US Open · R32 · Hard · 1 Sep 2023
Rinky Hijikata v Zhizhen Zhang
134–120 in points · Rinky Hijikata won
Why it went the way it did
Rinky Hijikata won 9.1 more points than Zhizhen Zhang relative to what the serve alone predicted. Zhizhen Zhang's biggest leaks: net execution −5.1, forehand execution −4.3, slice shot selection −2.3.
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 | Rinky Hijikata | Zhizhen Zhang | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.2 | +0.1 | −1.0 | −0.7 | −0.4 | −0.3 | −2.2 | −2.8 |
| Serve 2nd | +0.1 | ±0.0 | −0.6 | −0.5 | −0.1 | −0.1 | +1.1 | +1.0 |
| Return | −0.1 | +1.5 | +1.7 | +3.1 | +0.3 | +0.7 | +3.5 | +4.5 |
| Forehand | −0.6 | +4.7 | +1.1 | +5.3 | −0.6 | +3.4 | −4.3 | −1.5 |
| Backhand | −0.2 | +0.9 | −0.4 | +0.3 | −0.7 | +0.6 | −1.4 | −1.4 |
| Slice | −0.1 | −1.2 | −0.4 | −1.7 | ±0.0 | −2.3 | +1.9 | −0.5 |
| Net | +0.1 | +0.5 | −2.5 | −1.9 | +0.2 | ±0.0 | −5.1 | −4.9 |
| Touch | ±0.0 | −0.4 | −0.2 | −0.6 | +0.1 | −0.1 | −0.2 | −0.2 |
| All shots | −0.5 | +6.1 | −2.2 | +3.3 | −1.1 | +2.0 | −6.7 | −5.7 |
Set by set
| Set | Rinky Hijikata | Zhizhen Zhang | Net, Rinky | |
|---|---|---|---|---|
| 1 | +2.5 | −0.8 | +3.3 | |
| 2 | +2.4 | −2.0 | +4.4 | |
| 3 | −1.5 | −0.9 | −0.6 | |
| 4 | −0.2 | −2.0 | +1.9 |
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.
Rinky Hijikata serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 38% 83% | 9% 67% | 53% 59% |
| 2 | 39% 78% | 4% 0% | 57% 69% |
| 3 | 47% 56% | 6% 0% | 47% 44% |
| 4 | 48% 60% | 6% 0% | 45% 71% |
Set to set +0.53 per 100 first serves in sets 2+
Within sets −0.25 per 100 first serves, every two to three service games
Zhizhen Zhang serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 39% 50% | 16% 100% | 45% 50% |
| 2 | 28% 60% | 14% 40% | 58% 57% |
| 3 | 40% 47% | 9% 50% | 51% 58% |
| 4 | 35% 57% | 25% 40% | 40% 50% |
Set to set −0.45 per 100 first serves in sets 2+
Within sets +0.12 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.
Rinky Hijikata
11.5 points left on the table across 493 shots 2.33 per 100 shots
- Return +1: drive to your forehand side hit FH through the middle ×11; FH crosscourt rates higher · 0.64 pts
- Serve +1: deep return to your middle hit FH through the middle ×6; FH crosscourt rates higher · 0.44 pts
- Serve +1: mid-depth return to your middle hit FH through the middle ×5; FH crosscourt rates higher · 0.43 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×7; FH crosscourt rates higher · 0.40 pts
Zhizhen Zhang
11.3 points left on the table across 473 shots 2.38 per 100 shots
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×14; FH crosscourt rates higher · 0.71 pts
- Rally, shots 5–8: drive to your backhand side hit BH through the middle ×15; BH crosscourt rates higher · 0.58 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×9; FH crosscourt rates higher · 0.51 pts
- Serve +1: mid-depth return to your middle hit FH through the middle ×5; FH crosscourt rates higher · 0.43 pts