Line Calls: Principle 5 of The Code

Every Wednesday, this site examines a rule or governing principle that shapes how tennis is actually played. This post continues the ongoing series on the principles from The Code. This week, we are moving from the section covering the service procedures to a more controversial topic. It is one that, more than any other, is the flashpoint of the vast majority of drama in self-officiated tennis: making calls. Principle 5 is deceptively short and straightforward. This will be a rare “one and done” post for a single numbered principle. However, there are 17 additional principles to come that also address when players make calls in the sport. We’re going to be in this section of The Code for months.

Player makes calls on own side of net. A player calls all shots landing on, or aimed at, the player’s side of the net.

USTA Friend at Court 2025 , The Code, Principle 5 (Complete)

Principle 5 establishes the baseline expectation from which all other line calling principles flow. It is short, direct, and unchanged from the 2001 version of The Code that we have been leveraging as a more verbose reference. In effect, this principle answers a simple question before anything more complicated is addressed. Who is responsible for making calls? The answer is unambiguous. Players are responsible for making line calls on their own side of the court.

Before The Code wades into good faith, benefit-of-the-doubt, partner consultation, overrules, and the many ways calls can go wrong, it locks in a single premise. Self-officiated tennis only works if players accept ownership of their calls. Without that baseline, no amount of procedural detail matters.

That is why Principle 5 stands on its own. It establishes ownership before addressing behavior. Every principle that follows assumes this responsibility has already been accepted in good faith. What comes next in The Code does not redefine who makes calls. Rather, it explores what happens when that responsibility is stress-tested.

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Since this post is uncharacteristically short, I will take the opportunity to pull the curtain back slightly on a couple of factors that have influenced my plans for this series.

First, I was hoping that the USTA would release the 2026 edition of the Friend at Court before we moved into the Making Calls section. We will be in this section of The Code for quite some time. When the new edition of the Friend at Court is released, I plan to pause the sequential march through The Code to highlight and break down any new or revised rules that warrant attention. Given the timing, that interruption will likely fall squarely in the middle of the line-call principles. That is not ideal, but it feels like the right choice. At that time, I will switch to the 2026 edition of The Code and backtrack to the principles we have already covered, if any of those have been updated.

Second, I have previously mentioned that I have been looking for the original publication of The Code. While reorganizing my tennis books over the holidays, a pamphlet version of The Code fell out of a used book I had picked up some time ago and never gotten around to reading. This edition carries Nick Powel’s 1981 copyright and is dated as revised in January 1995. That is six years earlier than the 2001 reference version I have been using. I am still looking for the original 1981 edition and really any other versions of that document, as I am sincerely interested in tracing the history. If anyone comes across these artifacts, I will cheerfully trade Fiend at Court swag for them.

That pamphlet version is dramatically different from The Code that is currently in the 2025 USTA’s Friend at Court. Different enough that I will not attempt to use it as a reference point while working through the current principles. Instead, once this current series is complete, my intention is to step back in time and explore that much earlier artifact in its own separate examination of tennis’s behavioral standards.

All of that kind of buries the lead over how thrilled I was to discover that I had a much older version of The Code in my possession all along. This series would likely have started out very differently.

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1. Friend at Court: The Handbook of Tennis Rules and Regulations, USTA, 2025
2. Friend at Court: The USTA Handbook of Tennis Rules and Regulations, USTA, 2001. (Hardcopy.)

For readers who may be new to the organized tennis landscape, the Friend at Court is the USTA’s compendium of all rules governing sanctioned play in the United States. It includes the ITF Rules of Tennis, USTA Regulations, and additional guidance specific to competition in this country. The Code is nested within the Friend at Court. That section outlines the “unwritten” traditions, expectations, and standards of conduct that guide player behavior. The Code is the ethical framework that shapes how recreational and competitive players conduct themselves every time they step onto the court.