Acapulco · QF · Hard · 28 Feb 2019
Saisai Zheng v Bianca Andreescu
70–86 in points · result not charted to completion
Why it went the way it did
Bianca Andreescu won 6.4 more points than Saisai Zheng relative to what the serve alone predicted. Saisai Zheng's biggest leaks: forehand execution −4.3, slice shot selection −3.1, return 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 | Saisai Zheng | Bianca Andreescu | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.2 | ±0.0 | −1.8 | −1.7 | −0.5 | ±0.0 | −1.8 | −2.4 |
| Serve 2nd | −0.1 | ±0.0 | +0.5 | +0.4 | −0.1 | ±0.0 | +1.0 | +0.9 |
| Return | −0.5 | −1.1 | −2.1 | −3.7 | −0.3 | −0.3 | +1.5 | +0.9 |
| Forehand | −1.9 | +1.9 | −4.3 | −4.4 | −0.6 | +2.7 | −0.4 | +1.7 |
| Backhand | −0.6 | +1.3 | −0.2 | +0.5 | +0.1 | +0.6 | −4.4 | −3.7 |
| Slice | −0.3 | −3.1 | +0.1 | −3.3 | −0.1 | −2.6 | −1.5 | −4.3 |
| Net | −0.4 | +0.2 | −0.6 | −0.8 | −0.4 | +0.6 | −1.4 | −1.2 |
| Touch | +0.3 | −1.2 | −1.0 | −1.9 | −0.2 | −0.2 | ±0.0 | −0.4 |
| All shots | −3.2 | −2.2 | −9.5 | −14.9 | −2.1 | +0.7 | −7.0 | −8.5 |
Set by set
| Set | Saisai Zheng | Bianca Andreescu | Net, Saisai | |
|---|---|---|---|---|
| 1 | −6.3 | −6.1 | −0.1 | |
| 2 | −8.6 | −2.3 | −6.3 |
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.
Saisai Zheng serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 56% 68% | 13% 67% | 31% 43% |
| 2 | 38% 56% | 21% 20% | 42% 50% |
Set to set −1.77 per 100 first serves in sets 2+
Within sets +0.11 per 100 first serves, every two to three service games
Bianca Andreescu serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 36% 76% | 34% 50% | 31% 50% |
| 2 | 46% 67% | 31% 75% | 23% 67% |
Set to set −0.31 per 100 first serves in sets 2+
Within sets +0.20 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.
Saisai Zheng
12.2 points left on the table across 303 shots 4.04 per 100 shots
- Rally, shots 5–8: drive to your middle hit FH through the middle ×10; FH crosscourt rates higher · 0.70 pts
- Return +1: drive to your middle hit FH through the middle ×10; FH down the line rates higher · 0.64 pts
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×7; FH crosscourt rates higher · 0.38 pts
- Return +1: drive to your forehand side hit FH through the middle ×6; FH crosscourt rates higher · 0.38 pts
Bianca Andreescu
10.5 points left on the table across 297 shots 3.52 per 100 shots
- Rally, shots 5–8: drive to your middle, you at net hit FH volley through the middle ×3; FH volley crosscourt rates higher · 0.72 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×7; FH crosscourt rates higher · 0.49 pts
- Rally, shots 5–8: drive to your backhand side, you at net hit BH volley through the middle ×2; BH volley crosscourt rates higher · 0.42 pts
- Serve +1: mid-depth return to your backhand side hit FH through the middle ×3; FH inside-in rates higher · 0.42 pts