Long Pimples Rubber
The pimples are facing out and are part of the playing surface. The pimples are longer which decreases speed and causes spin reversal on contact of the ball to the rubber. The pimples 'flex' under the balls weight and pressure and they produce deceptive returns that are difficult to read and respond to. Long pimples are often used by defensive players who require the control and spin reversal.
Thickness of Sponge
The thickness of the sponge will affect how fast the overall rubber will be, and also how much control it has. Thicker sponge is faster but has less control than thinner sponge. Most attackers use sponge of either 2.0mm or Max thickness (2.2mm), while many defenders use thinner sponge for the extra control. Most professionals use thicker sponge for increased speed.
No Sponge
It is possible to not use sponge at all with pimple out rubbers. This is classified as OX, using no sponge can be an effective tactic for those players who defend or twiddle their bats!
