Data quality updated: 2026-09-15 09:13 UTC
ATP Data Quality & Coverage
Coverage, update times, sources, and known gaps in the ATP statistics.
How to read this page
Check which ATP matches and seasons are covered, when the data was updated, and where gaps remain. The source notes explain how records are combined and why a statistic may differ from another reference.
Counts cover recorded completed main-tour and Olympic singles matches. They describe the size of the archive, not the percentage of all historical matches captured.
Coverage Overview
Data Sources
| Source | Period | Matches | Share |
|---|---|---|---|
| Jeff Sackmann / Tennis Abstract (opens in new tab) | 1968–2024 | 205,652 | 95.2% |
| BALLDONTLIE API | 2025–present | 9,557 | 4.4% |
| International Tennis Federation (opens in new tab) | Official Olympic singles draws, 1988–present | 638 | 0.3% |
| Manual corrections & other reconciled sources | Rows retained after source review | 146 | 0.1% |
Source Priority Rules
Which source is used when records overlap or disagree.
Matches
ATP match pages use Jeff Sackmann records before 2025 and BALLDONTLIE records from 2025 onward. That split keeps historical records stable while allowing current-season results to publish quickly.
Rankings
ATP rankings follow the same source split: Sackmann before 2025, BALLDONTLIE from 2025 onward.
Categories
Historical categories use documented modern equivalents for comparisons. A tournament's current category is not automatically applied to every past edition.
Olympic singles
Official ITF draws supply the complete medal-era singles archive from Seoul 1988 through the latest completed Games. Gold counts as one title; event-time NOCs remain distinct from current nationality. Walkovers count in TennisDB W-L records and streaks but do not affect Elo or played-only stats.
Coverage by Era
ATP main-tour singles match records by decade. Coverage improves in more recent decades as data sources become more comprehensive.
| Decade | Matches |
|---|---|
| 1960s | 5,947 |
| 1970s | 35,741 |
| 1980s | 33,387 |
| 1990s | 33,686 |
| 2000s | 37,611 |
| 2010s | 44,113 |
| 2020s | 25,508 |
Advanced Metric Coverage
Advanced metrics stay blank when the required evidence is unavailable. Leaderboards apply additional minimum-sample and point-stat coverage rules.
| Metric family | Available evidence |
|---|---|
| Elo, surface lift, and schedule effect | All eras with eligible match results and opponent identities. |
| Performance+, Set Win %, Set Margin, deciding sets, and tiebreaks | Matches with parseable completed scores; older seasons may have gaps. |
| Serve+, Return+, Point Dominance, and Total Points Won % | Matches with usable serve and return statistics. Values are best-effort, match-weighted, and shrunk toward the tour-season baseline because historical sources do not always expose point denominators. |
Data Freshness
When site data was last updated.
| Event | Time (UTC) | Status |
|---|---|---|
| Last data ingest | Sep 15, 2026 9:40 UTC | success |
| Last serving layer refresh | Sep 15, 2026 9:13 UTC | success |
Known Limitations
Accepted data limitations that we are aware of and working to improve over time.
Historical match coverage varies by era
TennisDB's open historical ATP record is broad, but it is not an official completeness census. Coverage varies by event, era, round, and available source, so older win-loss records and title counts can be lower than ATP official figures. The decade counts above describe what TennisDB currently holds; they are not completeness percentages.
Historical tournament categories use modern equivalents
TennisDB groups documented historical predecessor editions under modern Masters 1000, ATP 500, and ATP 250 categories for cross-era comparison. Historical labels remain separate in the audit record, and editions without a supported mapping retain their recorded category.
Detailed performance-stat coverage is partial
Serve and return metrics are calculated only when a match has the core detailed-stat inputs needed by every displayed percentage. Player, season, and head-to-head pages expose detailed-stat matches over total main-draw matches so partial samples are visible rather than presented as complete.
"Turned pro" year is approximate for historical players
For players active before ~2000, the displayed turned-pro year reflects the first season with ATP main-tour match data, which may differ from official records by 1-3 years.
Prize money is source-dependent
Career prize money is reconciled from official tour PDFs, Wikidata, and BALLDONTLIE where available. Most prominent historical players should have values, but lower-ranked historical players may still have gaps.
Early ATP ranking history is limited
The ATP computer ranking system began in August 1973, so no ATP rankings exist for earlier seasons. The earliest available snapshots are also sparser and less regular than modern weekly histories.
Recently retired players on active leaderboards
Players who have retired but still hold an ATP ranking (within the 52-week rolling window) may appear on active leaderboards until their ranking points expire naturally.
If you spot something that looks wrong, please let us know.