Free dataset

Which tennis tournaments use electronic line calling?

Name: Electronic line calling in professional tennis, by tournament and season (2017 to 2026)
Creator: Live Tennis API
Published: 2026-10-22
License: https://creativecommons.org/licenses/by/4.0/

As of 22 October 2026, every ATP Tour event has used live electronic line calling, with no line judges, since the start of 2025. The Australian Open (2021), the US Open (2021) and Wimbledon (2025) also call every line electronically. Roland Garros is the one Grand Slam that still uses human line judges, and it kept them in 2026.

That answer comes from a free dataset we publish under CC BY 4.0. It has 278 rows, one for each event, season and tour, from 2017 to 2026. Every row with a known value links the page that supports it.

Download the CSV See the project on GitLab

When did each Grand Slam go fully electronic?

Each year is the first season with electronic calling on every court and no line judges, unbroken up to the latest edition. Under it is the source the dataset cites for that row.

The season each Grand Slam went fully electronic, or that it still uses line judges, with the source for each
Grand Slam	Fully electronic since	System named	Confidence	Note
Australian Open	2021'There are just no mistakes happening': Hawk-Eye Live gains more support at Australian OpenPublished 13 February 2021	Hawk-Eye Live	confirmed	First Grand Slam with no line judges on any court. Introduced as a COVID-19 measure. Players could still ask to see the replay.
Roland Garros	Not yet. Line judges in 2026French Open chief Mauresmo backs human judgment after Ruud line-call controversy (Associated Press)Published 1 June 2026	None named	confirmed	Line judges kept for 2026. Tournament cited clay reliability concerns.
Wimbledon	2025Pavlyuchenkova back in Wimbledon quarterfinals after 9 yearsPublished 6 July 2025	Hawk-Eye Live	confirmed	First Wimbledon without line judges. ELC on all match and qualifying courts. System was switched off in error for one game on Centre Court.
US Open	20211 to go: Djokovic into US Open final, nears year Grand Slam (Associated Press)Published 11 September 2021	Hawk-Eye Live	confirmed	First US Open with no line judges on any court. AP said rulings came from electronic calling and could not be disputed. See the README on 2021 versus 2022.

Sources disagree on the first US Open with no line judges. An NPR report from September 2022 reads as if 2022 was the first fully electronic year. We use 2021. The USTA announced in May 2021 that Hawk-Eye Live would cover every court that year. ESPN reported in September 2022 that the US Open extended the system to Ashe and Armstrong in 2021. AP reported from the 2021 semi-finals that there were no line judges to argue with. An AP report from October 2024 also says the US Open has had no line judges since 2021.

What does the dataset cover?

278 rows across 38 events, from 2017 to 2026. The rows cite 75 distinct source pages. It includes these events.

The four Grand Slams, one combined row per event.
The ATP Finals and the Next Gen ATP Finals.
The nine ATP Masters 1000 events.
WTA 1000 events, and the Premier Mandatory and Premier 5 events that came before them.
The WTA Finals.
The ATP Cup, United Cup, Davis Cup Finals and Billie Jean King Cup Finals.
ATP 500 events in 2025 and 2026 only. The ATP's own tour-wide statements cover those two seasons.

Events that were not held have no row. That covers Wimbledon 2020, the other events cancelled in 2020, the events in China from 2020 to 2022, and Wuhan in 2023. Events still to be played after 22 October 2026 are also left out.

How were lines called?

The line_calling column takes one of 5 values. The counts are from the current file.

Rows by line_calling value
Value	What it means	Rows
`line_judges`	Human line judges and no electronic challenge. Clay events used this before electronic calling arrived.	28
`challenge_system`	Human line judges, with an electronic review players could request on some or all courts.	64
`elc_some_courts`	Live electronic calling on some courts and line judges on others.	1
`elc_all_courts`	Live electronic calling on every court, with no line judges.	107
`unknown`	We found no source we trust for that row.	78

What do the confidence levels mean?

Each row says how sure the dataset is about it.

Rows by confidence level
Value	What it means	Rows
`confirmed`	A source published during or after the event says it for that event and that season.	41
`inferred`	The source is a tour-wide rule or an announcement made before the event. Or it describes an adjacent season or a range of seasons. The note says which.	159
`unknown`	No supporting source. These rows always have line_calling set to unknown. Some still link a page that gives context, such as the system a tournament named.	78

Limits worth knowing, from the dataset README.

Many rows are inferred from tour-wide rules. A rule says what events had to do. It does not prove what happened at each one.
Court-by-court detail is rarely published. elc_all_courts rows that rest on a tour rule have not been checked court by court.
ATP 500 and WTA 500 events before 2025 are not included. WTA 500 events in 2026 are not included either.
Source pages can move or disappear. We do not archive copies.

How do I download the data?

line_calling.csv: UTF-8 CSV with a header row and 12 columns.
line_calling.csv-metadata.json: the same columns in the W3C CSV on the Web format.
The project on GitLab: the README, the validator and the full change history.

The columns are event, tour, season, surface, line_calling, elc_system, challenge_review, notes, source_url, source_title, source_date and confidence.

How do I cite it?

Live Tennis API (2026). Electronic line calling in professional tennis, by tournament and season (Version 1.0.0) [Data set]. https://gitlab.com/livetennisapi/tennis-line-calling

@misc{livetennisapi_line_calling_2026,
  author       = {{Live Tennis API}},
  title        = {Electronic line calling in professional tennis, by tournament and season},
  year         = {2026},
  version      = {1.0.0},
  howpublished = {\url{https://gitlab.com/livetennisapi/tennis-line-calling}},
  note         = {Data set, CC BY 4.0}
}

The project's CITATION.cff file holds the same details.

What licence is it under?

CC BY 4.0. You can share and adapt the data, including for commercial use, as long as you credit Live Tennis API. Read the licence summary.

How do I report a wrong row?

Open an issue on GitLab. Please include the event, the season and a link to a source that supports the change. Each change to the data gets a new version number.

Building something with tennis data? See the historical tennis data API.

The figures on this page are from dataset version 1.0.0, released 22 October 2026. The download links always serve the latest version.