Tennis Court Lines

Whether you’re playing tennis at the local park or in a tournament setting, knowing your court lines is essential to making informed decisions and improving your game. There are a few key lines that make up the boundaries of a tennis court that should be known by all players, and understanding them can help prevent confusion about whether a ball hits or misses a line during play.

The Service Box

A vital launching pad for serves, the service box outlines the area that players can serve into during matches. This area is crucial for limiting the opposing team’s opportunities to score points by hitting winners or pushing them back behind the baseline. To determine the service box’s dimensions, simply measure from the center point of the singles court sideline to the net center line on each side. Then, connect the two points across the court to create a rectangle with equal sides. The width of the service line should be between 1 and 2 inches wide, but it must not be wider than 4 inches.

Doubles’ Sidelines

Not labeled in the diagram above, the doubles sidelines demarcate the limits of a tennis court during doubles match play. These outermost lines run parallel to the singles court sidelines and extend the playing field to accommodate two extra players. Balls that land beyond the doubles’ sidelines in a singles match are considered out of bounds.

The Baseline

The baseline is the most important line for determining if a shot is out of bounds during a match. It defines the area that you cannot hit a ball across when serving in deuce or ad court, and helps to limit the amount of time your opponent has to prepare for your serve. In addition, the baseline can also help you judge how deep to hit your groundstrokes when attempting to attack an opponent’s position.

Other Lines

There are several other tennis court line that can be found on a tennis court, but most players don’t need to pay attention to them during practice or a casual game. The doubles alley, for example, is a strip of court between the singles sidelines and the net posts that is only considered “in” during doubles matches.

Another important line is the centre mark, which must be drawn at 21 ft (or 6.4 meters) from each side of the net and equidistant to both singles court sidelines. Typically, the centre mark and service line should be about 2 inches (or 5 cm) wide, so that players can quickly and accurately judge if a ball hits or misses the lines during a rally. In professional matches, technology like Hawk-Eye can resolve disputes about a ball’s bounce position on a line, eliminating the need for player and line judge disagreements during close calls. However, the centre mark does not appear on most courts used for recreational purposes. This is because it makes it difficult for recreational players to see the line from their viewing position on the court.