I have been bad in recent years about changing balls. I think the correct answer really depends on what is happening on the lanes. A minor change of line, hand position or targeting is probably the best first answer. However, that all depends on what is going on. If you were rolling proactives and the ball is rolling out, obviously a ball change would be my first change, then see where to go from there. On the opposite ends is the ball is skidding all the way through the pin deck, well something with some surface might be in order. All goes back to reading what is going on and giving it your best shot. There sure isn't a one answer. I have learned the hard way in the last year or so, that playing ball tag is not the answer to high scores.