Court Pace Index Explained
What Is the Court Pace Index and How Is Tennis Court Speed Measured?
Tennis court speed is not left to players' impressions. The ITF, the sport's governing body, measures surfaces with a Court Pace Rating and sorts them into five categories, from slow to fast. The number is often called the Court Pace Index, or CPI, in commentary and fan analysis.
The five pace categories
Each classified surface gets a Court Pace Rating (CPR), and that rating decides its category. According to the ITF's scale:
| Category | Description | Court Pace Rating |
|---|---|---|
| 1 | Slow | 0–29 |
| 2 | Medium-slow | 30–34 |
| 3 | Medium | 35–39 |
| 4 | Medium-fast | 40–44 |
| 5 | Fast | 45 and above |
Clay courts usually sit in the slow categories and grass in the fast ones, but hard courts can be built to almost any pace. That is why two hard-court tournaments in consecutive weeks can play very differently.
How the ITF measures a court
The rating comes from a standard test. The ITF's guide to test methods for tennis court surfaces describes the procedure: a ball-projection device fires a ball at the surface at a set speed and angle, and the equipment measures how much speed the ball loses and how steeply it bounces off the court. Friction slows the ball and makes it bounce higher on a slow court; on a fast court, the ball skids through and stays low.
The ITF publishes a list of classified surfaces with their category, so manufacturers, clubs and tournaments can compare products on the same scale. Surface pace and ball speed are separate things: the ball type, the air temperature and altitude all change how fast a match feels, even on the same court.
Why tournaments care
Organisers use the pace category to choose a surface for their event and to keep conditions consistent from year to year. A tournament that wants long rallies asks for a slower court; an indoor event in the autumn swing may prefer a quicker one. The category is also useful for clubs laying new courts, because it tells members in advance how the surface will play.
The pace category does not decide who wins. It shifts the balance between serving and returning a little, and players adjust. If you want the official rating of a particular surface, check the ITF's classified surfaces page, which is updated as new products are tested.
This guide is general information. Clubs, tournaments and manufacturers set their own rules and change them; check the official source named in the text.
