55 Hook 14.5 Length 16.5 Breakpoint Shape

Manufacturer’s Intent: “The Defiant Edge will now anchor the new HP4 line for Roto Grip,” says Chris Schlemer, Roto Grip’s new marketing manager. “The major difference from the Defiant solid is the new pearlized Micro Bite coverstock, which clears the front part of the lane with ease, creating more direction change downlane. The Defiant Edge can be used as the first ball out of the bag, or if your Defiant starts to read too early.”

Core Design: The Paragon asymmetric core powers this new pearlized version of the original solid Defiant. The RG is low at 2.49, the differential strong at .054 and the intermediate diff influential at .017. Our testing saw nearly 7 inches of track flare with a 60x5.5x30 P3 dual angle drilling.

Coverstock: Providing the lane traction is the MicroBite pearl reactive cover. The factory finish is 1500 polished, and colors are a blending of red, black and electric blue. Response time off dry areas is quick and strong, and oil traction is slightly above average with factory shine. The Ra value is medium.

Test Results: The Defiant Edge is Roto Grip’s premier pearl asymmetric for medium to heavy oil volumes. The core and cover are matched perfectly, as we rarely experienced any over-skid on heavier fresh oil or through oil carrydown. The aggressive nature of this ball allows for bowlers to play inside the oil line and keep it tight on line or send it to tickle the friction line. We saw 2 to 3 feet more length than a like-drilled Defiant (3000 grit solid), coupled with a more angular move off friction. As for motion shape, we saw little angularity change from our pin positioned above the fingers compared to below. In fact, both layouts provided a quick and angular move when leaving the oil, as the ball finished with above-average continuation through the deck.

When to Use: Use on any fresh medium to heavy oil volume on either Sport or house-type variations. The Defiant Edge sanded to 3000 grit will play both earlier and stronger, like the original Defiant. At 3000, the main difference between the two balls was a touch cleaner push and an eyelash quicker response off friction for the Edge. With the Defiant clearly being the big boys on the block, speed-dominant and/or rev-challenged players will feel considerable love for both. Roto Grip rates the Defiant Edge as 83/75 MH with its new Guts-Grit-Grime rating system. This is below the Defiant and above the Critical Theory (August 2011), which are the other two balls in the HP4 (Hooking Potential 4) line.