diff --git a/Chess-Challenge/src/Framework/Application/Helpers/Tester.cs b/Chess-Challenge/src/Framework/Application/Helpers/Tester.cs
index eef4fee..600a81e 100644
--- a/Chess-Challenge/src/Framework/Application/Helpers/Tester.cs
+++ b/Chess-Challenge/src/Framework/Application/Helpers/Tester.cs
@@ -113,6 +113,17 @@ namespace ChessChallenge.Application
             Assert(boardAPI.GetKingSquare(false) == new Square(6, 7), "King square wrong");
             Assert(boardAPI.GetPiece(new Square(4, 5)).IsPawn, "Wrong piece");
             Assert(!boardAPI.GetPiece(new Square(4, 5)).IsWhite, "Wrong colour");
+
+            API.Move testMove = new("g5e6", boardAPI);
+            boardAPI.MakeMove(testMove);
+            Assert(boardAPI.GetPiece(new Square("g5")).IsNull, "Wrong piece");
+            Assert(boardAPI.GetPiece(new Square("e6")).IsKnight, "Wrong piece");
+            Assert(boardAPI.GetPiece(new Square("e6")).IsWhite, "Wrong piece col");
+            boardAPI.UndoMove(testMove);
+            Assert(boardAPI.GetPiece(new Square("e6")).IsPawn, "Wrong piece");
+            Assert(!boardAPI.GetPiece(new Square("e6")).IsWhite, "Wrong piece col");
+            Assert(boardAPI.GetPiece(new Square("g5")).IsKnight, "Wrong piece");
+
         }
 
         static void DrawTest()
@@ -151,6 +162,43 @@ namespace ChessChallenge.Application
             Assert(!boardAPI.IsDraw(), "Draw wrong");
             boardAPI.MakeMove(new API.Move("c5d7", boardAPI));
             Assert(boardAPI.IsDraw(), "Draw wrong");
+
+            string[] notInsufficient =
+            {
+                "3k4/4b3/8/8/8/3B4/1K6/8 w - - 0 1",
+                "3k4/3b4/8/8/8/4B3/1K6/8 w - - 0 1",
+                "3k4/3b4/8/8/8/2N5/1K6/8 w - - 0 1",
+                "3k4/3n4/8/8/8/2N5/1K6/8 w - - 0 1",
+                "8/4k3/8/8/8/2NN4/1K6/8 w - - 0 1",
+                "8/4k3/8/8/8/8/PK6/8 w - - 0 1",
+                "8/4k3/8/8/8/8/1K1R4/8 w - - 0 1",
+                "8/4k3/8/8/8/8/1KQ5/8 w - - 0 1"
+            };
+
+            string[] insufficient =
+            {
+                "3k4/8/8/8/8/8/1K6/8 w - - 0 1",
+                "3k4/8/8/8/8/2B5/1K6/8 w - - 0 1",
+                "3k4/8/8/8/8/8/1KN5/8 w - - 0 1",
+                "3k4/2b5/8/8/8/2B5/1K6/8 w - - 0 1",
+                "3k4/3b4/8/8/8/3B4/1K6/8 w - - 0 1"
+            };
+
+            foreach (string drawPos in insufficient)
+            {
+                boardAPI = API.Board.CreateBoardFromFEN(drawPos);
+                Assert(boardAPI.IsDraw(), "Draw wrong, position is insufficient mat");
+                boardAPI = API.Board.CreateBoardFromFEN(FenUtility.FlipFen(drawPos));
+                Assert(boardAPI.IsDraw(), "Draw wrong, position is insufficient mat");
+            }
+
+            foreach (string winnablePos in notInsufficient)
+            {
+                boardAPI = API.Board.CreateBoardFromFEN(winnablePos);
+                Assert(!boardAPI.IsDraw(), "Draw wrong, position is winnable");
+                boardAPI = API.Board.CreateBoardFromFEN(FenUtility.FlipFen(winnablePos));
+                Assert(!boardAPI.IsDraw(), "Draw wrong, position is winnable");
+            }
         }
 
         static void MiscTest()
diff --git a/Chess-Challenge/src/Framework/Chess/Board/Board.cs b/Chess-Challenge/src/Framework/Chess/Board/Board.cs
index fa683f7..3d1daef 100644
--- a/Chess-Challenge/src/Framework/Chess/Board/Board.cs
+++ b/Chess-Challenge/src/Framework/Chess/Board/Board.cs
@@ -266,9 +266,12 @@ namespace ChessChallenge.Chess
             UpdateSliderBitboards();
 
             // Pawn moves and captures reset the fifty move counter and clear 3-fold repetition history
-            if (!inSearch && (movedPieceType == PieceHelper.Pawn || capturedPieceType != PieceHelper.None))
+            if (movedPieceType == PieceHelper.Pawn || capturedPieceType != PieceHelper.None)
             {
-                RepetitionPositionHistory.Clear();
+                if (!inSearch)
+                {
+                    RepetitionPositionHistory.Clear();
+                }
                 newFiftyMoveCounter = 0;
             }
 
diff --git a/Chess-Challenge/src/Framework/Chess/Helpers/BoardHelper.cs b/Chess-Challenge/src/Framework/Chess/Helpers/BoardHelper.cs
index 4457ca8..fa3444f 100644
--- a/Chess-Challenge/src/Framework/Chess/Helpers/BoardHelper.cs
+++ b/Chess-Challenge/src/Framework/Chess/Helpers/BoardHelper.cs
@@ -60,6 +60,11 @@
             return (fileIndex + rankIndex) % 2 != 0;
         }
 
+        public static bool LightSquare(int squareIndex)
+        {
+            return LightSquare(FileIndex(squareIndex), RankIndex(squareIndex));
+        }
+
         public static string SquareNameFromCoordinate(int fileIndex, int rankIndex)
         {
             return fileNames[fileIndex] + "" + (rankIndex + 1);
diff --git a/Chess-Challenge/src/Framework/Chess/Result/Arbiter.cs b/Chess-Challenge/src/Framework/Chess/Result/Arbiter.cs
index d98cca6..c2cd01b 100644
--- a/Chess-Challenge/src/Framework/Chess/Result/Arbiter.cs
+++ b/Chess-Challenge/src/Framework/Chess/Result/Arbiter.cs
@@ -84,20 +84,22 @@
             int numBlackKnights = board.knights[Board.BlackIndex].Count;
             int numWhiteMinors = numWhiteBishops + numWhiteKnights;
             int numBlackMinors = numBlackBishops + numBlackKnights;
+            int numMinors = numWhiteMinors + numBlackMinors;
 
-            // King v King
-            if (numWhiteMinors == 0 && numBlackMinors == 0)
+            // Lone kings or King vs King + single minor: is insuffient
+            if (numMinors <= 1)
             {
                 return true;
             }
 
-            // Single minor piece vs lone king
-            if ((numWhiteMinors == 1 && numBlackMinors == 0) || (numBlackMinors == 1 && numWhiteMinors == 0))
+            // Bishop vs bishop: is insufficient when bishops are same colour complex
+            if (numMinors == 2 && numWhiteBishops == 1 && numBlackBishops == 1)
             {
-                return true;
+                bool whiteBishopIsLightSquare = BoardHelper.LightSquare(board.bishops[Board.WhiteIndex][0]);
+                bool blackBishopIsLightSquare = BoardHelper.LightSquare(board.bishops[Board.BlackIndex][0]);
+                return whiteBishopIsLightSquare == blackBishopIsLightSquare;
             }
 
-
             return false;