Differences in High Altitude Tennis Balls?

What is the difference between regular and High Altitude tennis balls? How are they made
- Kurt (age 59)
Taos, New Mexico

There must be a lot of tennis aficionados out there because this is a frequently asked question on our website.   Taos New Mexico, at almost 7,000 feet above sea level, certainly qualifies for high altitude balls (greater than 4,000 ft).  Basically they are a tad bigger than regular balls and have an internal pressure only slightly above that of atmospheric.
Rather than go through all the details here let me point you to the official USTA answer:


LeeH

(published on 09/16/2011)