Electronic line calling in tennis: charts to embed
Three charts show how professional tennis moved from line judges to electronic line calling between 2017 and 2026. They are drawn from our free line-calling dataset. Paste the code under a chart into your page and the chart shows there, with its source. They are free to use under CC BY 4.0.
How did the ATP and WTA tours call lines each season?
How the ATP and WTA tours called lines, 2017 to 2026
In 2026, 22 of 22 ATP events and 10 of 10 WTA events in the dataset called every line electronically. In 2017 it was 1 of 11 and 0 of 10.
Electronic on every court
Line judges and challenges
Line judges only
No trusted source
Columns count the events in the dataset for each tour and season. 60 of the 220 have no trusted source. The dataset covers ATP 500 events in 2025 and 2026 only.
Show the numbers as a table
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.
<iframe src="https://livetennisapi.com/widgets/line-calling/tours?theme=light" title="How the ATP and WTA tours called lines, 2017 to 2026" height="750" style="border:0;width:100%" loading="lazy"></iframe>
<p>Chart and data by <a href="https://livetennisapi.com/data/tennis-line-calling">Live Tennis API</a></p>
How the four Grand Slams called lines, 2017 to 2026
In 2026, 3 of the 4 Grand Slams called every line electronically.
Electronic on every court
Electronic on some courts
Line judges and challenges
Line judges only
No row
Each cell is one tournament in one season. A dash marks a season with no row. Events that were not held have no row.
Show the numbers as a table
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.
<iframe src="https://livetennisapi.com/widgets/line-calling/grand-slams?theme=light" title="How the four Grand Slams called lines, 2017 to 2026" height="620" style="border:0;width:100%" loading="lazy"></iframe>
<p>Chart and data by <a href="https://livetennisapi.com/data/tennis-line-calling">Live Tennis API</a></p>
How many rows record electronic line calling each season?
Every row of the line-calling dataset by season, 2017 to 2026
In 2026, 36 of 38 rows record electronic calling on every court. In 2017 it was 1 of 25.
Electronic on every court
Electronic on some courts
Line judges and challenges
Line judges only
No trusted source
Each row is one event in one season for one tour. An event with an ATP and a WTA draw has a row for each, and a Grand Slam has one combined row. 78 of the 278 rows have no trusted source and are drawn as their own group.
Show the numbers as a table
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.
<iframe src="https://livetennisapi.com/widgets/line-calling/seasons?theme=light" title="Every row of the line-calling dataset by season, 2017 to 2026" height="640" style="border:0;width:100%" loading="lazy"></iframe>
<p>Chart and data by <a href="https://livetennisapi.com/data/tennis-line-calling">Live Tennis API</a></p>
Copy the code under the chart and paste it into your page as HTML. The chart fills the width it is given, down to a phone screen. It runs no script, sets no cookies and loads nothing from another site.
For a dark box, change theme=light to theme=dark in the code. If the box cuts the chart off, raise the height number.
How do I credit the charts?
The charts and the data are under CC BY 4.0. You can use them, including for commercial work, as long as you credit Live Tennis API. Read the licence summary.
Each embedded chart carries its own source line with a link, so the code above already gives the credit. Please keep the line under the box too.
If you use the SVG file or redraw a chart, put this credit beside it.
<p>Chart: <a href="https://livetennisapi.com/data/tennis-line-calling">Live Tennis API line-calling dataset</a>, <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a></p>
In print, or where a link cannot go, use this line. Data: Live Tennis API line-calling dataset (livetennisapi.com/data/tennis-line-calling), CC BY 4.0.
What happens to rows with no source?
78 of the 278 rows have no source we trust. The charts draw them as their own outlined group. They are never left out and never counted as one of the known methods. The table under each chart gives the same numbers.
Found a wrong row? Open an issue on GitHub with a source, and the charts change when the dataset does.
These charts use dataset version 1.0.1, released 13 November 2026. The data runs to 22 October 2026.
Live Tennis API
