private int[][] copyBoard(Board b) {
		int[][] oldBoard = new int[8][8];
		for (int rank = 0; rank < b.board.length; rank++) {
			for (int file = 0; file < b.board[rank].length; file++) {
				oldBoard[rank][file] = b.board[rank][file];
			}
		}
		return oldBoard;
	}