US Open · Q3 · Hard · 22 Aug 2025
Aoi Ito v Janice Tjen
29–57 in points · Janice Tjen won
Why it went the way it did
Janice Tjen won 13.8 more points than Aoi Ito relative to what the serve alone predicted. Aoi Ito's biggest leaks: backhand execution −4.0, slice shot selection −3.6, net execution −2.1.
Each shot moves its hitter's chance of winning the point. Those moves are split into direction choice, shot selection and execution, and summed here. Read both columns together: one player's gain is the other's loss.
| Shot | Aoi Ito | Janice Tjen | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.1 | ±0.0 | ±0.0 | −0.1 | +0.3 | ±0.0 | +2.5 | +2.8 |
| Serve 2nd | −0.1 | ±0.0 | ±0.0 | −0.1 | ±0.0 | ±0.0 | +0.5 | +0.5 |
| Return | −0.1 | −1.5 | −0.8 | −2.4 | +0.1 | −1.0 | +2.6 | +1.6 |
| Forehand | +0.2 | +0.7 | −1.6 | −0.7 | −0.4 | +1.9 | −1.3 | +0.3 |
| Backhand | +0.5 | +1.2 | −4.0 | −2.3 | ±0.0 | +0.2 | −0.3 | ±0.0 |
| Slice | −0.3 | −3.6 | +0.1 | −3.7 | +0.5 | −4.2 | +0.9 | −2.9 |
| Net | −0.1 | −0.2 | −2.1 | −2.4 | ±0.0 | +0.3 | −0.5 | −0.2 |
| Touch | ±0.0 | ±0.0 | ±0.0 | ±0.0 | ±0.0 | −0.1 | ±0.0 | −0.1 |
| All shots | +0.1 | −3.4 | −8.4 | −11.7 | +0.5 | −2.9 | +4.6 | +2.2 |
Set by set
| Set | Aoi Ito | Janice Tjen | Net, Aoi | |
|---|---|---|---|---|
| 1 | −7.6 | +1.3 | −8.9 | |
| 2 | −4.1 | +0.9 | −5.0 |
Adaptation
First-serve direction mix set by set, with the share of points each direction won. The scores measure whether the server moved toward the directions that had been winning earlier in this match, set to set and every two to three service games, in points per 100 first serves. Read them as a habit, not a gain: across the tour, a direction's edge in early sets barely predicts the later ones. Whether the returner responded can't be told apart from noise within one match.
Aoi Ito serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 26% 40% | 21% 25% | 53% 30% |
| 2 | 52% 67% | 26% 17% | 22% 40% |
Within sets +1.88 per 100 first serves, every two to three service games
Janice Tjen serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 86% 83% | – | 14% 100% |
| 2 | 50% 67% | 7% 0% | 43% 77% |
Within sets +0.59 per 100 first serves, every two to three service games
Counterfactual: the best direction every time
If each shot had gone in the direction that is usually worth most for that stroke and position, this is how many more points each player would expect to win. It's an upper bound: the best direction isn't always on, and the chart can't see the ball's pace or position.
Aoi Ito
4.2 points left on the table across 157 shots 2.68 per 100 shots
- Rally, shots 5–8: slice to your backhand side hit BH crosscourt ×9; BH down the line rates higher · 0.25 pts
- Return of a 2nd serve, T, ad court hit BH inside-out ×1; BH inside-in rates higher · 0.24 pts
- Return +1: drive to your forehand side hit FH slice down the line ×2; FH slice crosscourt rates higher · 0.24 pts
- Rally, shots 5–8: slice to your middle, you at net hit FH volley through the middle ×1; FH volley crosscourt rates higher · 0.23 pts
Janice Tjen
4.7 points left on the table across 152 shots 3.06 per 100 shots
- Return of a 1st serve, T, deuce court hit FH through the middle ×6; FH inside-in rates higher · 0.38 pts
- Rally, shots 5–8: slice to your backhand side hit FH inside-out ×5; FH inside-in rates higher · 0.26 pts
- Return of a 1st serve, wide, ad court hit BH slice through the middle ×4; BH slice crosscourt rates higher · 0.24 pts
- Rally, shots 5–8: drive to your backhand side hit BH slice through the middle ×4; BH slice crosscourt rates higher · 0.24 pts