public static Position GetBestMove(GameBoard Gb, Slot P, Difficulty Difficulty)
        {
            Position? bestSpace = null;
            List<Position> openSpaces = Gb.OpenSquares;
            GameBoard newBoard;

            for (int i = 0; i < openSpaces.Count; i++)
            {
                newBoard = Gb.Clone();
                Position newSpace = openSpaces[i];

                newBoard[newSpace.Row, newSpace.Col] = P;

                if (newBoard.Winner == Slot.Open && newBoard.OpenSquares.Count > 0)
                {
                    Position tempMove = GetBestMove(newBoard, ((Slot)(-(int)P)), Difficulty);
                    newSpace.Mark = tempMove.Mark;
                }
                else
                {
                    if (newBoard.Winner == Slot.Open)
                        newSpace.Mark = 0;
                    else if (newBoard.Winner == Slot.X)
                        newSpace.Mark = -1;
                    else if (newBoard.Winner == Slot.O)
                        newSpace.Mark = 1;
                }

                if (bestSpace == null ||
                   (P == Slot.X && newSpace.Mark < ((Position)bestSpace).Mark) ||
                   (P == Slot.O && newSpace.Mark > ((Position)bestSpace).Mark))
                {
                    bestSpace = newSpace;
                }
            }

            return (Position)bestSpace;
        }