The spin attitude of a string depends on a number of factors that can be distinguished into two large “families”.
Group 1 (made of rigid and medium rigid strings working for snap-back)
- static and dynamic surface friction coefficient (i.e. from the outer layer of the rope)
- deflectional stiffness of the string which determines the return of the string into place
- reactivity / resilience peak – fast elastic return of the string.
Group 2 (made up of intermediate stiffness ropes working for ball-pocketing)
- medium and medium low static stiffness
- progressive plasticisation of the string. The string wraps around the ball and deforms plastically shot after shot in the same way that a race tyre uses its grip to stick to the ground.
Note: It is absolutely necessary to point out that the shape, the section of the string (e.g. pentagonal, hexagonal, octagonal) has a low incidence and is almost insignificant for the spin potential