Indian Wells · R64 · Hard · 10 Mar 2022
Shuai Zhang v Daria Saville
57–71 in points · Daria Saville won
Why it went the way it did
Daria Saville won 5.2 more points than Shuai Zhang relative to what the serve alone predicted. Shuai Zhang's biggest leaks: return execution −2.0, forehand direction choices −1.9, slice shot selection −1.6.
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 | Shuai Zhang | Daria Saville | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.6 | ±0.0 | −0.9 | −1.5 | −1.2 | ±0.0 | +0.4 | −0.8 |
| Serve 2nd | ±0.0 | ±0.0 | −0.7 | −0.8 | ±0.0 | ±0.0 | −0.3 | −0.3 |
| Return | +0.4 | +0.5 | −2.0 | −1.0 | +0.2 | −0.7 | +0.4 | −0.1 |
| Forehand | −1.9 | +0.9 | −1.3 | −2.3 | −2.4 | +1.3 | +4.6 | +3.5 |
| Backhand | −0.4 | −1.3 | −0.6 | −2.3 | −0.6 | +0.1 | +0.7 | +0.2 |
| Slice | +0.1 | −1.6 | −0.5 | −2.0 | −0.4 | −4.9 | +1.0 | −4.3 |
| Net | −0.2 | +2.0 | +1.6 | +3.4 | −0.1 | +0.6 | −0.2 | +0.4 |
| Touch | −0.2 | −0.1 | −0.3 | −0.7 | −0.3 | −0.4 | +0.2 | −0.6 |
| All shots | −2.9 | +0.5 | −4.8 | −7.2 | −4.7 | −4.0 | +6.8 | −2.0 |
Set by set
| Set | Shuai Zhang | Daria Saville | Net, Shuai | |
|---|---|---|---|---|
| 1 | −3.1 | −0.8 | −2.3 | |
| 2 | −4.1 | −1.2 | −2.9 |
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.
Shuai Zhang serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 15% 20% | 52% 65% | 33% 36% |
| 2 | 32% 50% | 37% 29% | 32% 67% |
Set to set −1.64 per 100 first serves in sets 2+
Within sets −1.28 per 100 first serves, every two to three service games
Daria Saville serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 22% 88% | 50% 67% | 28% 10% |
| 2 | 18% 57% | 58% 57% | 25% 70% |
Set to set +0.57 per 100 first serves in sets 2+
Within sets +0.41 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.
Shuai Zhang
10.0 points left on the table across 293 shots 3.40 per 100 shots
- Rally, shots 5–8: drive to your middle hit FH through the middle ×11; FH crosscourt rates higher · 0.77 pts
- Serve +1: drive to your middle hit FH through the middle ×6; FH down the line rates higher · 0.64 pts
- Return +1: drive to your middle hit FH through the middle ×8; FH down the line rates higher · 0.52 pts
- Long rally, 9+: drive to your middle hit FH through the middle ×7; FH down the line rates higher · 0.49 pts
Daria Saville
10.6 points left on the table across 265 shots 4.02 per 100 shots
- Serve +1: drive to your middle hit FH through the middle ×19; FH down the line rates higher · 2.02 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×12; FH crosscourt rates higher · 0.84 pts
- Rally, shots 5–8: drive to your middle hit BH slice through the middle ×12; BH slice crosscourt rates higher · 0.56 pts
- Rally, shots 5–8: drive to your backhand side hit BH slice through the middle ×8; BH slice crosscourt rates higher · 0.48 pts