Tennis Statistics Glossary

Definitions for every stat, metric, and abbreviation used on TennisDB.

Rankings & Ratings

Ranking: A player's current position in the official ATP singles rankings, determined by ranking points accumulated over a rolling 52-week period. Lower is better — #1 is the top-ranked player.
Season Ranking: For the current season, this is the latest ranking. For past seasons, this is the year-end ranking. Lower is better — #1 is the top-ranked player.
Peak Ranking: The highest (lowest-numbered) ranking position a player has ever achieved in their career. Also called Career High.
Ranking Points: Official ranking points from the selected ranking snapshot. Official tour points are awarded based on tournament results over the previous 52 weeks. Grand Slams award the most points, followed by Masters 1000 events, 500s, and 250s. Points from the same tournament the prior year usually drop off as new results replace them.
Ranking Snapshot: A dated official ranking list used as the source for current, weekly, and year-end ranking views. Snapshot dates matter because rankings can change every week during the season.
Season Age: A player's age on July 1 of the calendar season. TennisDB uses this fixed midseason date when labeling and comparing age-based seasons; it is different from a player's exact age on a particular match or ranking date.
Weekly Rank Movement (Wk +/−): Ranking change since the previous ranking snapshot. A positive value means the player moved closer to No. 1.
Year-to-Date Rank Change (YTD Δ): Ranking change since the start of the season. A positive value means the player improved during the season.
Weeks at No. 1: Weeks spent at No. 1 in the official rankings. This is based on official ranking history snapshots and is most useful for comparing sustained time at the top.
Elo Rating: Elo is a form-based rating that updates after each match. Beating stronger opponents earns more points; losing to weaker opponents costs more. Unlike official rankings, Elo gives credit based on who you beat, not which round or tournament you played in. TennisDB maintains separate overall and surface Elo ratings.
Season Elo: For the current season, this is the latest TennisDB Elo rating. For past seasons, this is year-end Elo.
Peak Elo: The highest Elo rating a player has reached in TennisDB's ratings. It is useful for comparing how strong players looked at their best, especially when official rankings or ranking points are not directly comparable across eras.
Elo Percentile (%ile): Percentile rank by Elo rating. 99 means higher than 99% of comparable players. Shown overall and per surface when the player has enough matches on that surface.

Match Results

W-L (Win-Loss Record): Wins and losses in completed main-draw singles matches. Shown as career totals, per-season, per-surface, and by opponent ranking tier. Qualifying-round matches are tracked separately from main-draw results.
Win %: Wins divided by total completed main-draw matches. Calculated as wins ÷ (wins + losses) × 100.
Titles: Singles tournament titles in TennisDB's title data. Counted overall and broken down by category: Grand Slam, Masters 1000, ATP 500, ATP 250, and ATP Finals.
Finals Win %: Singles titles divided by singles finals reached. This measures conversion in title matches rather than simply how often a player reached finals.
Grand Slam Finals Win %: Grand Slam singles titles divided by Grand Slam singles finals reached.
Masters 1000 Finals Win %: Masters 1000 or WTA 1000 singles titles divided by finals reached at that level.
Win Streak: Longest consecutive winning streak in completed singles matches, excluding walkovers.
YTD W-L: Year-to-date wins and losses — the player's match record in the current calendar year.
Prize Money: Career prize money when available from source data. TennisDB shows this in US dollars where available.

Serve Statistics

Aces: Serves that land in and are not touched by the returner. It wins the point outright for the server.
Aces per Match (Aces/M): Aces per match with serve stats available. Higher values usually indicate a more dominant serve.
Double Faults (DFs): Service points lost by missing both first and second serve.
DFs per Match: Double faults per match with serve stats available.
First Serve % (1st Sv%): Percentage of service points where the first serve landed in. Higher percentages mean less reliance on the weaker second serve.
First Serve Points Won % (1st Sv Pts%): Percentage of points won after making a first serve. Top servers usually separate themselves here.
Second Serve Points Won % (2nd Sv Pts%): Percentage of points won after missing the first serve and making a second serve. This is usually lower than first-serve points won because the second serve is generally slower and more conservative.
Break Points Saved % (BP Saved%): Percentage of break points won by the server. A break point is when the returner needs one more point to win the server's game.
Service Points Won % (Svc Pts%): Percentage of all points won while serving. It combines first-serve and second-serve performance.
Serve Rating: Composite serving rating derived from available serve stats. It combines several available serve stats into one serving-strength signal.

Return Statistics

Return Points Won % (Ret Pts%): Percentage of all points won while returning. Since the server has a natural advantage, small differences can matter a lot.
Break Points Converted % (BP Conv%): Percentage of break-point chances won by the returner. A break point is when the returner needs one point to win the server's service game.
Return Rating: Composite returning rating derived from available return stats. It combines several available return stats into one return-strength signal.
Total Points Won %: Percentage of all completed points won. In a competitive match, this number is often close to 50% for both players.

Advanced Metrics

Set Win %: Sets won divided by total completed sets in eligible scored matches.
Set Margin: Average per-set game margin from the player's perspective. Positive values mean winning sets by more games on average. Each set's game delta, such as 6-3 = +3 or 7-5 = +2, is averaged across completed sets. Values near zero indicate tighter matches. Retirements, walkovers, and matches with too little completed set data are excluded.
SoS % (Strength of Schedule): Strength of Schedule percentile based on opponent quality. Higher means the player faced tougher opponents. A SoS of 90% means the player faced tougher opponents than 90% of peers.
vs Expected: Wins above or below Elo prediction over the player's last 20 matches. Positive means outperforming expectations.
Deep Run %: Share of tournaments where the player reached the quarterfinals or better. It measures consistency at going deep in draws rather than simply collecting wins.
Deciding Set Win % (Dec. Set W%): Win percentage in matches that reached a deciding set. The deciding set is the 3rd set in best-of-3 or the 5th set in best-of-5.
Tiebreak Win %: Tiebreaks won divided by total tiebreaks played. Tiebreaks are usually played when a set reaches 6-6.
Form Score: A recency-weighted performance metric used to identify players who are currently on a hot or cold streak. Factors in recent match results, opponent quality, and how recent each result is.
Record vs Top 10 / Top 20 / Top 50 / Top 100: Wins against opponents ranked in the Top 10 at the time of the match. The same logic applies to Top 20, Top 50, and Top 100 splits. These records show how a player performs against different tiers of competition.
Sample: Matches with the required stat data available. Not all historical matches have detailed serve and return data, so sample size helps show how stable the averages are.

Surfaces

Hard Court: An acrylic or concrete surface. The most common surface on tour, used at the Australian Open, US Open, and most Masters 1000 events. Produces a medium-paced, relatively consistent bounce.
Clay Court: A surface made of crushed brick or shale. Used at the French Open (Roland Garros) and several European tournaments. Produces a high, slow bounce that favors baseline players and long rallies.
Grass Court: A natural grass surface. Used at Wimbledon, Queen's Club, and Halle. Produces a low, fast, sometimes unpredictable bounce that favors serve-and-volley play and aggressive styles.
Carpet: A removable synthetic surface used historically at indoor events. No longer part of the professional tour but appears in historical records. Generally fast-paced, similar to indoor hard courts.

Tournament Categories

Grand Slam: The four most prestigious tournaments in tennis: Australian Open, French Open (Roland Garros), Wimbledon, and the US Open. Feature 128-player draws, best-of-5-set matches (men's singles), and award the most ranking points (2,000 for the champion).
Masters 1000: The top tier of ATP tour events below Grand Slams, awarding 1,000 ranking points to the winner. Nine events held annually, including Indian Wells, Miami, Monte Carlo, Madrid, Rome, Canada, Cincinnati, Shanghai, and Paris.
ATP 500: Mid-tier ATP tour events awarding 500 ranking points to the winner. Includes events like Barcelona, Queen's Club, Halle, and Basel.
ATP 250: The most common tier of ATP tour event, awarding 250 ranking points to the winner. Features 32-player draws at venues worldwide.
ATP Finals: The season-ending championship featuring the top 8 ranked singles players. Uses a round-robin format followed by knockout semifinals and final. Awards up to 1,500 ranking points.
Qualifying (Q): A preliminary competition held before the main draw of a tournament. Players outside the direct-acceptance cutoff compete for a limited number of spots in the main draw. Qualifying results are tracked separately from main-draw records on TennisDB.

Rounds

F (Final): The championship match of a tournament. The winner claims the title.
SF (Semifinal): The round before the final. Winners advance to the final; losers finish as semifinalists.
QF (Quarterfinal): The round of the last 8 players. Winners advance to the semifinals.
R16 (Round of 16): The round of the last 16 players. Sometimes called the fourth round at Grand Slams.
R32 (Round of 32): The round of the last 32 players. The third round at Grand Slams.
R64 (Round of 64): The round of the last 64 players. The second round at Grand Slams.
R128 (Round of 128): The first round at Grand Slams, which feature 128-player draws.
RR (Round Robin): A group-stage format where each player plays every other player in their group. Used at the ATP Finals.
Q1, Q2, Q3 (Qualifying Rounds): The first, second, and third rounds of qualifying. Players must win all qualifying rounds to earn a main-draw spot.
BR (Bronze Medal Match): A third-place match, used at the Olympic Games.

Match Formats & Scoring

Best of 3 Sets: The standard match format for most tour-level events. The first player to win 2 sets wins the match.
Best of 5 Sets: The match format used at Grand Slam tournaments (men's singles) and formerly at the ATP Finals. The first player to win 3 sets wins the match.
Tiebreak: A special game played when a set reaches 6-6. Players alternate serves in a first-to-7-points (win by 2) format. At Grand Slams, final-set tiebreak rules vary by event: some use a first-to-10-point tiebreak at 6-6.
3-Set Match Win %: Win percentage in completed best-of-three-set singles matches. It is a useful signal for tight best-of-3 matches.
5-Set Match Win %: Win percentage in completed best-of-five-set singles matches. It is most relevant for men's Grand Slam matches.
Walkover (W/O): When a player wins a match because the opponent withdraws before the match begins. Does not count as a win in W-L records.
Retirement (Ret.): When a player stops playing during a match due to injury or other reasons. The opponent is credited with the win.

Data & Site Terms

Serving Layer: The pre-computed database tables TennisDB reads when rendering public pages. Expensive reconciliation, aggregation, and ranking calculations run during background refresh jobs instead of during page requests.
Source Priority: The rule TennisDB uses to choose which upstream source should publish a record when more than one source has similar data. ATP uses Sackmann before 2025 and BallDontLie from 2025 onward. WTA matches can use BallDontLie as historical gap-fill, while WTA rankings use Sackmann before 2025 and BallDontLie from 2025 onward.
Deduplication: The refresh-time process that removes equivalent match rows from multiple sources using score, tournament, round, date, and player-identity signals.
Active Player: A player who appears active in recent ranking or match data. This is a site classification based on available data signals, not an official retirement declaration.
Leaderboard: Single Season: Ranks the best individual player-seasons for the selected statistic across the chosen era.
Leaderboard: Career: Ranks career totals or career rates across the chosen era.
Leaderboard: Active: Uses the same career measure but includes only players TennisDB currently classifies as active.
Leaderboard: Year-by-Year: Shows the leading player or player-season separately for each season.
Leaderboard: By Current Rank: Lists currently ranked players in official ranking order and shows their full-history career statistic.
Markdown Mirror: A compact plain-text version of a public page, available by appending .md to supported canonical URLs. These mirrors begin with a source URL and are intended for citation-friendly AI and search retrieval.
Updated Timestamp: The best available freshness signal for a page. Depending on the page type, it can come from a live score update, ranking snapshot, match refresh, news publish time, or sitewide serving refresh.