Regular duty vs Extra duty balls?

[Jack2010]

This may be a dumb question but what is really the difference between regular duty and extra duty tennis balls? Are they really that different? They don't seem all that different to me

Jack

 

[mikeler]

"Answer: Extra duty felt is made for hard courts, which wear away the felt quickly. Regular felt is better on clay courts, which wear the felt less but tend to fluff it up. Extra duty felt gets too fluffy on clay courts. Regular felt gets too worn on hard courts."

From http://tennis.about.com/od/tennisballfaq/f/faqballs018.htm

 

[HitItHarder]

In theory, the Extra Duty version of that brand of ball will have a slightly thicker rubber core wall and a heavier duty version of the felt. The idea is that the ball will last a little longer on Hard courts.

Some people believe the Extra Duty versions are a little harder and heavier as a result. I really can't tell that big of a difference in feel (I actually prefer a slightly heavy ball), but I have noticed that the Extra Duty versions seem to keep their bounce a little longer.