diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index abf5e34c..45f63acb 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -65,20 +65,20 @@ Value Evaluation<T>::value()
 {
     Value value = VALUE_ZERO;
 
-    int nPiecesInHandDiff;
-    int nPiecesOnBoardDiff;
-    int nPiecesNeedRemove;
+    int pieceInHandDiffCount;
+    int pieceOnBoardDiffCount;
+    int pieceToRemoveCount;
 
     switch (pos.get_phase()) {
     case Phase::ready:
         break;
 
     case Phase::placing:
-        nPiecesInHandDiff = pos.n_pieces_in_hand(BLACK) - pos.n_pieces_in_hand(WHITE);
-        value += nPiecesInHandDiff * VALUE_EACH_PIECE_INHAND;
+        pieceInHandDiffCount = pos.piece_in_hand_count(BLACK) - pos.piece_in_hand_count(WHITE);
+        value += pieceInHandDiffCount * VALUE_EACH_PIECE_INHAND;
 
-        nPiecesOnBoardDiff = pos.n_pieces_on_board(BLACK) - pos.n_pieces_on_board(WHITE);
-        value += nPiecesOnBoardDiff * VALUE_EACH_PIECE_ONBOARD;
+        pieceOnBoardDiffCount = pos.piece_on_board_count(BLACK) - pos.piece_on_board_count(WHITE);
+        value += pieceOnBoardDiffCount * VALUE_EACH_PIECE_ONBOARD;
 
         switch (pos.get_action()) {
         case Action::select:
@@ -86,9 +86,9 @@ Value Evaluation<T>::value()
             break;
 
         case Action::remove:
-            nPiecesNeedRemove = (pos.side_to_move() == BLACK) ?
-                pos.n_pieces_to_remove() : -(pos.n_pieces_to_remove());
-            value += nPiecesNeedRemove * VALUE_EACH_PIECE_PLACING_NEEDREMOVE;
+            pieceToRemoveCount = (pos.side_to_move() == BLACK) ?
+                pos.piece_to_remove_count() : -(pos.piece_to_remove_count());
+            value += pieceToRemoveCount * VALUE_EACH_PIECE_PLACING_NEEDREMOVE;
             break;
         default:
             break;
@@ -97,11 +97,11 @@ Value Evaluation<T>::value()
         break;
 
     case Phase::moving:
-        value = pos.n_pieces_on_board(BLACK) * VALUE_EACH_PIECE_ONBOARD -
-            pos.n_pieces_on_board(WHITE) * VALUE_EACH_PIECE_ONBOARD;
+        value = pos.piece_on_board_count(BLACK) * VALUE_EACH_PIECE_ONBOARD -
+            pos.piece_on_board_count(WHITE) * VALUE_EACH_PIECE_ONBOARD;
 
 #ifdef EVALUATE_MOBILITY
-        value += pos.get_mobility_diff(position->turn, position->nPiecesInHand[BLACK], position->nPiecesInHand[WHITE], false) * 10;
+        value += pos.get_mobility_diff(position->turn, position->pieceInHandCount[BLACK], position->pieceInHandCount[WHITE], false) * 10;
 #endif  /* EVALUATE_MOBILITY */
 
         switch (pos.get_action()) {
@@ -110,9 +110,9 @@ Value Evaluation<T>::value()
             break;
 
         case Action::remove:
-            nPiecesNeedRemove = (pos.side_to_move() == BLACK) ?
-                pos.n_pieces_to_remove() : -(pos.n_pieces_to_remove());
-            value += nPiecesNeedRemove * VALUE_EACH_PIECE_MOVING_NEEDREMOVE;
+            pieceToRemoveCount = (pos.side_to_move() == BLACK) ?
+                pos.piece_to_remove_count() : -(pos.piece_to_remove_count());
+            value += pieceToRemoveCount * VALUE_EACH_PIECE_MOVING_NEEDREMOVE;
             break;
         default:
             break;
@@ -121,7 +121,7 @@ Value Evaluation<T>::value()
         break;
 
     case Phase::gameOver:
-        if (pos.n_pieces_on_board(BLACK) + pos.n_pieces_on_board(WHITE) >= EFFECTIVE_SQUARE_NB) {
+        if (pos.piece_on_board_count(BLACK) + pos.piece_on_board_count(WHITE) >= EFFECTIVE_SQUARE_NB) {
             if (rule.isBlackLoseButNotDrawWhenBoardFull) {
                 value -= VALUE_MATE;
             } else {
@@ -134,9 +134,9 @@ Value Evaluation<T>::value()
             value += delta;
         }
 
-        else if (pos.n_pieces_on_board(BLACK) < rule.nPiecesAtLeast) {
+        else if (pos.piece_on_board_count(BLACK) < rule.piecesAtLeastCount) {
             value -= VALUE_MATE;
-        } else if (pos.n_pieces_on_board(WHITE) < rule.nPiecesAtLeast) {
+        } else if (pos.piece_on_board_count(WHITE) < rule.piecesAtLeastCount) {
             value += VALUE_MATE;
         }
 
diff --git a/src/movegen.cpp b/src/movegen.cpp
index 1a8c1a26..370476a9 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -60,7 +60,7 @@ ExtMove *generate<MOVE>(Position &pos, ExtMove *moveList)
             continue;
         }
 
-        if (pos.n_pieces_on_board(pos.side_to_move()) > rule.nPiecesAtLeast ||
+        if (pos.piece_on_board_count(pos.side_to_move()) > rule.piecesAtLeastCount ||
             !rule.flyingAllowed) {
             for (auto direction = MD_BEGIN; direction < MD_NB; ++direction) {
                 to = static_cast<Square>(MoveList<LEGAL>::adjacentSquares[from][direction]);
diff --git a/src/position.cpp b/src/position.cpp
index 35977611..2ecb8da4 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -273,9 +273,9 @@ Position &Position::set(const string &fenStr, Thread *th)
     
     // 5. Black on board / Black in hand / White on board / White in hand / need to remove
     ss >> std::skipws
-        >> nPiecesOnBoard[BLACK] >> nPiecesInHand[BLACK]
-        >> nPiecesOnBoard[WHITE] >> nPiecesInHand[WHITE]
-        >> nPiecesNeedRemove;
+        >> pieceOnBoardCount[BLACK] >> pieceInHandCount[BLACK]
+        >> pieceOnBoardCount[WHITE] >> pieceInHandCount[WHITE]
+        >> pieceToRemoveCount;
 
 
     // 6-7. Halfmove clock and fullmove number
@@ -360,9 +360,9 @@ const string Position::fen() const
 
     ss << " ";
 
-    ss << nPiecesOnBoard[BLACK] << " " << nPiecesInHand[BLACK] << " "
-        << nPiecesOnBoard[WHITE] << " " << nPiecesInHand[WHITE] << " "
-        << nPiecesNeedRemove << " ";
+    ss << pieceOnBoardCount[BLACK] << " " << pieceInHandCount[BLACK] << " "
+        << pieceOnBoardCount[WHITE] << " " << pieceInHandCount[WHITE] << " "
+        << pieceToRemoveCount << " ";
 
     ss << st.rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2;
 
@@ -535,9 +535,9 @@ void Position::undo_move(Move m)
     }
 
     // TODO: Adjust
-    //int nPiecesInHand[COLOR_NB]{ 0 };
-    //int nPiecesOnBoard[COLOR_NB]{ 0 };
-    //int nPiecesNeedRemove{ 0 };
+    //int pieceInHandCount[COLOR_NB]{ 0 };
+    //int pieceOnBoardCount[COLOR_NB]{ 0 };
+    //int pieceToRemoveCount{ 0 };
 
     // TODO End
 
@@ -666,17 +666,17 @@ bool Position::pos_is_ok() const
 
 ///////////////////////////////////////////////////////////////////////////////
 
-int Position::n_pieces_on_board_count()
+int Position::piece_on_board_count_count()
 {
-    nPiecesOnBoard[BLACK] = nPiecesOnBoard[WHITE] = 0;
+    pieceOnBoardCount[BLACK] = pieceOnBoardCount[WHITE] = 0;
 
     for (int f = 1; f < FILE_NB + 2; f++) {
         for (int r = 0; r < RANK_NB; r++) {
             Square s = static_cast<Square>(f * RANK_NB + r);
             if (board[s] & B_STONE) {
-                nPiecesOnBoard[BLACK]++;
+                pieceOnBoardCount[BLACK]++;
             } else if (board[s] & W_STONE) {
-                nPiecesOnBoard[WHITE]++;
+                pieceOnBoardCount[WHITE]++;
             }
 #if 0
             else if (board[s] & BAN_STONE) {
@@ -685,20 +685,20 @@ int Position::n_pieces_on_board_count()
         }
     }
 
-    if (nPiecesOnBoard[BLACK] > rule.nTotalPiecesEachSide ||
-        nPiecesOnBoard[WHITE] > rule.nTotalPiecesEachSide) {
+    if (pieceOnBoardCount[BLACK] > rule.nTotalPiecesEachSide ||
+        pieceOnBoardCount[WHITE] > rule.nTotalPiecesEachSide) {
         return -1;
     }
 
-    return nPiecesOnBoard[BLACK] + nPiecesOnBoard[WHITE];
+    return pieceOnBoardCount[BLACK] + pieceOnBoardCount[WHITE];
 }
 
-int Position::get_n_pieces_in_hand()
+int Position::get_piece_in_hand_count()
 {
-    nPiecesInHand[BLACK] = rule.nTotalPiecesEachSide - nPiecesOnBoard[BLACK];
-    nPiecesInHand[WHITE] = rule.nTotalPiecesEachSide - nPiecesOnBoard[WHITE];
+    pieceInHandCount[BLACK] = rule.nTotalPiecesEachSide - pieceOnBoardCount[BLACK];
+    pieceInHandCount[WHITE] = rule.nTotalPiecesEachSide - pieceOnBoardCount[WHITE];
 
-    return nPiecesInHand[BLACK] + nPiecesInHand[WHITE];
+    return pieceInHandCount[BLACK] + pieceInHandCount[WHITE];
 }
 
 #ifdef THREEFOLD_REPETITION
@@ -726,9 +726,9 @@ bool Position::reset()
     memset(byTypeBB, 0, sizeof(byTypeBB));
     memset(byColorBB, 0, sizeof(byColorBB));
 
-    nPiecesOnBoard[BLACK] = nPiecesOnBoard[WHITE] = 0;
-    nPiecesInHand[BLACK] = nPiecesInHand[WHITE] = rule.nTotalPiecesEachSide;
-    nPiecesNeedRemove = 0;
+    pieceOnBoardCount[BLACK] = pieceOnBoardCount[WHITE] = 0;
+    pieceInHandCount[BLACK] = pieceInHandCount[WHITE] = rule.nTotalPiecesEachSide;
+    pieceToRemoveCount = 0;
     millListSize = 0;
 
     MoveList<LEGAL>::create();
@@ -792,9 +792,9 @@ bool Position::put_piece(Square s, bool updateCmdlist)
     }
 
     if (phase == Phase::placing) {
-        piece = (Piece)((0x01 | make_piece(sideToMove)) + rule.nTotalPiecesEachSide - nPiecesInHand[us]);
-        nPiecesInHand[us]--;
-        nPiecesOnBoard[us]++;
+        piece = (Piece)((0x01 | make_piece(sideToMove)) + rule.nTotalPiecesEachSide - pieceInHandCount[us]);
+        pieceInHandCount[us]--;
+        pieceOnBoardCount[us]++;
 
         Piece pc = board[s] = piece;
         byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
@@ -811,9 +811,9 @@ bool Position::put_piece(Square s, bool updateCmdlist)
         int n = add_mills(currentSquare);
 
         if (n == 0) {
-            assert(nPiecesInHand[BLACK] >= 0 && nPiecesInHand[WHITE] >= 0);     
+            assert(pieceInHandCount[BLACK] >= 0 && pieceInHandCount[WHITE] >= 0);     
 
-            if (nPiecesInHand[BLACK] == 0 && nPiecesInHand[WHITE] == 0) {
+            if (pieceInHandCount[BLACK] == 0 && pieceInHandCount[WHITE] == 0) {
                 if (check_if_game_is_over()) {
                     return true;
                 }
@@ -836,7 +836,7 @@ bool Position::put_piece(Square s, bool updateCmdlist)
                 change_side_to_move();
             }
         } else {
-            nPiecesNeedRemove = rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
+            pieceToRemoveCount = rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
             update_key_misc();
             action = Action::remove;
         } 
@@ -848,7 +848,7 @@ bool Position::put_piece(Square s, bool updateCmdlist)
         }
 
         // if illegal
-        if (nPiecesOnBoard[sideToMove] > rule.nPiecesAtLeast ||
+        if (pieceOnBoardCount[sideToMove] > rule.piecesAtLeastCount ||
             !rule.flyingAllowed) {
             if ((square_bb(s) & MoveList<LEGAL>::adjacentSquaresBB[currentSquare]) == 0) {
                 return false;
@@ -890,7 +890,7 @@ bool Position::put_piece(Square s, bool updateCmdlist)
                 return true;
             }
         } else {
-            nPiecesNeedRemove = rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
+            pieceToRemoveCount = rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
             update_key_misc();
             action = Action::remove;
         }
@@ -909,7 +909,7 @@ bool Position::remove_piece(Square s, bool updateCmdlist)
     if (action != Action::remove)
         return false;
 
-    if (nPiecesNeedRemove <= 0)
+    if (pieceToRemoveCount <= 0)
         return false;
 
     // if piece is not their
@@ -951,24 +951,24 @@ bool Position::remove_piece(Square s, bool updateCmdlist)
         st.rule50 = 0;     // TODO: Need to move out?
     }
 
-    nPiecesOnBoard[them]--;
+    pieceOnBoardCount[them]--;
 
-    if (nPiecesOnBoard[them] + nPiecesInHand[them] < rule.nPiecesAtLeast) {
+    if (pieceOnBoardCount[them] + pieceInHandCount[them] < rule.piecesAtLeastCount) {
         set_gameover(sideToMove, GameOverReason::loseReasonlessThanThree);
         return true;
     }
 
     currentSquare = SQ_0;
 
-    nPiecesNeedRemove--;
+    pieceToRemoveCount--;
     update_key_misc();
 
-    if (nPiecesNeedRemove > 0) {
+    if (pieceToRemoveCount > 0) {
         return true;
     }
 
     if (phase == Phase::placing) {
-        if (nPiecesInHand[BLACK] == 0 && nPiecesInHand[WHITE] == 0) {
+        if (pieceInHandCount[BLACK] == 0 && pieceInHandCount[WHITE] == 0) {
             phase = Phase::moving;
             action = Action::select;
 
@@ -1123,7 +1123,7 @@ bool Position::check_if_game_is_over()
         return true;
     }
 
-    if (nPiecesOnBoard[BLACK] + nPiecesOnBoard[WHITE] >= EFFECTIVE_SQUARE_NB) {
+    if (pieceOnBoardCount[BLACK] + pieceOnBoardCount[WHITE] >= EFFECTIVE_SQUARE_NB) {
         if (rule.isBlackLoseButNotDrawWhenBoardFull) {
             set_gameover(WHITE, GameOverReason::loseReasonBoardIsFull);
         } else {
@@ -1227,7 +1227,7 @@ Key Position::update_key_misc()
 {
     st.key = st.key << Zobrist::KEY_MISC_BIT >> Zobrist::KEY_MISC_BIT;
 
-    st.key |= static_cast<Key>(nPiecesNeedRemove) << (CHAR_BIT * sizeof(Key) - Zobrist::KEY_MISC_BIT);
+    st.key |= static_cast<Key>(pieceToRemoveCount) << (CHAR_BIT * sizeof(Key) - Zobrist::KEY_MISC_BIT);
 
     return st.key;
 }
@@ -1486,7 +1486,7 @@ int Position::surrounded_empty_squares_count(Square s, bool includeFobidden)
 
     int n = 0;
 
-    if (nPiecesOnBoard[sideToMove] > rule.nPiecesAtLeast ||
+    if (pieceOnBoardCount[sideToMove] > rule.piecesAtLeastCount ||
         !rule.flyingAllowed) {
         Square moveSquare;
         for (MoveDirection d = MD_BEGIN; d < MD_NB; ++d) {
@@ -1537,11 +1537,11 @@ void Position::surrounded_pieces_count(Square s, int &nOurPieces, int &nTheirPie
 bool Position::is_all_surrounded() const
 {
     // Full
-    if (nPiecesOnBoard[BLACK] + nPiecesOnBoard[WHITE] >= EFFECTIVE_SQUARE_NB)
+    if (pieceOnBoardCount[BLACK] + pieceOnBoardCount[WHITE] >= EFFECTIVE_SQUARE_NB)
         return true;
 
     // Can fly
-    if (nPiecesOnBoard[sideToMove] <= rule.nPiecesAtLeast &&
+    if (pieceOnBoardCount[sideToMove] <= rule.piecesAtLeastCount &&
         rule.flyingAllowed) {
         return false;
     }
diff --git a/src/position.h b/src/position.h
index 1ac59bcb..14cf9e28 100644
--- a/src/position.h
+++ b/src/position.h
@@ -142,13 +142,13 @@ public:
 
     static void print_board();
 
-    int n_pieces_on_board_count();
-    int get_n_pieces_in_hand();
+    int piece_on_board_count_count();
+    int get_piece_in_hand_count();
 
-    int n_pieces_on_board(Color c);
-    int n_pieces_in_hand(Color c);
+    int piece_on_board_count(Color c);
+    int piece_in_hand_count(Color c);
 
-    int n_pieces_to_remove();
+    int piece_to_remove_count();
 
     static bool is_star_square(Square s);
 
@@ -178,9 +178,9 @@ public:
     Bitboard byTypeBB[PIECE_TYPE_NB];
     Bitboard byColorBB[COLOR_NB];
     // TODO: [0] is sum of Black and White
-    int nPiecesInHand[COLOR_NB]{ 0, 12, 12 }; // TODO
-    int nPiecesOnBoard[COLOR_NB]{ 0, 0, 0 };
-    int nPiecesNeedRemove{ 0 };
+    int pieceInHandCount[COLOR_NB]{ 0, 12, 12 }; // TODO
+    int pieceOnBoardCount[COLOR_NB]{ 0, 0, 0 };
+    int pieceToRemoveCount{ 0 };
     int gamePly { 0 };
     Color sideToMove { NOCOLOR };
     Thread *thisThread;
@@ -261,9 +261,9 @@ inline Piece Position::moved_piece(Move m) const
 template<PieceType Pt> inline int Position::count(Color c) const
 {
     if (Pt == ON_BOARD) {
-        return nPiecesOnBoard[c];
+        return pieceOnBoardCount[c];
     } else if (Pt == IN_HAND) {
-        return nPiecesInHand[c];
+        return pieceInHandCount[c];
     }
 
     return 0;
@@ -380,19 +380,19 @@ inline const char *Position::cmd_line() const
     return cmdline;
 }
 
-inline int Position::n_pieces_on_board(Color c)
+inline int Position::piece_on_board_count(Color c)
 {
-    return nPiecesOnBoard[c];
+    return pieceOnBoardCount[c];
 }
 
-inline int Position::n_pieces_in_hand(Color c)
+inline int Position::piece_in_hand_count(Color c)
 {
-    return nPiecesInHand[c];
+    return pieceInHandCount[c];
 }
 
-inline int Position::n_pieces_to_remove()
+inline int Position::piece_to_remove_count()
 {
-    return nPiecesNeedRemove;
+    return pieceToRemoveCount;
 }
 
 #endif // #ifndef POSITION_H_INCLUDED
diff --git a/src/rule.h b/src/rule.h
index 109e992c..98dbfa96 100644
--- a/src/rule.h
+++ b/src/rule.h
@@ -29,7 +29,7 @@ struct Rule
 
     int nTotalPiecesEachSide;   // 9 or 12
 
-    int nPiecesAtLeast; // Default is 3
+    int piecesAtLeastCount; // Default is 3
 
     bool hasObliqueLines;
 
diff --git a/src/search.cpp b/src/search.cpp
index 7acf66f0..69b84aa3 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -294,7 +294,7 @@ Value search(Position *pos, Sanmill::Stack<Position> &ss, Depth depth, Depth ori
 #endif /* TRANSPOSITION_TABLE_ENABLE */
 
 #if 0
-    if (position->phase == Phase::placing && depth == 1 && pos->nPiecesNeedRemove > 0) {
+    if (position->phase == Phase::placing && depth == 1 && pos->pieceToRemoveCount > 0) {
         depth--;
     }
 #endif
diff --git a/src/thread.cpp b/src/thread.cpp
index 214fee08..b1c0f5c5 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -469,13 +469,13 @@ Depth Thread::adjustDepth()
 
         // Can fly
         if (rule.flyingAllowed) {
-            if (pb == rule.nPiecesAtLeast ||
-                pw == rule.nPiecesAtLeast) {
+            if (pb == rule.piecesAtLeastCount ||
+                pw == rule.piecesAtLeastCount) {
                 d = flyingDepth;
             }
 
-            if (pb == rule.nPiecesAtLeast &&
-                pw == rule.nPiecesAtLeast) {
+            if (pb == rule.piecesAtLeastCount &&
+                pw == rule.piecesAtLeastCount) {
                 d = flyingDepth / 2;
             }
         }
diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index a6dfd9e2..c836ec6d 100644
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -72,9 +72,9 @@ void on_nTotalPiecesEachSide(const Option &o)
     rule.nTotalPiecesEachSide = (int)o;
 }
 
-void on_nPiecesAtLeast(const Option &o)
+void on_piecesAtLeastCount(const Option &o)
 {
-    rule.nPiecesAtLeast = (int)o;
+    rule.piecesAtLeastCount = (int)o;
 }
 
 void on_hasObliqueLines(const Option &o)
@@ -157,7 +157,7 @@ void init(OptionsMap &o)
 
     // Rules
     o["nTotalPiecesEachSide"] << Option(12, 6, 12, on_nTotalPiecesEachSide);
-    o["nPiecesAtLeast"] << Option(3, 3, 5, on_nPiecesAtLeast);
+    o["piecesAtLeastCount"] << Option(3, 3, 5, on_piecesAtLeastCount);
     o["hasObliqueLines"] << Option(true, on_hasObliqueLines);
     o["hasBannedLocations"] << Option(true, on_hasBannedLocations);
     o["isDefenderMoveFirst"] << Option(true, on_isDefenderMoveFirst);
diff --git a/src/ui/flutter/lib/common/config.dart b/src/ui/flutter/lib/common/config.dart
index 75990ea9..3ca75383 100644
--- a/src/ui/flutter/lib/common/config.dart
+++ b/src/ui/flutter/lib/common/config.dart
@@ -38,7 +38,7 @@ class Config {
 
   // Rules
   static int nTotalPiecesEachSide = 12;
-  static int nPiecesAtLeast = 3;
+  static int piecesAtLeastCount = 3;
   static bool hasObliqueLines = true;
   static bool hasBannedLocations = true;
   static bool isDefenderMoveFirst = true;
@@ -69,8 +69,8 @@ class Config {
     // Rules
     rule.nTotalPiecesEachSide =
         Config.nTotalPiecesEachSide = profile['nTotalPiecesEachSide'] ?? 12;
-    rule.nPiecesAtLeast =
-        Config.nPiecesAtLeast = profile['nPiecesAtLeast'] ?? 3;
+    rule.piecesAtLeastCount =
+        Config.piecesAtLeastCount = profile['piecesAtLeastCount'] ?? 3;
     rule.hasObliqueLines =
         Config.hasObliqueLines = profile['hasObliqueLines'] ?? true;
     rule.hasBannedLocations =
@@ -115,7 +115,7 @@ class Config {
 
     // Rules
     profile['nTotalPiecesEachSide'] = Config.nTotalPiecesEachSide;
-    profile['nPiecesAtLeast'] = Config.nPiecesAtLeast;
+    profile['piecesAtLeastCount'] = Config.piecesAtLeastCount;
     profile['hasObliqueLines'] = Config.hasObliqueLines;
     profile['hasBannedLocations'] = Config.hasBannedLocations;
     profile['isDefenderMoveFirst'] = Config.isDefenderMoveFirst;
diff --git a/src/ui/flutter/lib/engine/native_engine.dart b/src/ui/flutter/lib/engine/native_engine.dart
index 13690b64..0f2dc5e4 100644
--- a/src/ui/flutter/lib/engine/native_engine.dart
+++ b/src/ui/flutter/lib/engine/native_engine.dart
@@ -136,7 +136,8 @@ class NativeEngine extends AiEngine {
     await send('setoption name Shuffling value ${Config.shufflingEnabled}');
     await send(
         'setoption name nTotalPiecesEachSide value ${Config.nTotalPiecesEachSide}');
-    await send('setoption name nPiecesAtLeast value ${Config.nPiecesAtLeast}');
+    await send(
+        'setoption name piecesAtLeastCount value ${Config.piecesAtLeastCount}');
     await send(
         'setoption name hasObliqueLines value ${Config.hasObliqueLines}');
     await send(
diff --git a/src/ui/flutter/lib/l10n/intl_en.arb b/src/ui/flutter/lib/l10n/intl_en.arb
index a2e2c38e..f472cecf 100644
--- a/src/ui/flutter/lib/l10n/intl_en.arb
+++ b/src/ui/flutter/lib/l10n/intl_en.arb
@@ -323,8 +323,8 @@
   "@twelvePieces": {
     "description": "Twelve Pieces"
   },
-  "nPiecesAtLeast": "Pieces At Least",
-  "@nPiecesAtLeast": {
+  "piecesAtLeastCount": "Pieces At Least",
+  "@piecesAtLeastCount": {
     "description": "Pieces At Least"
   },
   "hasObliqueLines": "Has Oblique Lines",
diff --git a/src/ui/flutter/lib/l10n/intl_zh.arb b/src/ui/flutter/lib/l10n/intl_zh.arb
index 9aca1f38..5f7fce30 100644
--- a/src/ui/flutter/lib/l10n/intl_zh.arb
+++ b/src/ui/flutter/lib/l10n/intl_zh.arb
@@ -80,7 +80,7 @@
   "nTotalPiecesEachSide": "棋子数",
   "ninePieces": "九子",
   "twelvePieces": "十二子",
-  "nPiecesAtLeast": "少于几个子则输棋",
+  "piecesAtLeastCount": "少于几个子则输棋",
   "hasObliqueLines": "斜线",
   "hasBannedLocations": "禁点",
   "isDefenderMoveFirst": "后摆子的先走子",
diff --git a/src/ui/flutter/lib/mill/position.dart b/src/ui/flutter/lib/mill/position.dart
index 8046a5c6..041ebdf4 100644
--- a/src/ui/flutter/lib/mill/position.dart
+++ b/src/ui/flutter/lib/mill/position.dart
@@ -46,9 +46,9 @@ class Position {
 
   GameRecorder recorder;
 
-  Map<String, int> nPiecesInHand = {Color.black: -1, Color.white: -1};
-  Map<String, int> nPiecesOnBoard = {Color.black: 0, Color.white: 0};
-  int nPiecesNeedRemove = 0;
+  Map<String, int> pieceInHandCount = {Color.black: -1, Color.white: -1};
+  Map<String, int> pieceOnBoardCount = {Color.black: 0, Color.white: 0};
+  int pieceToRemoveCount = 0;
 
   int gamePly = 0;
   String _sideToMove = Color.black;
@@ -102,9 +102,9 @@ class Position {
 
     recorder = other.recorder;
 
-    nPiecesInHand = other.nPiecesInHand;
-    nPiecesOnBoard = other.nPiecesOnBoard;
-    nPiecesNeedRemove = other.nPiecesNeedRemove;
+    pieceInHandCount = other.pieceInHandCount;
+    pieceOnBoardCount = other.pieceOnBoardCount;
+    pieceToRemoveCount = other.pieceToRemoveCount;
 
     gamePly = other.gamePly;
 
@@ -242,15 +242,15 @@ class Position {
 
     ss += " ";
 
-    ss += nPiecesOnBoard[Color.black].toString() +
+    ss += pieceOnBoardCount[Color.black].toString() +
         " " +
-        nPiecesInHand[Color.black].toString() +
+        pieceInHandCount[Color.black].toString() +
         " " +
-        nPiecesOnBoard[Color.white].toString() +
+        pieceOnBoardCount[Color.white].toString() +
         " " +
-        nPiecesInHand[Color.white].toString() +
+        pieceInHandCount[Color.white].toString() +
         " " +
-        nPiecesNeedRemove.toString() +
+        pieceToRemoveCount.toString() +
         " ";
 
     int sideIsBlack = _sideToMove == Color.black ? 1 : 0;
@@ -370,35 +370,35 @@ class Position {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-  int nPiecesOnBoardCount() {
-    nPiecesOnBoard[Color.black] = nPiecesOnBoard[Color.white] = 0;
+  int pieceOnBoardCountCount() {
+    pieceOnBoardCount[Color.black] = pieceOnBoardCount[Color.white] = 0;
 
     for (int f = 1; f < fileExNumber; f++) {
       for (int r = 0; r < rankNumber; r++) {
         int s = f * rankNumber + r;
         if (board[s] == Piece.blackStone) {
-          nPiecesOnBoard[Color.black]++;
+          pieceOnBoardCount[Color.black]++;
         } else if (board[s] == Piece.whiteStone) {
-          nPiecesOnBoard[Color.black]++;
+          pieceOnBoardCount[Color.black]++;
         }
       }
     }
 
-    if (nPiecesOnBoard[Color.black] > rule.nTotalPiecesEachSide ||
-        nPiecesOnBoard[Color.white] > rule.nTotalPiecesEachSide) {
+    if (pieceOnBoardCount[Color.black] > rule.nTotalPiecesEachSide ||
+        pieceOnBoardCount[Color.white] > rule.nTotalPiecesEachSide) {
       return -1;
     }
 
-    return nPiecesOnBoard[Color.black] + nPiecesOnBoard[Color.white];
+    return pieceOnBoardCount[Color.black] + pieceOnBoardCount[Color.white];
   }
 
   int GetNPiecesInHand() {
-    nPiecesInHand[Color.black] =
-        rule.nTotalPiecesEachSide - nPiecesOnBoard[Color.black];
-    nPiecesInHand[Color.white] =
-        rule.nTotalPiecesEachSide - nPiecesOnBoard[Color.white];
+    pieceInHandCount[Color.black] =
+        rule.nTotalPiecesEachSide - pieceOnBoardCount[Color.black];
+    pieceInHandCount[Color.white] =
+        rule.nTotalPiecesEachSide - pieceOnBoardCount[Color.white];
 
-    return nPiecesOnBoard[Color.black] + nPiecesOnBoard[Color.white];
+    return pieceOnBoardCount[Color.black] + pieceOnBoardCount[Color.white];
   }
 
   void clearBoard() {
@@ -428,12 +428,12 @@ class Position {
 
     clearBoard();
 
-    if (nPiecesOnBoardCount() == -1) {
+    if (pieceOnBoardCountCount() == -1) {
       return -1;
     }
 
     GetNPiecesInHand();
-    nPiecesNeedRemove = 0;
+    pieceToRemoveCount = 0;
 
     winner = Color.nobody;
     createMoveTable();
@@ -456,10 +456,10 @@ class Position {
 
     clearBoard();
 
-    nPiecesOnBoard[Color.black] = nPiecesOnBoard[Color.white] = 0;
-    nPiecesInHand[Color.black] =
-        nPiecesInHand[Color.white] = rule.nTotalPiecesEachSide;
-    nPiecesNeedRemove = 0;
+    pieceOnBoardCount[Color.black] = pieceOnBoardCount[Color.white] = 0;
+    pieceInHandCount[Color.black] =
+        pieceInHandCount[Color.white] = rule.nTotalPiecesEachSide;
+    pieceToRemoveCount = 0;
 
     currentSquare = 0;
     int i = 0; // TODO: rule
@@ -513,8 +513,8 @@ class Position {
 
     if (phase == Phase.placing) {
       piece = sideToMove();
-      nPiecesInHand[us]--;
-      nPiecesOnBoard[us]++;
+      pieceInHandCount[us]--;
+      pieceOnBoardCount[us]++;
 
       _grid[index] = piece;
       board[s] = piece;
@@ -526,11 +526,11 @@ class Position {
       int n = addMills(currentSquare);
 
       if (n == 0) {
-        assert(
-            nPiecesInHand[Color.black] >= 0 && nPiecesInHand[Color.white] >= 0);
+        assert(pieceInHandCount[Color.black] >= 0 &&
+            pieceInHandCount[Color.white] >= 0);
 
-        if (nPiecesInHand[Color.black] == 0 &&
-            nPiecesInHand[Color.white] == 0) {
+        if (pieceInHandCount[Color.black] == 0 &&
+            pieceInHandCount[Color.white] == 0) {
           if (checkIfGameIsOver()) {
             return true;
           }
@@ -553,7 +553,7 @@ class Position {
           changeSideToMove();
         }
       } else {
-        nPiecesNeedRemove =
+        pieceToRemoveCount =
             rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
         action = Act.remove;
       }
@@ -563,7 +563,7 @@ class Position {
       }
 
       // if illegal
-      if (nPiecesOnBoard[sideToMove()] > rule.nPiecesAtLeast ||
+      if (pieceOnBoardCount[sideToMove()] > rule.piecesAtLeastCount ||
           !rule.flyingAllowed) {
         int md;
 
@@ -606,7 +606,7 @@ class Position {
           return true;
         }
       } else {
-        nPiecesNeedRemove =
+        pieceToRemoveCount =
             rule.allowRemoveMultiPiecesWhenCloseMultiMill ? n : 1;
         action = Act.remove;
       }
@@ -622,7 +622,7 @@ class Position {
 
     if (action != Act.remove) return false;
 
-    if (nPiecesNeedRemove <= 0) return false;
+    if (pieceToRemoveCount <= 0) return false;
 
     // if piece is not their
     if (!(Color.opponent(sideToMove()) == board[s])) return false;
@@ -643,23 +643,25 @@ class Position {
     cmdline = "-(" + fileOf(s).toString() + "," + rankOf(s).toString() + ")";
     rule50 = 0; // TODO: Need to move out?
 
-    nPiecesOnBoard[them]--;
+    pieceOnBoardCount[them]--;
 
-    if (nPiecesOnBoard[them] + nPiecesInHand[them] < rule.nPiecesAtLeast) {
+    if (pieceOnBoardCount[them] + pieceInHandCount[them] <
+        rule.piecesAtLeastCount) {
       setGameOver(sideToMove(), GameOverReason.loseReasonlessThanThree);
       return true;
     }
 
     currentSquare = 0;
 
-    nPiecesNeedRemove--;
+    pieceToRemoveCount--;
 
-    if (nPiecesNeedRemove > 0) {
+    if (pieceToRemoveCount > 0) {
       return true;
     }
 
     if (phase == Phase.placing) {
-      if (nPiecesInHand[Color.black] == 0 && nPiecesInHand[Color.white] == 0) {
+      if (pieceInHandCount[Color.black] == 0 &&
+          pieceInHandCount[Color.white] == 0) {
         phase = Phase.moving;
         action = Act.select;
 
@@ -749,7 +751,7 @@ class Position {
       return true;
     }
 
-    if (nPiecesOnBoard[Color.black] + nPiecesOnBoard[Color.white] >=
+    if (pieceOnBoardCount[Color.black] + pieceOnBoardCount[Color.white] >=
         rankNumber * fileNumber) {
       if (rule.isBlackLoseButNotDrawWhenBoardFull) {
         setGameOver(Color.white, GameOverReason.loseReasonBoardIsFull);
@@ -1408,14 +1410,14 @@ class Position {
 
   bool isAllSurrounded() {
     // Full
-    if (nPiecesOnBoard[Color.black] + nPiecesOnBoard[Color.white] >=
+    if (pieceOnBoardCount[Color.black] + pieceOnBoardCount[Color.white] >=
         rankNumber * fileNumber) {
       //print("Board is full.");
       return true;
     }
 
     // Can fly
-    if (nPiecesOnBoard[sideToMove()] <= rule.nPiecesAtLeast &&
+    if (pieceOnBoardCount[sideToMove()] <= rule.piecesAtLeastCount &&
         rule.flyingAllowed) {
       //print("Can fly.");
       return false;
diff --git a/src/ui/flutter/lib/mill/rule.dart b/src/ui/flutter/lib/mill/rule.dart
index 594541af..f82132d1 100644
--- a/src/ui/flutter/lib/mill/rule.dart
+++ b/src/ui/flutter/lib/mill/rule.dart
@@ -20,7 +20,7 @@ class Rule {
   String name = "Da San Qi";
   String description;
   int nTotalPiecesEachSide = 12; // 9 or 12
-  int nPiecesAtLeast = 3; // Default is 3
+  int piecesAtLeastCount = 3; // Default is 3
   bool hasObliqueLines = true;
   bool hasBannedLocations = true;
   bool isDefenderMoveFirst = true;
diff --git a/src/ui/flutter/lib/widgets/settings_page.dart b/src/ui/flutter/lib/widgets/settings_page.dart
index 598b828b..64aefb49 100644
--- a/src/ui/flutter/lib/widgets/settings_page.dart
+++ b/src/ui/flutter/lib/widgets/settings_page.dart
@@ -251,7 +251,7 @@ class _SettingsPageState extends State<SettingsPage> {
   setNPiecesAtLeast(int value) async {
     //
     setState(() {
-      rule.nPiecesAtLeast = Config.nPiecesAtLeast = value;
+      rule.piecesAtLeastCount = Config.piecesAtLeastCount = value;
     });
 
     Config.save();
diff --git a/src/ui/qt/game.cpp b/src/ui/qt/game.cpp
index 4315c00b..f6cb769a 100644
--- a/src/ui/qt/game.cpp
+++ b/src/ui/qt/game.cpp
@@ -1537,15 +1537,15 @@ void Game::setTips()
 
     switch (p.phase) {
     case Phase::ready:
-        tips = "轮到" + turnStr + "落子，剩余" + std::to_string(p.nPiecesInHand[BLACK]) + "子" +
+        tips = "轮到" + turnStr + "落子，剩余" + std::to_string(p.pieceInHandCount[BLACK]) + "子" +
             "  比分 " + to_string(p.score[BLACK]) + ":" + to_string(p.score[WHITE]) + ", 和棋 " + to_string(p.score_draw);
         break;
 
     case Phase::placing:
         if (p.action == Action::place) {
-            tips = "轮到" + turnStr + "落子，剩余" + std::to_string(p.nPiecesInHand[p.sideToMove]) + "子";
+            tips = "轮到" + turnStr + "落子，剩余" + std::to_string(p.pieceInHandCount[p.sideToMove]) + "子";
         } else if (p.action == Action::remove) {
-            tips = "成三！轮到" + turnStr + "去子，需去" + std::to_string(p.nPiecesNeedRemove) + "子";
+            tips = "成三！轮到" + turnStr + "去子，需去" + std::to_string(p.pieceToRemoveCount) + "子";
         }
         break;
 
@@ -1553,7 +1553,7 @@ void Game::setTips()
         if (p.action == Action::place || p.action == Action::select) {
             tips = "轮到" + turnStr + "选子移动";
         } else if (p.action == Action::remove) {
-            tips = "成三！轮到" + turnStr + "去子，需去" + std::to_string(p.nPiecesNeedRemove) + "子";
+            tips = "成三！轮到" + turnStr + "去子，需去" + std::to_string(p.pieceToRemoveCount) + "子";
         }
         break;