Butterfly Rubber Performance Index
*The performance index for Butterfly rubbers has been revised from February 2023 in line with improved measurement methods.
Speed: Describing the rubber's effect on ball speed in a relative manner measured/evaluated by Butterfly's unique tests. The higher the value, the faster the speed and the more suited it is to offensive play. On the other hand, the lower the value, the slower the speed, and the more suited it is to defensive play.
Spin: Describing the rubber's effect on the amount of spin generated on the ball in a relative manner measured/evaluated by Butterfly's unique tests. The higher the value, the greater the amount of spin produced. On the other hand, the lower the value, the easier it is to generate balls without spin.
Arc: Describing the ease of generating a high degree of trajectory on the path of the ball in a relative manner measured/evaluated by Butterfly's unique tests. The higher the value, the more likely it is that the ball will travel in the same direction as the racket swing during topspins. The lower the value, the lower the ball trajectory gets.
Stability: Exclusively for Long pimpled, Pimples-out (without sponge) and Anti-spin rubbers. The stability (Probability of returning balls) during chops, pushes, punches and blocks is evaluated on a 10-point scale. "Total" is the average value of evaluation during each technique.
Variation: Exclusively for Long pimpled, Pimples-out (without sponge) and Anti-spin rubbers. The variation (Probability of unexpected spin/shot) during chops, pushes, punches and blocks is evaluated on a 10-point scale. "Total" is the average value of evaluation during each technique.
* Speed, Spin & Arc: (Pimples-out) is for Pimples-out rubbers, and unless otherwise specified, it is for Pimples-in rubbers.
* Stability & Variation: The evaluations by the Butterfly Research and Development Department. Use it as a guide to select the Long pimpled, Pimples-out (without sponge), and Anti-spin Rubbers.
* The figures and evaluations for the properties of Butterfly rubbers are based on tests carried out by Butterfly's Research and Development Department up to February 2023. Average weights are based on production up to February 2023. The thickest sponge thickness line-up in each rubber is used for testing and average weight measurement.
