The home team wins 55.7%, and about a fifth of that comes from visitors who can't fill every line
Home teams do win more: the home team won 55.7% of 15,721 decided team matches in Marin-area and San Francisco USTA NorCal adult league.
Home wins in every group of matches
A line one side can't fill is awarded to the other side and counts like a played one. The side that comes up short is usually the visitor, so part of this edge is lineups rather than tennis.
How much of the edge is lineups?
About a fifth of it. In 1,936 of the 15,721 matches, a side named no players for at least one line, and the home side won 65.5% of those 2,353 empty lines. Without those matches the home rate falls 1.1 points, to 54.6%, which is about a fifth of its edge over a coin flip.
Is it just that better teams play at home more?
No. The test takes only pairs of teams who played each other once at each venue in a season and split the two matches. They fielded every line both times, so team strength is the same on both sides. In 530 of those 904 pairs each team won its home match, and in the other 374 each won away.
Those 530 pairs are 58.6% of the 904, which runs high because a split leaves only close matches, where a venue matters most. The figure to quote is still 55.7%.
Season by season
The home team came out ahead in every season from 2022 to 2026, and the edge barely moved.
| Season | Home team won |
|---|---|
| 2022 | 56.1% |
| 2023 | 55.7% |
| 2024 | 55.4% |
| 2025 | 55.4% |
| 2026 | 56.0% |
An edge this steady fits something about playing at home, such as a familiar court or the visitors' drive after work, but the scorecards the Desk reads record neither.
With both lineups full, the home team won 54.6% of 13,785 matches.
All Tennis Desk Research·Browse every league the Desk holds, by year and area
How this was measured
Scope. USTA NorCal adult league scorecards from Marin County and San Francisco, for the seasons 2022 to 2026. The figures cover those two areas, not NorCal or the country. 15,721 team matches had a decided result, and the 251 that ended level are left out because a tie has no winner.
What "home" means here. The home team is the side the scorecard lists at home. USTA NorCal league matches are played at the home team's facility, but nothing in this data records a venue. So what is measured is the label, and any explanation involving actual courts is an inference rather than a measurement.
What "a line went unfielded" means. A line on the scorecard where one side named no players at all, which is the clearest sign of a defaulted line that the scorecards carry. It says nothing about any one team, and no team or player is named anywhere on this page.
Measured. Every figure above was checked against the live database on October 6.
Method. Every figure above was produced by the SQL recorded in docs/research/records/home-advantage.json, re-run before this page was built. The record also lists each other explanation that was tested, and the one that could not be: whether a match was really played on the home team's courts. Reproduce with npx tsx scripts/measure-research-record.ts.