I don't know if this is true, but I heard at one time on the Euro Tour, it was part of the rules that the 2 ball cannot be placed in the same position twice. It must be placed in a different position everytime (until of course the cycle repeats itself).
Maybe someone can shed some light on that or verify it. I might be confused.
I think the only ball that is really significant is the 2 ball and where it lands. Breaks are random enough that beyond the 2 ball, spending even a small amount of mental energy on rack magic is a waste.