Though the International Tennis Federation (ITF) very specifically delineates the requirements for tennis court dimensions, there is actually no reference to surface types in the rule book. As a result, today there are over 160 different types of tennis court surfaces, ranging from classic cement hard courts to more high-tech AstroTurf varieties. The ITF classifies each court surface into one of five groups according to its speed, with a category 1 court being the slowest, and a category 5 being the fastest. However, there are four generally recognized categories of court surface types: hard courts, clay courts, grass courts, and carpet courts.
Hard courts are the most common type of tennis court in the U.S., for they are relatively cheap to install and easy to maintain. They are made of cement and painted over with a paint that is mixed with sand to give it texture. Since the courts are completely flat, the ball will bounce predictably. Hard courts are considered faster than clay, but slower than grass, though the amount and type of sand mixed with the paint will affect the amount of friction that the ball encounters. The U.S. Open and Australian Open are both played on hard courts.
Clay courts are made from hard packed clay or sand, and are topped with loose sand or clay. These courts are the slowest, and can have a slightly less predictable bounce due to the texture variety from the loose topping. The surface is softer than hard court, so the ball won’t bounce as high. Furthermore, increased friction from the loose topping not only slows the ball down, but also increases spin. In fact, according to experiments performed by the ITF, a 67 mph shot will be reduced to 38 mph after just one bounce on a clay court (Lehrer). The French Open is played on clay courts.
Grass courts are well known largely due to the prominence of the Wimbledon tournament. The surface of this court type is similar to that of a putting green, for the grass is extremely short and grown on hard packed dirt. Though grass courts constantly change since they are made of living organisms, they are generally the fastest type of tennis court. The hard-packed dirt allows for a bounce speed similar to that of hard courts, but the presence of grass actually allows the ball to slide, reducing spin and causing the ball to bounce at a lower angle. In contrast to clay courts, a 67 mph shot will be reduced only to 45 mph, making it 15 to 20 percent faster than clay (Lehrer).
The final category of court surfaces is carpet. These courts are only used in indoor facilities, and are made of cement covered with a thin artificial turf-like carpet. The carpet will have a predictable bounce, but friction will slow the ball down. There are a variety of types of carpet surfaces available, each with slightly different properties.