1st-Service has developed the following USED BALL Grading System based on our experience testing thousands of used balls.
REBOUND is measured as the peak height the bottom of a ball reaches on it's first bounce off a smooth concrete surface, when dropped from 100". The test is performed under controlled conditions: Temp. between 18°C and 22°C, and Relative Humidity between 55% and 65%. These follow rebound test guidelines set by the International Tennis Federation for game play*.
GRADE REBOUND fr 100" DESCRIPTION
A 55.5” - 58” Best bounce - “Warmed Up”
C 50” - 53” Low bounce - “for quick starters”
B 53” - 55.5” Good bounce - “Broken In”
D below 50” Dead, but durable and clean –“great for dogs”
F below 50” Dead and/or dirty – “not fit for play”(includes "dot" balls)
All rebound grades that we sell are clean with minimal to nominal cover wear. Some may have player markings. The lower the grade the more worn the felt cover may be, although even some B and C grade balls may look brand new.
All F grade balls get re-purposed/recycled, Most of them get donated to schools for placing on chair/desk legs to quiet classrooms, while some get sent to Project Green Ball and other recyclers to be converted into Tennis surfaces. We sell Grade D balls to the general public for dog toys and other innovative commercial re-use applications, but non-profits only pay shipping costs and get the balls for free.
Glenn C. Sterkel
South Elgin, IL 60177
Phone: (630) 675-0250
* Our tests do not certify tennis balls for ITF sanctioned play. We only follow their rebound test specifications to provide our customers a consistent basis for comparison between USED tennis balls and fresh new balls.