tennis
Arthur Fils and Cori Gauff: A Surface Elo Deep Dive
Most Elo coverage ranks players against the rest of the field. This piece looks inside two players’ own numbers instead, comparing each one’s overall rating to their three surface ratings and to what they have actually done in their most recent logged matches. Two names make the case well right now: Arthur Fils, ATP’s No. 4 overall by our model, and Cori Gauff, WTA’s No. 1. Both sit inside their tour’s top 10, and both show a pattern worth a closer look once you stop reading “No. 1” or “No. 4” as a single number and start reading it as three different surface stories.
All ratings below come from our surface-specific Elo model, trained on data through October 4, 2026 (03:09 UTC), across 34,170 processed matches. Ratings are recalculated weekly as new results come in, not on a fixed historical window, so the exact figures here will have moved on by the time you read this. Player-level detail, including logged match counts and recent-match records, comes from each player’s own page, last updated the same day.
Arthur Fils: ATP’s No. 4 overall, and the tightest surface spread near the top
Arthur Fils’s overall Elo rating is 1922, fourth-highest on the ATP tour behind Jannik Sinner, Carlos Alcaraz and Alexander Zverev. That overall figure is built from his full logged match history, 82 matches, not a simple average of his three surface ratings.
| Surface | Elo Rating | Tour Rank (surface) | Logged Matches | Gap to Overall |
|---|---|---|---|---|
| Overall | 1922 | 4th | 82 | n/a |
| Hard | 1853 | 3rd | 47 | 69 |
| Clay | 1834 | 4th | 25 | 88 |
| Grass | 1808 | 7th | 2 | 114 |
Every one of his three surface gaps is under 115 points, and his widest gap, grass at 114 points, is also built from his thinnest sample by far: just 2 logged matches. His hard-court number is both his closest to his overall rating in absolute terms (69 points) and his best surface rank (3rd on the ATP hard list), while carrying his largest surface sample of the three (47 matches). That is a notably tighter, more even spread across surfaces than some other players near the top of the same list, where one surface can sit well over 100 points from the overall figure while another sits much closer.
Fils’s recent record
His 10 most recent logged matches, all played on hard courts:
- Wins: Frances Tiafoe (Oct. 2 and Aug. 23), Luca Van Assche (Sept. 30), Kamil Majchrzak (Sept. 29), Martin Damm (Sept. 28), Flavio Cobolli (Aug. 22), Thiago Agustin Tirante (Aug. 20), Alex De Minaur (Aug. 19), Jiri Lehecka (Aug. 17)
- Losses: Stefanos Tsitsipas (Aug. 31)
That is 9 wins and 1 loss across his last 10 logged matches, all on the surface where his rating already sits closest to his overall level. A short win-loss stretch like this does not move an Elo rating built on 47 hard-court results very far on its own; it is a separate, recent data point, not a recalculation of the rating itself.
Cori Gauff: WTA’s No. 1 overall, but outside the grass top 20
Cori Gauff’s overall Elo rating is 2028, the highest on the WTA tour, ahead of Aryna Sabalenka and Elena Rybakina. That figure is built from 114 logged matches, her largest sample of any number on this page.
| Surface | Elo Rating | Tour Rank (surface) | Logged Matches | Gap to Overall |
|---|---|---|---|---|
| Overall | 2028 | 1st | 114 | n/a |
| Hard | 1960 | 3rd | 71 | 68 |
| Clay | 1894 | 4th | 27 | 134 |
| Grass | 1702 | Outside top 20 | 11 | 326 |
Her hard-court gap, 68 points on 71 matches, is the closest of her three surfaces to her overall figure, and nearly identical in size to Fils’s own hard-court gap. Her clay gap is wider, 134 points on 27 matches. Her grass number is the outlier: 1702, a 326-point gap to her overall rating, on only 11 logged matches. That rating does not clear our WTA grass leaderboard at all; the 20th and lowest rating published on that list is 1744, so her 1702 falls below the cutoff rather than simply being thin on grass-specific matches. Being the tour’s No. 1 overall by this model does not guarantee a published ranking on every individual surface.
Gauff’s recent record
Her 10 most recent logged matches, also all on hard courts:
- Wins: Maria Camila Osorio Serrano (Oct. 3), Mirra Andreeva (Sept. 9), Iva Jovic (Sept. 7), Cristina Bucsa (Sept. 5), Paula Badosa Gibert (Sept. 3), Zeynep Sonmez (Sept. 1), Jessica Pegula (Aug. 23), Sara Bejlek (Aug. 22), Marta Kostyuk (Aug. 21)
- Losses: Elena Rybakina (Sept. 10)
That is also 9 wins and 1 loss across her last 10 logged matches, an identical record to Fils’s over the same stretch length, on the same surface type.
What both players share, and where they differ
Fils and Gauff land on the same basic shape: an overall rating built from their full match log that sits above every one of their individual surface numbers, and a hard-court gap, the surface both are currently playing on, that is the smallest of their three. Both are also 9-1 in their last 10 logged matches, all on hard courts. Neither of those similarities should be read as more than a coincidence of timing; the two tours, the two rating scales and the two player profiles are otherwise unrelated.
Where they differ is how even the rest of the spread is. Fils’s widest gap is 114 points, on grass, a surface where he has barely played (2 matches) in our log. Gauff’s widest gap is 326 points, nearly three times larger, also on grass, but on a larger sample of 11 matches, and large enough to put her outside the published top 20 on that surface entirely despite her overall rating being the highest on the WTA tour. A single overall number, No. 4 or No. 1, describes very different underlying surface pictures for these two players.
How this compares to the very top of each tour
The pattern does not generalize to every player near the top of either list. Jannik Sinner carries the highest overall rating in the men’s game, 2135, but his hard-court number, 1948, is 187 points under that, his widest surface gap and larger than Fils’s widest gap of 114 points, though smaller than Gauff’s 326-point grass outlier. Carlos Alcaraz sits closer to Fils’s shape: a 76-point hard-court gap, his smallest of the three, against 84 on clay and 95 on grass. On the WTA side, Aryna Sabalenka is the one real exception to “overall sits above every surface”: her hard-court rating, 2029, is actually 12 points above her overall figure of 2017, with clay and grass both 140 points under. Elena Rybakina’s hard-court rating, 2008, sits just 4 points under her 2012 overall figure, the tightest hard-to-overall gap of any player discussed here. There is no single relationship between “overall rating” and “current-surface rating” that holds across the whole field; each player’s own split is its own case.
Turning any of these gaps into a probability
None of the numbers above say anything about a specific upcoming opponent. A rating gap only becomes useful once it is compared against another player’s rating on the same surface. For an actual head-to-head comparison, the Elo probability calculator converts two ratings directly into a win probability rather than asking you to eyeball the difference.
What this data doesn’t show
Neither player’s surface split explains why the gap exists. A change in scheduling that puts more matches on one surface than another, simple variance in a growing match database, or factors the model never sees at all, injuries, coaching changes, conditions on a given day, could all produce a similar-looking number. The model also does not know about anything outside the match results it processes.
Sample size is the other standing caveat, and it cuts in different directions for these two players. Fils’s grass rating, on just 2 logged matches, is the thinnest number on this page by a wide margin and should be treated as closer to a placeholder than a measurement. Gauff’s grass rating, on 11 matches, is a steadier number but still her smallest surface sample, and it is the sample that produced her widest gap. Every other rating discussed here is built on at least 25 logged matches.
Where to check the live numbers
The figures above are a snapshot from our October 4, 2026 training run. Because every rating here is recalculated weekly as the match database grows, check the full Elo leaderboard, or Fils’s and Gauff’s own player pages, for current numbers. Neither this article nor any page it links to is a prediction for a specific upcoming match; it is a form reference, current as of the training date stated above.
Frequently asked questions
- Why is Arthur Fils rated closest to his overall level on hard courts?
- His hard-court Elo is 1853, built from 47 logged matches, versus an overall rating of 1922 built from 82 matches. That is a 69-point gap, the smallest of his three surfaces. His clay rating (1834, on 25 matches) is 88 points under overall, and his grass rating (1808, on just 2 logged matches) is 114 points under, the widest gap of the three but also by far the thinnest sample.
- Why doesn't Cori Gauff appear on the WTA grass Elo top 20 despite being No. 1 overall?
- Her grass rating is 1702, built from 11 logged matches. The 20th-ranked rating on our WTA grass top 20 list is 1744, so her number falls below that cutoff and she does not appear on the published list at all. That is not because 11 matches is an unusually thin sample for grass specifically; the leaderboard simply publishes only the top 20 ratings on each surface, and hers does not clear that bar.
- What do Fils's and Gauff's most recent matches show?
- Both are 9-1 across their last 10 logged matches, and in both cases all 10 were played on hard courts, matching the current point in the calendar. Fils's only loss in that stretch was to Stefanos Tsitsipas; Gauff's only loss was to Elena Rybakina.
- Does ranking No. 1 or No. 4 overall by Elo mean that player is favored in their next match?
- No. Elo converts a rating gap between two specific players into a win probability for that matchup; it says nothing on its own about any single opponent. Overall rank also blends all three surfaces, so a player's edge can look very different once you isolate the surface a given match is actually played on. Our probability calculator converts a specific rating gap into a number rather than asking you to eyeball it.
- Where can I check the current Elo numbers for these two players?
- Their individual player pages carry the live figures, and the full Elo leaderboard shows every published rating across both tours and all three surfaces. Ratings are recalculated weekly from our growing match database, so the exact numbers here will drift over time; that is the model incorporating new results, not an error in this article.