diff --git a/src/types.h b/src/types.h
index 2d311418..a0635b8f 100644
--- a/src/types.h
+++ b/src/types.h
@@ -65,27 +65,6 @@ template<Color C, CastlingSide S> struct MakeCastling {
                      : S == QUEEN_SIDE ? BLACK_OOO : BLACK_OO;
 };
 
-enum Phase {
-  PHASE_ENDGAME,
-  PHASE_MIDGAME = 128,
-  MG = 0, EG = 1, PHASE_NB = 2
-};
-
-enum ScaleFactor {
-  SCALE_FACTOR_DRAW    = 0,
-  SCALE_FACTOR_ONEPAWN = 48,
-  SCALE_FACTOR_NORMAL  = 64,
-  SCALE_FACTOR_MAX     = 128,
-  SCALE_FACTOR_NONE    = 255
-};
-
-enum Bound {
-  BOUND_NONE,
-  BOUND_UPPER,
-  BOUND_LOWER,
-  BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
-};
-
 enum PieceType {
   NO_PIECE_TYPE, PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING,
   ALL_PIECES = 0,
@@ -99,18 +78,6 @@ enum Piece {
   PIECE_NB = 16
 };
 
-enum Depth {
-
-  ONE_PLY = 1,
-
-  DEPTH_ZERO          =  0,
-  DEPTH_QS_CHECKS     =  0,
-  DEPTH_QS_NO_CHECKS  = -1,
-  DEPTH_QS_RECAPTURES = -5,
-
-  DEPTH_NONE = -6
-};
-
 enum Square {
   SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
   SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
@@ -145,20 +112,6 @@ enum Rank {
   RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
 };
 
-
-/// The Score enum stores a middlegame and an endgame value in a single integer
-/// (enum). The least significant 16 bits are used to store the endgame value
-/// and the upper 16 bits are used to store the middlegame value. The compiler
-/// is free to choose the enum type as long as it can store the data, so we
-/// ensure that Score is an integer type by assigning some big int values.
-enum Score {
-  SCORE_ZERO,
-  SCORE_ENSURE_INTEGER_SIZE_P = INT_MAX,
-  SCORE_ENSURE_INTEGER_SIZE_N = INT_MIN
-};
-
-inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
-
 #define ENABLE_BASE_OPERATORS_ON(T)                             \
 inline T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
 inline T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
@@ -169,8 +122,6 @@ inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; }      \
 inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }      \
 inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }
 
-ENABLE_BASE_OPERATORS_ON(Score)
-
 #define ENABLE_FULL_OPERATORS_ON(T)                             \
 ENABLE_BASE_OPERATORS_ON(T)                                     \
 inline T& operator++(T& d) { return d = T(int(d) + 1); }        \
@@ -182,7 +133,6 @@ inline T& operator/=(T& d, int i) { return d = T(int(d) / i); }
 ENABLE_FULL_OPERATORS_ON(PieceType)
 ENABLE_FULL_OPERATORS_ON(Piece)
 ENABLE_FULL_OPERATORS_ON(Color)
-ENABLE_FULL_OPERATORS_ON(Depth)
 ENABLE_FULL_OPERATORS_ON(Square)
 ENABLE_FULL_OPERATORS_ON(File)
 ENABLE_FULL_OPERATORS_ON(Rank)
@@ -190,10 +140,6 @@ ENABLE_FULL_OPERATORS_ON(Rank)
 #undef ENABLE_FULL_OPERATORS_ON
 #undef ENABLE_BASE_OPERATORS_ON
 
-/// Only declared but not defined. We don't want to multiply two scores due to
-/// a very high risk of overflow. So user should explicitly convert to integer.
-inline Score operator*(Score s1, Score s2);
-
 struct ExtMove {
   Move move;
   int value;