Electronic Line Calling and Call Challenges in Tennis
Line calling is probably the most frustrating thing in tennis. Was the ball in or out? All tennis players recognize this issue. When a ball lands near the line with fast speed, it can be almost impossible to accurately call it in or out. Junior, recreational, and even lower level professional tournaments face the issue of in-accurate line calling, because the human eye simply isn’t precise enough. That’s where electronic line calling steps in.
On the ATP and WTA tours, electronic line calling systems like Hawk-Eye have become the standard. These systems have offered line calling for pro matches for years. Recreational, club, and lower level pro level matches still rely on human judgment, which, as we all know, isn't always flawless. If there are line calling mistakes in matches with a chair umpire and several line judges, how are players expected to accurately call the lines while playing?
What is Electronic Line Calling?
Electronic line calling is a modern solution that eliminates the uncertainty of traditional line calls in tennis. At its core, it replaces human judgment with automated, technology-driven accuracy. These systems rely on advanced tracking methods, most commonly using high-speed cameras, sound triangulation, or a combination of both. Zenniz, for example, uses both sound and video to accurately detect the ball’s exact landing spot in real time. Beyond just getting the call right, electronic line calling helps players stay focused, reduces match disputes, and brings a new level of fairness to the game.
A Fair and Stress-Free Tennis Experience with Electronic Line Calling
Technology in tennis helps players enjoy accurate calls, making the playing experience both fair and stress free. In the past few years, electronic line calling systems like Zenniz have emerged. Zenniz offers players accurate line calls at a fraction of the price of the systems used at the pro-tour, making it a perfect choice for clubs who want to organize tournaments where matches flow without disputes and where matches are 100% fair for all players. Zenniz sets a high standard for electronic line calling, offering a solution for all types of matches, from casual games to competitive tournaments.
👉 See how Zenniz was used at the Finnish National Tennis League.
Electronic Line Calling Revolution
The world of tennis has been looking for a reliable and accessible system for making accurate line calls. That’s where Zenniz steps in.
Our mission? To bring the precision and fairness of electronic line calls to players of all levels, not just the pros. Right now, many clubs and tournaments still depend on human line calls. But that's changing fast.
✅ No more arguments
✅ No more uncertain calls
✅ Just accurate and automatic decisions
User-Friendly and Reliable Line Calling
Zenniz is designed to be easy for players, coaches, and tournament organizers to use. Our electronic line calling system integrates seamlessly into matches with just a few simple steps. Once activated, it automatically monitors every shot and makes precise line calls.
It's easy to set up for matches. No training required. Just turn it on, start playing, and let the technology do the rest.
Zenniz can be used in matches played with or without umpires. At tournaments where Zenniz has been used the feedback has been great. Players, umpires, and parents all love the system and feel like it makes the match experience more relaxed and better.
📢 “The experience with Zenniz is just completely 100% fair play.”
— Goran Novakovic, CEO of TEN-PRO
Proven Accuracy with Zenniz Electronic Line Calling
Zenniz is built on patented electronic line calling technology that delivers consistent accuracy across all levels of play. The system has been tested and trusted at national and international junior tournaments, where reliability matters.
Continuous updates and refinements ensure Zenniz stays at the leading edge of tennis tracking systems. With a low margin of error, players and organizers can rely on every call made by Zenniz.
👉 Read how Zenniz was used in the 2024-2025 Finnish Tennis League.
How Electronic Line Calling Works: Sound Triangulation & Cameras
What makes Zenniz different from traditional automated line calling tools? It uses a combination of two powerful technologies:
Sound triangulation captures the precise moment the ball hits the surface.
Four strategically placed cameras track the ball’s position from multiple angles.
This dual tracking approach allows Zenniz to make quick decisions with accuracy, even for fast shots and close calls. By combining sound and video data, it ensures every call is made with precision.
👉 Read more about how tennis tracking with Zenniz works.
Challenging Line Calls with Zenniz
With Zenniz, challenging a line call is as simple as it is for the pros:
Your opponent makes a call you wish to challenge.
Express your intent to challenge.
Go to the Zenniz device with your opponent and press the "Challenge" or "Shot Replay" icon.
A list of your previous shots will appear. Find the shot that was challenged.
Continue playing. The amount of challenges left will update based on if the line call changed the call or not.
The process is easy and resolves line call disputes in a few seconds.
The New Standard for Fair Matches with Electronic Line Calling
Zenniz doesn’t just add technology to tennis. It raises the standard of how matches are played. By eliminating guesswork and human error, it creates a match environment that’s more fair, focused, and enjoyable.
Players can trust that every call is right. Coaches can focus on strategy. Organizers can run smoother events. All thanks to one consistent, reliable system.
Are you ready to experience the future of tennis? 🎾