Bowling balls

RG (radius of gyration) tells how far the mass of a ball sits from its center. A low RG, below 2.50, revs up early and rolls sooner. A high RG, 2.55 and up, keeps its energy for longer down the lane.

The differential is the gap between the highest and lowest RG of the core. The higher it is, the more the ball can flare and the more it can hook. Below 0.035 is low, 0.050 and up is high.

A symmetric core gives a smooth, predictable arc. An asymmetric core has an intermediate differential as well, so it reacts more sharply at the breakpoint and gives the driller more layout options.

Solid reactive covers grip the most and suit medium to heavy oil. Pearl covers skid further and turn harder on medium to light oil, hybrids sit in between. Urethane gives a controlled, even motion on short or dry patterns, and plastic goes straight: the spare ball.

Straight from the websites of the manufacturers. We check them regularly, so new balls show up soon after their release, and retired balls stay in the catalog.

Yes. With a free account you keep your whole arsenal in BowlingMaat: which balls you own and at what weight, their layout, surface and maintenance. Logging games is not needed, but if you do, you see your average per ball.