How can I be certain if a serve is long? If a serve bounces an inch behind the service line, it’s impossible to see the space because the ball blocks my view. I usually just make my best guess and err on the safe side.

—Michael-John van Rhyn, NJ

You can’t just guess on calls. The Code, #8, states that “any ball that cannot be called out is considered to be good.” And The Code, #7, commands that “a player shall not call a ball out unless the player clearly sees space between where the ball hits and the line.”

Except where noted, answers are based on the ITF Rules of Tennis and USTA's The Code.

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