diff --git a/src/aithread.cpp b/src/aithread.cpp
index f76f95d2..8052e8b4 100644
--- a/src/aithread.cpp
+++ b/src/aithread.cpp
@@ -118,7 +118,8 @@ void sq2str(char *str)
         sig = 0;
     }
 
-    Position::square_to_polar((Square)sq, file, rank);
+    file = file_of(sq);
+    rank = rank_of(sq);
 
     if (sig == 1) {
         sprintf_s(str, 16, "(%d,%d)", file, rank);
diff --git a/src/position.cpp b/src/position.cpp
index 198d8fb6..ea4d6625 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -616,7 +616,8 @@ bool Position::put_piece(Square s, bool updateCmdlist)
         start();
     }        
 
-    Position::square_to_polar(s, file, rank);
+    file = file_of(s);
+    rank = rank_of(s);
 
     if (phase == PHASE_PLACING) {
         piece = (Piece)((0x01 | (sideToMove << PLAYER_SHIFT)) + rule.nTotalPiecesEachSide - pieceCountInHand[us]);
@@ -753,9 +754,8 @@ bool Position::remove_piece(Square s, bool updateCmdlist)
     if (pieceCountNeedRemove <= 0)
         return false;
 
-    File file;
-    Rank rank;
-    Position::square_to_polar(s, file, rank);
+    File file = file_of(s);
+    Rank rank = rank_of(s);
 
     int seconds = -1;
 
@@ -1447,14 +1447,6 @@ void Position::create_mill_table()
 #endif /* DEBUG_MODE */
 }
 
-void Position::square_to_polar(const Square s, File &file, Rank &rank)
-{
-    //r = s / RANK_NB;
-    //s = s % RANK_NB + 1;
-    file = File(s >> 3);
-    rank = Rank((s & 0x07) + 1);
-}
-
 Color Position::color_on(Square s) const
 {
     return Color((board[s] & 0x30) >> PLAYER_SHIFT);
diff --git a/src/position.h b/src/position.h
index bb79fab2..308eb46c 100644
--- a/src/position.h
+++ b/src/position.h
@@ -157,8 +157,6 @@ public:
     void surrounded_pieces_count(Square s, int &nOurPieces, int &nTheirPieces, int &nBanned, int &nEmpty);
     bool is_all_surrounded() const;
 
-    static void square_to_polar(Square s, File &file, Rank &rank);
-
     static void print_board();
 
     int pieces_on_board_count();
diff --git a/src/search.cpp b/src/search.cpp
index 1acc6c0f..17fd7123 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -604,16 +604,14 @@ const char* AIAlgorithm::nextMove()
 
 const char *AIAlgorithm::moveToCommand(Move move)
 {
-    File file2;
-    Rank rank2;
-    Position::square_to_polar(to_sq(move), file2, rank2);
+    File file2 = file_of(to_sq(move));
+    Rank rank2 = rank_of(to_sq(move));
 
     if (move < 0) {
         sprintf(cmdline, "-(%1u,%1u)", file2, rank2);
     } else if (move & 0x7f00) {
-        File file1;
-        Rank rank1;
-        Position::square_to_polar(from_sq(move), file1, rank1);
+        File file1 = file_of(from_sq(move));
+        Rank rank1 = rank_of(from_sq(move));
         sprintf(cmdline, "(%1u,%1u)->(%1u,%1u)", file1, rank1, file2, rank2);
     } else {
         sprintf(cmdline, "(%1u,%1u)", file2, rank2);
diff --git a/src/types.h b/src/types.h
index f8a7de67..561b5ea8 100644
--- a/src/types.h
+++ b/src/types.h
@@ -481,26 +481,14 @@ constexpr bool is_ok(Square s)
 
 constexpr File file_of(Square s)
 {
-    return File((s >> 3) - 1);
+    return File(s >> 3);
 }
 
 constexpr Rank rank_of(Square s)
 {
-    return Rank(s & 7);
+    return Rank((s & 0x07) + 1);
 }
 
-#if 0
-constexpr ring_t ring_of(Square s)
-{
-   // return File(s & 7);
-}
-
-constexpr Rank seat_of(Square s)
-{
-    //return seat(s >> 3);
-}
-#endif
-
 constexpr Square from_sq(Move m)
 {
     return static_cast<Square>(m >> 8);