The drop test shows how the rebound height of the Pro changed with surface temperature. But how does the Pro's bounce change during actual play, as its surface temperatures changes?
To partially answer that question, a drive test was done on the Pro at four different surface temperatures: 114f, 103f, 93f, and 84f.
For each drive, the starting point was at the back line of the service box, about 3 feet high. The front wall contact height was 6.0 feet. The first bounce on the floor was at the back line of the service box. This allowed each drive approximately the same flight path and velocity off the front wall, until the ball took its first bounce. (Much thanks to Cornell Men’s squash coach Scott Stoneburgh for his accurate driving) .
A video camera recorded the flight path of the ball after the first bounce on the floor. Tape was placed on the sidewall as reference points. The horizontal strips of tape are 1 foot and 2 feet off the floor respectively. A digital snapshot was taken of the right wall behind the service box, and the flight paths from the video were overlaid.
The 114f Pro is indicated by the black line, and comes way off the back wall. The 103f Pro is indicated by the green line, and comes off the back wall less than the 114f Pro. The 93f Pro is indicated by the blue line, and barely comes off the back wall. The 85f Pro is indicated by the red line, and dies before the back wall.
The above illustration, while helpful, only shows part of what happens during play. How a ball behaves during play is an aggregate of how it bounces off of every surface it contacts: the racket, front wall, and depending on the shot, the floor, the back wall and one or more side walls. A decrease in bounce means a decrease in velocity from each surface.
The lower the surface temperature, the harder Scott had to hit the ball to perform the drive test. Scott had to hit the 103f Pro harder than the 114f Pro, in order to get it to take the same flight path before it took its first bounce on the floor. Otherwise the 103f Pro would have taken its first bounce closer to the front wall.