diff --git a/src/Lynx/MoveGenerator.cs b/src/Lynx/MoveGenerator.cs
index 245bcf99d..b0986c3e2 100644
--- a/src/Lynx/MoveGenerator.cs
+++ b/src/Lynx/MoveGenerator.cs
@@ -65,12 +65,7 @@ internal static Move[] GenerateAllMoves(Position position, bool capturesOnly = f
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Span<Move> GenerateAllMoves(Position position, Span<Move> movePool)
     {
-#if DEBUG
-        if (position.Side == Side.Both)
-        {
-            return [];
-        }
-#endif
+        Debug.Assert(position.Side != Side.Both);
 
         int localIndex = 0;
 
@@ -96,12 +91,7 @@ public static Span<Move> GenerateAllMoves(Position position, Span<Move> movePool
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Move[] GenerateAllCaptures(Position position, Move[] movePool)
     {
-#if DEBUG
-        if (position.Side == Side.Both)
-        {
-            return [];
-        }
-#endif
+        Debug.Assert(position.Side != Side.Both);
 
         int localIndex = 0;
 
@@ -127,12 +117,8 @@ public static Move[] GenerateAllCaptures(Position position, Move[] movePool)
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Span<Move> GenerateAllCaptures(Position position, Span<Move> movePool)
     {
-#if DEBUG
-        if (position.Side == Side.Both)
-        {
-            return [];
-        }
-#endif
+        Debug.Assert(position.Side != Side.Both);
+
 
         int localIndex = 0;
 
@@ -166,13 +152,7 @@ internal static void GenerateAllPawnMoves(ref int localIndex, Span<Move> movePoo
 
             var sourceRank = (sourceSquare >> 3) + 1;
 
-#if DEBUG
-            if (sourceRank == 1 || sourceRank == 8)
-            {
-                _logger.Warn("There's a non-promoted {0} pawn in rank {1}", position.Side, sourceRank);
-                continue;
-            }
-#endif
+            Debug.Assert(sourceRank != 1 && sourceRank != 8, $"There's a non-promoted {position.Side} pawn in rank {sourceRank})");
 
             // Pawn pushes
             var singlePushSquare = sourceSquare + pawnPush;
@@ -252,13 +232,7 @@ internal static void GeneratePawnCapturesAndPromotions(ref int localIndex, Span<
 
             var sourceRank = (sourceSquare >> 3) + 1;
 
-#if DEBUG
-            if (sourceRank == 1 || sourceRank == 8)
-            {
-                _logger.Warn("There's a non-promoted {0} pawn in rank {1}", position.Side, sourceRank);
-                continue;
-            }
-#endif
+            Debug.Assert(sourceRank != 1 && sourceRank != 8, $"There's a non-promoted {position.Side} pawn in rank {sourceRank})");
 
             // Pawn pushes
             var singlePushSquare = sourceSquare + pawnPush;
@@ -464,12 +438,7 @@ internal static void GeneratePieceCaptures(ref int localIndex, Span<Move> movePo
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool CanGenerateAtLeastAValidMove(Position position)
     {
-#if DEBUG
-        if (position.Side == Side.Both)
-        {
-            return false;
-        }
-#endif
+        Debug.Assert(position.Side != Side.Both);
 
         var offset = Utils.PieceOffset(position.Side);
 
@@ -488,7 +457,7 @@ public static bool CanGenerateAtLeastAValidMove(Position position)
         }
         catch (Exception e)
         {
-            Debug.Fail($"Error in {nameof(CanGenerateAtLeastAValidMove)}", e.StackTrace);
+            _logger.Error(e, $"Error in {nameof(CanGenerateAtLeastAValidMove)}");
             return false;
         }
 #endif
@@ -511,13 +480,8 @@ private static bool IsAnyPawnMoveValid(Position position, int offset)
 
             var sourceRank = (sourceSquare >> 3) + 1;
 
-#if DEBUG
-            if (sourceRank == 1 || sourceRank == 8)
-            {
-                _logger.Warn("There's a non-promoted {0} pawn in rank {1}", position.Side, sourceRank);
-                continue;
-            }
-#endif
+            Debug.Assert(sourceRank != 1 && sourceRank != 8, $"There's a non-promoted {position.Side} pawn in rank {sourceRank})");
+
             // Pawn pushes
             var singlePushSquare = sourceSquare + pawnPush;
             if (!position.OccupancyBitBoards[2].GetBit(singlePushSquare))
diff --git a/src/Lynx/UCIHandler.cs b/src/Lynx/UCIHandler.cs
index dbd94a23c..e604481dd 100644
--- a/src/Lynx/UCIHandler.cs
+++ b/src/Lynx/UCIHandler.cs
@@ -131,17 +131,17 @@ static ReadOnlySpan<char> ExtractCommandItems(string rawCommand)
 
     private void HandlePosition(ReadOnlySpan<char> command)
     {
-        var sw = Stopwatch.StartNew();
 #if DEBUG
+        var sw = Stopwatch.StartNew();
         _engine.Game.CurrentPosition.Print();
 #endif
 
         _engine.AdjustPosition(command);
+
 #if DEBUG
         _engine.Game.CurrentPosition.Print();
-#endif
-
         _logger.Info("Position parsing took {0}ms", sw.ElapsedMilliseconds);
+#endif
     }
 
     private void HandleStop() => _engine.StopSearching();
diff --git a/src/Lynx/ZobristTable.cs b/src/Lynx/ZobristTable.cs
index 09d56cfe3..f173d0e7b 100644
--- a/src/Lynx/ZobristTable.cs
+++ b/src/Lynx/ZobristTable.cs
@@ -1,4 +1,5 @@
 using Lynx.Model;
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
 namespace Lynx;
@@ -35,12 +36,8 @@ public static ulong EnPassantHash(int enPassantSquare)
             return default;
         }
 
-#if DEBUG
-        if (Constants.EnPassantCaptureSquares.Length <= enPassantSquare || Constants.EnPassantCaptureSquares[enPassantSquare] == 0)
-        {
-            throw new ArgumentException($"{Constants.Coordinates[enPassantSquare]} is not a valid en-passant square");
-        }
-#endif
+        Debug.Assert(Constants.EnPassantCaptureSquares.Length > enPassantSquare && Constants.EnPassantCaptureSquares[enPassantSquare] != 0,
+            $"{Constants.Coordinates[enPassantSquare]} is not a valid en-passant square");
 
         var file = enPassantSquare & 0x07;  // enPassantSquare % 8
 
diff --git a/tests/Lynx.Test/MoveGeneration/GeneratePawnMovesTest.cs b/tests/Lynx.Test/MoveGeneration/GeneratePawnMovesTest.cs
index 8ac288c7b..44a2a6b87 100644
--- a/tests/Lynx.Test/MoveGeneration/GeneratePawnMovesTest.cs
+++ b/tests/Lynx.Test/MoveGeneration/GeneratePawnMovesTest.cs
@@ -233,10 +233,6 @@ public void DoubleEnPassant(string fen)
         Assert.AreEqual(2, moves.Count(m => m.IsEnPassant() && m.IsCapture()));
     }
 
-#if DEBUG
-    [TestCase("PPPPPPPP/8/8/8/8/8/8/8 w - - 0 1", Description = "Last rank")]
-    [TestCase("8/8/8/8/8/8/8/pppppppp b - - 0 1", Description = "Last rank")]
-#endif
     [TestCase("8/8/8/p1p1p1p1/PpPpPpPp/1P1P1P1P/8/8 w - - 0 1", Description = "Blocked position")]
     [TestCase("8/8/8/p1p1p1p1/PpPpPpPp/1P1P1P1P/8/8 b - - 0 1", Description = "Blocked position")]
     [TestCase("8/8/8/N7/P7/1p6/8/8 w - - 0 1", Description = "Backwards/inverse capture")]
diff --git a/tests/Lynx.Test/ZobristTableTest.cs b/tests/Lynx.Test/ZobristTableTest.cs
index 339a69c02..98378f3ab 100644
--- a/tests/Lynx.Test/ZobristTableTest.cs
+++ b/tests/Lynx.Test/ZobristTableTest.cs
@@ -66,17 +66,6 @@ public void EnPassantHash()
         }
 
         Assert.AreEqual(16, enPassantSquares.Count());
-
-#if DEBUG
-        for (int square = 0; square < 64; ++square)
-        {
-            var rank = square / 8;
-            if (rank != 2 && rank != 5)
-            {
-                Assert.Throws<ArgumentException>(() => ZobristTable.EnPassantHash(square));
-            }
-        }
-#endif
     }
 
     [Test]