diff --git a/src/movegen.cpp b/src/movegen.cpp
index c6ba995ed..a95fb03f2 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -25,6 +25,20 @@ namespace Stockfish {
 
 movelist_buf mlb[8] {movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64),movelist_buf(MAX_MOVES,64)};
 
+template<GenType T>
+MoveList<T>::MoveList(const Position& pos)
+{
+    this->mlb = get_thread_mlb(pos);
+    this->moveList = this->mlb->acquire();
+    this->last = generate<T>(pos, this->moveList);
+}
+
+template<GenType T>
+MoveList<T>::~MoveList()
+{
+    this->mlb->release(this->moveList);
+}
+
 namespace {
 
   template<MoveType T>
@@ -504,7 +518,12 @@ template ExtMove* generate<QUIETS>(const Position&, ExtMove*);
 template ExtMove* generate<EVASIONS>(const Position&, ExtMove*);
 template ExtMove* generate<QUIET_CHECKS>(const Position&, ExtMove*);
 template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
-
+template class MoveList<CAPTURES>;
+template class MoveList<QUIETS>;
+template class MoveList<EVASIONS>;
+template class MoveList<QUIET_CHECKS>;
+template class MoveList<NON_EVASIONS>;
+template class MoveList<LEGAL>;
 
 /// generate<LEGAL> generates all the legal moves in the given position
 
diff --git a/src/movegen.h b/src/movegen.h
index c9b49740d..37d781632 100644
--- a/src/movegen.h
+++ b/src/movegen.h
@@ -20,14 +20,13 @@
 #define MOVEGEN_H_INCLUDED
 
 #include <algorithm>
-#include <iostream>
 
 #include "types.h"
 
 namespace Stockfish {
 
 class Position;
-size_t get_thread_id( const Position& pos );
+class movelist_buf;
 
 enum GenType {
   CAPTURES,
@@ -133,18 +132,8 @@ ExtMove* generate(const Position& pos, ExtMove* moveList);
 template<GenType T>
 struct MoveList {
 
-    explicit MoveList(const Position& pos)
-    {
-        this->thread_id = get_thread_id(pos);
-        this->moveList = mlb[thread_id].acquire();
-        this->last = generate<T>(pos, this->moveList);
-    }
-
-    ~MoveList()
-    {
-        mlb[thread_id].release(this->moveList);
-    }
-
+  explicit MoveList(const Position& pos);
+  ~MoveList();
   const ExtMove* begin() const { return moveList; }
   const ExtMove* end() const { return last; }
   size_t size() const { return last - moveList; }
@@ -153,11 +142,13 @@ struct MoveList {
   }
 
 private:
-    size_t thread_id;
+    movelist_buf* mlb;
     ExtMove* last;
     ExtMove* moveList = nullptr;
 };
 
+movelist_buf* get_thread_mlb( const Position& pos );
 } // namespace Stockfish
 
+
 #endif // #ifndef MOVEGEN_H_INCLUDED
diff --git a/src/movepick.cpp b/src/movepick.cpp
index e0146e644..5371671a8 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -69,8 +69,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist
              ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
 
   assert(d > 0);
-  this->thread_id = get_thread_id(pos);
-  this->moves = mlb[thread_id].acquire();
+  this->mlb = get_thread_mlb(pos);
+  this->moves = this->mlb->acquire();
 
   stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
           !(ttm && pos.pseudo_legal(ttm));
@@ -82,8 +82,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist
            : pos(p), mainHistory(mh), gateHistory(dh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) {
 
   assert(d <= 0);
-  this->thread_id = get_thread_id(pos);
-  this->moves = mlb[thread_id].acquire();
+  this->mlb = get_thread_mlb(pos);
+  this->moves = this->mlb->acquire();
 
   stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) +
           !(   ttm
@@ -97,8 +97,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Value th, const GateHistory*
            : pos(p), gateHistory(dh), captureHistory(cph), ttMove(ttm), threshold(th) {
 
   assert(!pos.checkers());
-  this->thread_id = get_thread_id(pos);
-  this->moves = mlb[thread_id].acquire();
+  this->mlb = get_thread_mlb(pos);
+  this->moves = this->mlb->acquire();
 
   stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
                              && pos.pseudo_legal(ttm)
@@ -107,7 +107,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Value th, const GateHistory*
 
 MovePicker::~MovePicker() {
 
-  mlb[thread_id].release(this->moves);
+  this->mlb->release(this->moves);
 }
 
 
diff --git a/src/movepick.h b/src/movepick.h
index e51ca3236..2569b02a6 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -162,7 +162,7 @@ class MovePicker {
   Value threshold;
   Depth depth;
   int ply;
-  size_t thread_id;
+  movelist_buf* mlb;
   ExtMove* moves;
 };
 
diff --git a/src/position.cpp b/src/position.cpp
index ec0764bbc..fab21d9af 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -148,7 +148,7 @@ Move cuckooMove[8192];
 
 size_t get_thread_id( const Position& pos )
 {
-	return pos.this_thread()->id();
+	return pos.thread_id;
 }
 
 /// Position::init() initializes at startup the various arrays used to compute hash keys
@@ -533,6 +533,16 @@ Position& Position::set(const Variant* v, const string& fenStr, bool isChess960,
   chess960 = isChess960 || v->chess960;
   tsumeMode = Options["TsumeMode"];
   thisThread = th;
+  if ( th )
+  {
+    this->thread_id = th->id();
+    this->mlb = &mlb[this->thread_id];
+  }
+  else
+  {
+    this->thread_id = 0;
+    this->mlb = nullptr;
+  }
   set_state(st);
 
   assert(pos_is_ok());
diff --git a/src/position.h b/src/position.h
index d0d20509a..e8e4977c8 100644
--- a/src/position.h
+++ b/src/position.h
@@ -36,6 +36,11 @@
 
 namespace Stockfish {
 
+class movelist_buf;
+
+size_t get_thread_id( const Position& pos );
+movelist_buf* get_thread_mlb( const Position& pos );
+
 /// StateInfo struct stores information needed to restore a Position object to
 /// its previous state when we retract a move. Whenever a move is made on the
 /// board (by calling Position::do_move), a StateInfo object must be passed.
@@ -339,6 +344,11 @@ class Position {
   void put_piece(Piece pc, Square s, bool isPromoted = false, Piece unpromotedPc = NO_PIECE);
   void remove_piece(Square s);
 
+  size_t thread_id;
+  movelist_buf* mlb;
+
+  movelist_buf* get_mlb() const;
+
 private:
   // Initialization helpers (used while setting up a position)
   void set_castling_right(Color c, Square rfrom);
@@ -1416,8 +1426,6 @@ inline const std::string Position::piece_to_partner() const {
   return std::string(1, piece_to_char()[piece]);
 }
 
-size_t get_thread_id( const Position& pos );
-
 inline Thread* Position::this_thread() const {
   return thisThread;
 }
@@ -1569,6 +1577,21 @@ inline bool Position::can_drop(Color c, PieceType pt) const {
   return variant()->freeDrops || count_in_hand(c, pt) > 0;
 }
 
+inline void set_thread_mlb(Position& pos)
+{
+	pos.mlb = &mlb[pos.thread_id];
+}
+
+inline movelist_buf* get_thread_mlb(const Position& pos)
+{
+	return &mlb[pos.thread_id];
+}
+
+inline movelist_buf* Position::get_mlb() const
+{
+	return &mlb[this->thread_id];
+}
+
 } // namespace Stockfish
 
 #endif // #ifndef POSITION_H_INCLUDED
diff --git a/src/thread.cpp b/src/thread.cpp
index 32aaf58ea..8543b8592 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -30,6 +30,8 @@
 
 namespace Stockfish {
 
+size_t TH_STACK_SIZE = 8 * 1024 * 1024; // Default size.
+
 ThreadPool Threads; // Global object
 
 
diff --git a/src/thread.h b/src/thread.h
index 464be79ed..9fd4f5b2c 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -34,6 +34,8 @@
 
 namespace Stockfish {
 
+extern size_t TH_STACK_SIZE;
+
 /// Thread class keeps together all the thread-related stuff. We use
 /// per-thread pawn and material hash tables so that once we get a
 /// pointer to an entry its life time is unlimited and we don't have
diff --git a/src/thread_win32_osx.h b/src/thread_win32_osx.h
index e2adc76d5..fe44ab2c5 100644
--- a/src/thread_win32_osx.h
+++ b/src/thread_win32_osx.h
@@ -33,7 +33,7 @@
 
 namespace Stockfish {
 
-static const size_t TH_STACK_SIZE = 8 * 1024 * 1024;
+extern size_t TH_STACK_SIZE;
 
 template <class T, class P = std::pair<T*, void(T::*)()>>
 void* start_routine(void* ptr)
diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index 0326e047f..8d8e9f30a 100644
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -63,6 +63,22 @@ 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_tb_path(const Option& o) { Tablebases::init(o); }
+void on_max_moves(const Option& o)
+{
+	/*
+    if      (o == "256")  max_moves_index = 0;
+    else if (o == "512")  max_moves_index = 1;
+    else if (o == "1024") max_moves_index = 2;
+    else if (o == "2048") max_moves_index = 3;
+    else if (o == "4096") max_moves_index = 4;
+    else if (o == "8192") max_moves_index = 5;
+    else                  max_moves_index = 3;
+    //*/
+}
+
+#if defined(__APPLE__) || defined(__MINGW32__) || defined(__MINGW64__) || defined(USE_PTHREADS)
+void on_stack_size(const Option& o) { TH_STACK_SIZE=size_t(o)*1024*1024; }
+#endif
 
 void on_use_NNUE(const Option& ) { Eval::NNUE::init(); }
 void on_eval_file(const Option& ) { Eval::NNUE::init(); }
@@ -209,6 +225,10 @@ void init(OptionsMap& o) {
   o["TsumeMode"]             << Option(false);
   o["VariantPath"]           << Option("<empty>", on_variant_path);
   o["usemillisec"]           << Option(true); // time unit for UCCI
+  o["MaxMoves"]              << Option("1024", {"256", "512", "1024", "2048", "4096", "8192", "16384"}, on_max_moves);
+#if defined(__APPLE__) || defined(__MINGW32__) || defined(__MINGW64__) || defined(USE_PTHREADS)
+  o["StackSize"]             << Option(8, 1, 64, on_stack_size);
+#endif
 }