Ball on the Line (Line Rule)
Also known as: line ball, ball touching the line, ball on the line, line call rule, clay court ball mark, ball mark on clay, hits the line, lands on the line, ball lands on the line, ball hits the line
A ball that touches any part of a line is in. Under ITF Rule 12, the line counts as part of the court it marks. In matches without officials, The Code says a ball is good unless you clearly see space between where it landed and the line.
ITF Rule 12 is short. If a ball touches a line, it is regarded as touching the court bounded by that line. A serve that clips the service line is in, and a ball that clips the baseline is in. Court measurements are made to the outside of the lines (Rule 1). The lines are part of the court. As The Code puts it, a ball that is almost entirely out is still good if it touches the line.
In unofficiated play, each player calls the balls landing on, or aimed at, their own side of the net. The Code says a player should not call a ball out unless they clearly see space between where it hit and the line. Any ball that cannot be called out with certainty is good. A player cannot claim a let because they did not see the ball. Out calls must be prompt and audible or visible.
Clay courts leave marks, and The Code has a rule for them. If any part of the ball mark touches the line, the ball is good. If only part of a mark can be seen, the missing part is on the line. A player does not have to show the mark to the opponent. The opponent may not cross the net to inspect it. When officials are present, they take over the calls they are assigned.
Tips by skill level
Remember the line from The Code: a ball 99% out is 100% good. If you cannot see space between the ball and the line, play it.
On close balls near your lines, watch the ball land rather than the opponent. On clay, take a careful second look at marks near the line before calling.
Example
A deep forehand lands with its edge just catching the baseline. The opponent sees no space between ball and line, calls it good and plays on. On clay she would check the mark, and any part touching the line means the ball is in.
Why it matters
Line calls decide points, and arguments over them spoil matches. Knowing that the line is in, and that doubt goes to the opponent, settles most disputes before they start.
Common mistakes
- Calling a ball out because most of it landed outside the line
- Calling out a ball you did not clearly see instead of giving it to your opponent
- Offering to replay a point because you were unsure. An unsure call is good.
- On clay, ignoring a mark that only partly touches the line
Frequently asked questions
Is the ball on the line in or out in tennis?
In. Under ITF Rule 12, a ball that touches any part of a line counts as landing in the court. A ball 99% out is still 100% good.
Is a serve on the line in?
Yes. The service line, center service line and singles sideline all count as part of the service court. A serve that touches any of them is good.
How do you call a ball mark on clay?
Under The Code, if any part of the mark touches the line, the ball is good. If only part of the mark shows, the missing part is on the line. You do not have to show your opponent the mark.
Sources
Related terms
- Line Calls Without Officials (The Code)In matches without officials, each player calls the balls on their own side of the net, and any doubt goes to the opponent. Calls must be prompt and clear, out loud or with a hand signal. If an opponent makes a pattern of bad calls, The Code says you may contact an official.
- Challenge System (Line Calls)The challenge system lets a player dispute a line call using electronic ball-tracking. Only a limited number of unsuccessful challenges are allowed per set.
- Let (Serve Rule)A let is called when a serve clips the net cord and still lands in the correct service box. The point is then replayed with no penalty to the server.
- Foot FaultA foot fault occurs when a server's foot touches the baseline or crosses into the court before contacting the ball on the serve. It results in a fault.
- Tennis ScoringPoints in a tennis game go love (zero), 15, 30, 40, then game, and the server's score is called first. At 40-40, called deuce, a player must win two points in a row to take the game. The first to six games wins the set by two, usually with a tiebreak at 6-6, and matches are best of three or five sets.
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