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FifthSet

GlossaryTechnology

Hawk-Eye

The camera-based ball-tracking system behind electronic line calling; since 2025 it has replaced line judges on the ATP Tour and at three of the four majors.

AlsoHawk-Eye Live, electronic line calling, ELC, ELC Live, challenge system, line-calling technology, hawkeye

Published

Hawk-Eye is a system of cameras around the court that tracks the ball and computes where it landed. For years it powered the challenge system: line judges called the lines and a player could ask for a replay of a close call, with a limited number of unsuccessful challenges per set. The US Open was the first major to use it, in 2006. The current form is live electronic line calling (Hawk-Eye Live and rival systems), in which the technology makes every call in real time through a recorded voice and there are no line judges at all.

When you see it

On the ATP Tour, live electronic line calling has been mandatory at every event since 2025, on every surface including clay; the chair umpire remains, the line judges do not, and there is nothing left to challenge. Among the majors, the Australian Open went fully electronic in 2021, the US Open the same year, and Wimbledon from 2025, ending 147 years of line judges. Roland-Garros still uses line judges and ball marks on the clay. Close calls are replayed on the video screen automatically. The net-cord let is a separate call.

Rule basis

ATP Official Rulebook, Chapter VII (Electronic Review, Live Line Calling): "There shall be no line umpires. All lines shall be called using the Live ELC System approved by ATP." The rule also covers a system failure: the chair umpire calls, or the point is replayed.

Related terms

  • Let · A call that stops the point and has it replayed; most often a serve that touches the net and still lands in the service box.
  • Grand Slam · One of the four majors (Australian Open, Roland-Garros, Wimbledon, US Open) or, strictly, the feat of winning all four in one calendar year.
  • Masters 1000 · The nine biggest ATP Tour events below the Grand Slams, worth 1,000 ranking points to the winner; seven now run for 12 days with 96-player draws.

Sources

Material claims in this article are supported by the following sources.

  1. 01Wikipedia · Hawk-Eye (tennis sections: challenge system and Hawk-Eye Live)retrieved
  2. 02ATP Tour · Electronic Line Calling Live To Be Adopted Across The ATP Tourpublished · retrieved
  3. 03Tennis.com (Associated Press) · Electronic line calling to be implemented at every ATP Tour event by 2025published · retrieved
  4. 04Sky Sports · Australian Open: In a Grand Slam first, all courts will feature electronic line callingpublished · retrieved
  5. 05Sky Sports · US Open: Electronic line-calling will be used on all competition courts at Flushing Meadowspublished · retrieved
  6. 06Al Jazeera (agencies) · Wimbledon to replace tennis line judges with electronic system from 2025published · retrieved
  7. 07ATP Tour · 2026 ATP Official Rulebook, Chapter VII: The Competitionretrieved