<float> d(0.0, RookValueEg);
+  float r = d(tls_rng);
+  r = std::clamp<float>(r, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
+
+  v = (NNUE::RandomEvalPerturb * Value(r) + (100 - NNUE::RandomEvalPerturb) * v) / 100;
+
   // Guarantee evaluation does not hit the tablebase range
   v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
 

src/evaluate.h

@@ -43,6 +43,8 @@ namespace Eval {
 
   namespace NNUE {
 
+    extern int RandomEvalPerturb;
+
     std::string trace(Position& pos);
     Value evaluate(const Position& pos, bool adjusted = false);
 

src/ucioption.cpp

@@ -42,6 +42,7 @@ void on_clear_hash(const Option&) { Search::clear(); }
 void on_hash_size(const Option& o) { TT.resize(size_t(o)); }
 void on_logger(const Option& o) { start_logger(o); }
 void on_threads(const Option& o) { Threads.set(size_t(o)); }
+void on_eval_perturb(const Option& o) { Eval::NNUE::RandomEvalPerturb = o; }
 void on_tb_path(const Option& o) { Tablebases::init(o); }
 void on_use_NNUE(const Option& ) { Eval::NNUE::init(); }
 void on_eval_file(const Option& ) { Eval::NNUE::init(); }
@@ -62,6 +63,7 @@ void init(OptionsMap& o) {
 
   o["Debug Log File"]        << Option("", on_logger);
   o["Threads"]               << Option(1, 1, 512, on_threads);
+  o["RandomEvalPerturb"]     << Option(0, 0, 100, on_eval_perturb);
   o["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
   o["Clear Hash"]            << Option(on_clear_hash);
   o["Ponder"]                << Option(false);