Updated: December 2017
Tennis Ball Reviews:Tennis balls are an afterthought to most amateur players, but they can make a real difference in your game. The professionals (guys and girls) use new balls almost all the time. Even when they practice they use quality, newer balls so they get the feel of hitting balls that will have the same feel when the match starts. The pros use new balls on every 7th game in their matches, so you can only imagine that the balls barely get worked in a bit and then they are discarded. I have been playing tennis for almost 20 years now and I still have a preference of Penn tennis balls over Wilson and the other barnds. Tennis balls come in a pressurized can that generally holds 3, but you can find some containers that hold up to 4 balls. When you open the top, a "psht" sound comes from the can as the pressure is released. The balls are now open to the air and will gradually lose their pressure, more so if you play with them a lot. Experts say their is a bounce test that everyone should use to consider if the balls still contain a decent amount of pressure to play with. Hold the tennis ball 100 inches above the ground and let it drop (onto concrete). If the ball bounces back up between 53 and 58 inches then it is still considered good. For the average player, balls should last about 6 to 8 sets of play. Most beginner to intermediate players don't hit the ball hard enough to really effect it's pressure status, but overtime the balls will lose pressure even if you aren't playing with them.
Another thing to consider is what surface you will be playing on. In America, most of us play on our local hard courts at the park or a tennis club. Much of the rest of the world plays on clay courts (where the weather is wetter), or even grass. Wimbledon is perhaps the most famous tennis tournament in the world and the surface is grass. The French Open, played just outside of Paris, France is held on the clay courts of Roland Garros. There are specific balls for each surface, which will make the play that much better. Penn ATP Tennis Balls are what the ATP tour uses in the biggest tournaments. These balls are often referred to as Penn Professional. The "Talk Tennis" section in Tennis-warehouse.com is a great place to get feedback on all the tennis ball types that exist.
It seems that everyone has their own preference as to which ball gives them the best feel and playability. Many consumers make a valid point that the pros play Penns, but to say those are the best is skewed since the pros do get to open new cans every 7 games and so they never know what it's like to play with balls that are a month old and slowly losing their pressure. Many of the comments left by players say the Dunlop/Slazenger and Gamma Tour XL balls are the best, although they are the most expensive as well. My personal opinion is that the Wilson balls are too hard when you first start playing with them, same goes for the Dunlop tennis balls. The Penn balls seem soft enough, yet I can get plenty of kick on my second serve and they are still fast enough to hit solid groundstrokes. I will say that Wilson balls tend to have better longevity and last longer, but while playing the "feel" of Penn balls is better. I usually switch out old tennis balls with new ones every 4 or 5 sets. The balls with "extra duty" felt are best for hard courts where the balls take a beating. We found a good review for the newer Prince Tour tennis balls on the Tennis Warehouse site. They are available in regular felt, extra duty felt, and high altitude w/ the extra duty felt. The balls were judged on feel, hardness, bounce, felt wear, and overall performance. The Prince Tour Extra Duty Felt seemed to perform best in the minds of the testers. The top brands in tennis balls are Penn, Wilson, Dunlop, Prince, Head, and Gamma. There are "practice" balls which are sold at most sporting goods stores like Dicks, Sports Authority, and probably in your local tennis shop. Practice tennis balls are good for kids just learning to hit the ball. Use them for drills and in tennis ball machines that feed balls to players. You can even buy pressureless balls which are ok for amateurs, but certainly not recommended for intermediate players or above.