Every Wednesday, this site delves into a rule or governing principle that determines how tennis is actually played. We are currently in the middle of a step-by-step explanation of each of the principles contained in “The Code,” which the USTA labels “The Player’s Guide to Fair Play and the Unwritten Rules of Tennis.” This week we focus on Principle 7, which is part of the ‘Call’ section.
It is good that the ball touches part of the line. If part of a ball touches a line, the ball is fair. A ball that is 99% out is still 100% good. A player may not call a ball unless he clearly sees space between where the ball hits and a line.
USTA Friend to Court 2025, The Code, Principle 7 (Completed)
This is one of the few places where The Code omits nuance. There is no sliding scale or compromise. Tennis calls are binary, meaning there are only two possible outcomes. The ball is good or it is out. A ball cannot be mostly out or essentially out. If any part of the ball touches the line, it is in.
That reality often clashes with our human urge to approach. A ball can land overwhelmingly outside the painted boundary and still cut the line by a millimeter. Even though it looks bad, according to the rules it is unequivocally good. The expression “A ball that is 99% out is still 100% good” is necessary because people want to round to their own advantage. Principle 7 explicitly prohibits that instinct.
It is worth noting that the last sentence of Principle 7, “A player shall not call a ball unless the player clearly sees space between where the ball hits and a line,” did not appear in the 2001 version. The code which we have used as historical reference in this series. Although the first sentence makes it clear that a ball hitting the line is good, it does not explicitly specify the visible space between the ball and the line for a call to be made. This omission left room for interpretation.
The newer language closes that gap. It shifts the burden of proof. The question is no longer whether the ball was probably off, but whether the player is clear saw it out. Without this visual confirmation, a call cannot be made. It’s a subtle but important shift.
The power of language is intentional. Anything softer would succumb to competitive pressure. Players are not allowed to call balls based on vibration. That’s not to say that players routinely cheat. Rather, it acknowledges something more human. Vision is imperfect. Our eyes deceive us. Speed clouds perception. This section of the Code is written around these limitations.
Principle 7 is built for real-world tennis. It assumes human imperfections. That’s exactly why visible space is needed before a ball can be called. Without that requirement, conversations under pressure may become malleable. By emphasizing visible space, the rule removes coordination and reduces the gray area where disputes can arise.
If you see clear separation, call it out. If you don’t, the game continues.
- Friend at Court: The Handbook of Tennis Rules and RegulationsUSTA, 2025
- Friend at Court: The USTA Handbook of Tennis Rules and Regulations, USTA, 2001. (On paper.)
For readers who may be new to the organized tennis landscape, the Friend at Court is the USTA’s compendium of all the rules governing sanctioned play in the United States. It contains the ITF tennis rules, USTA regulations, and additional guidelines specific to competition in this country. The Code is nested in the Friend at Court. That section describes the “unwritten” traditions, expectations, and standards of behavior that govern player behavior. The Code is the ethical framework that governs how recreational and competitive players conduct themselves every time they take the field.
#good