Funny… if my opponent started with the 13-ball, I know I’m up against someone strong in 8-ball pattern runouts. You might want to consider why some of the posters like myself, Bob Jewett, Easy E, etc. think 13-ball is a wise choice. Lots of people have added great input as to why.It was not to imply you could not run it out. It's not a difficult layout and I'm confident I could get out regularly starting with any of the balls.
That said , if my opponent has bih and starts with the open ball in the middle of the table I consider it a strong indicator in my favor.