Began bowling again after a 20+ year layoff and I'm not up on all the lingo, but I feel obligated to give a positive review to the 2 AMF balls I've acquired in the last few months. Purchased a Columbia Scout Reactive, which was a real dog for me ( 250lbs, avg. revs, high ball speed.) It left me no room for error and very discouraged by my performance. The house conditions the lanes about 30 minutes before our league starts, so there is a fair amount of oil. The Angle Evolution was on a closeout sale at a local pro shop, so I picked it up. First time out, I matched my season high that I threw with the Scout. Within a few weeks, my avg had improved by 50+ pins. 600 triples are now a regular occurance, and I have several 250+ games under my belt. Under very dry conditions, the ball breaks a bit too hard, but under most oil condition minor footwork adjustments take care of things. Picked up a Nighthawk Torque Pearl brand new from an internet auction - the only reason I bid on it was because the ball is basically the same as the Angle with a different coverstock - that ball is great as well, especially under slightly drier conditions. If you find either one lying around, pick 'em up! I couldn't be happier with them.