At the U.S. Open, one of the Williams sisters was called for a foot fault during a doubles match. Her back foot was on the wrong side of the centerline. The next day I was playing doubles and my opponent was doing the same thing when he served, but he said he was told by his tennis pro that as long as his back foot is not past the centerline at the time of the serve he is fine. Was he?—David Manuel, Charleston, SC
Those rare centerline foot faults can be as difficult to explain as they are to call. The issues are time and place. The umpire at the U.S. Open was right and the tennis pro was wrong. Rule 16 says that the service motion must begin with the server behind the baseline "and within the imaginary extensions of the center mark and sidelines." Rule 18.d then adds that it's a foot fault if, during the service motion, the server touches "the imaginary extension of the center mark with either foot." If the server started her service motion with her foot touching the centerline extension, it would still be a foot fault, even if the offending foot had moved so it wasn't touching the extension at the time the serve was struck.
Except where noted, answers are based on the ITF Rules of Tennis and USTA's The Code.
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