Going heavier is hard decision to do. I would throw some house balls or a friends ball with the target weight you want before buying something. About getting a high performance ball, you don't really need one unless you want a ball that pairs up with what you want to do with it. You should know the normal conditions you bowl on - light, medium, heavy oil and if you play on fresh or burnt up lanes. You should find a ball that is meant for the oil condition you are playing on and how you throw the ball. If you throw the ball around 18+ with a excessive revs you will need a ball that is more aggressive than say a stroker. My last ball I bought was a Brunswick meanstreak which is made to have much length and a big back end for medium to dry oil. Strangely the ball is very versatile. If I drop my speed down the ball will cross the whole lane and cut back in the pocket, or I can throw it hard to make it have a more traditional hook to. I still have yet to play on a fresh condition with it, but it's my favorite ball at the moment. Although the ball that works best for me is a cheap 80 dollar polar ice, because it works really well on dry lanes, and I can throw it on just about any oil pattern.
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