A ball that goes straight and hooks a ton on the last 15-20 ft or so is good for going around a hang spot or on lanes where the ball is burning up early. If you are experiencing what looks like carrydown and the ball isn't moving on the backend, throw this type of ball and see if it is really carrydown or the ball is burning too quick on the back end.
What kind of line are you trying to play? What kind of shot is it, does the ball hook early and hard, is there oil in the middle, how far does the ball go down the lane before it hooks, and what type of equipment are you throwing now?