As we discussed with
antispin rubbers, there are several factors involved in how a particular
long pimpled rubber works. Each long-pimpled rubber uses these factors differently, which is why no two long-pimpled rubbers play exactly the same way. The factors involved are listed below. Please keep in mind that this is my theory about long pimples, so I'm not claiming to be the last word on the subject.
Please keep in mind that in the items discussed below, the amount of spin we are talking about is much less than for inverted rubbers, but it is still significant.
(1) Amount of Grip of the Top of the Pimples.
All long pimpled rubbers have much less grip than normal rubbers, but this does not mean that they all have no grip. There is actually quite a difference in grips between different long-pimpled rubbers. The more grip they have, the more the player will be able to change the spin that you have put on the
ball. Some long pimples have smooth, almost glassy pimple tops that do not grip the ball at all, while others have rougher pimple tops that will grip more, and yet others have a smooth pimple top that grips.
(2) Amount of Grip of the Sides of the Pimples
The sides of the pimples can vary in the same way as the tops, with similar effects. Bear in mind that the sides do not have to be the same as the tops! The importance of this fact will be clearer after reading the next point below.
(3) Softness of the Pimples
The softer the pimples, the more they will tend to bend when the ball is hit, and the more the sides of the pimples will be able to touch and affect the ball. Stiff pimples will require more force before they bend, but once they do, they may bend quite a lot! A player using softer pimples will be able to produce more spin variation that a player using stiff pimples, provided that the sides of the pimples have some grip.
(4) Width, Density, and Shape of the Pimples
The wider the pimples, the less they will tend to bend, and thus the less the sides of the pimples will touch the ball. The more dense the pimples, the more contact can be made with the ball and the more the rubber will be able to affect the spin. The shape of the pimples is a bit more difficult to figure out. Most pimples are the same width at the bottom and the top, but not all. The pimples that I used to use were actually narrow at the bottom and wide at the top, like a funnel or ice cream cone. I believe that this tends to make the tops of the pimples get more contact with the ball while the sides of the pimples get less. Whether this is true, and whether it is even a significant difference is open to debate (I liked them though!). I assume the reverse would be true for a long pimpled rubber with a wide base and narrow top.
