I took my Defiant Soul out for the real test today. I bowled on a 39' house shot. I'm a tweener rev rate around 300, ball speed 15 mph. I first took my Defiant and played 12 to 5 and it looked very good with a strong arc to the pocket. So I then took my Defiant Soul and played the lanes in the same area. Super clean through the fronts with a great big move to the pocket. Talk about hit, this ball will slap pins all over the place. I'm really impressed with this ball. I kept on moving left and never lost my backend motion. The longer I kept it in the oil, the stronger and more angular the backend reaction was. As always, Roto Grip equipment is so easy and acceptable to surface changes. I used some Reacta Clean and Reacta Shine on this ball and it just made it cleaner with more backend motion. It just got stronger and stronger. This ball made me look like I had a lot more hand. I also used it on a 39' sport pattern and took it back down to the box finish. I threw it around 9 out to 6, 7 and the ball didn't disappoint. Clean through the front and strong backend. I can see this ball traveling a lot with me to tournaments. But I don't think you could go wrong with the Defiant Soul for almost all house patterns.