ITF Ball Types

One of the most shocking revelations of our steady march through the rules of tennis is that there are four types of tennis balls approved for regulation play. The types are rather unimaginatively named: Type 1 (Fast), Type 2 (Medium), Type 3 (Slow), and High Altitude. Appendix I of the ITF Rules of Tennis contains a table with the conformance requirements for weight, size, rebound, and deformation for each of these ball types.

High altitude balls were added to the ITF standard in 1979. For anyone who has ever played at altitude, in general tennis balls sail off the racquet and bounce significantly higher. The introduction of the high altitude ball allows players like me to consistently hit balls 3 feet out as opposed to over the fence when playing in the mountains.

Type 1 and Type 3 tennis balls were officially codified in 2002. Approval for the new ball types actually came at the 2001 ITF annual meeting which was held in Cancun, Mexico. From this I came to the obvious conclusion that tequila was heavily involved in the decision. Currently there are exactly two ITF approved Type 1 balls and zero Type 3 balls.

Just last week, YouTube served me a video illustrating tennis ball conformance testing machinery. That video included some clips of the 2012 ITF Guide to Products and Test Methods document, including a page that illustrated the bounce trajectories of three of the four types of balls. Sadly, that diagram is no longer in the current 2021 version of that document.

The screen grab of that image is embedded within the headline photo of this post. It provides a little more information about how the ITF originally envisioned these new balls would work. It’s fascinating stuff. It also generates a high altitude ball mystery that will be the topic of next week’s Rules of Tennis post.