Beijing · R32 · Hard · 1 Oct 2019
Angelique Kerber v Polona Hercog
52–69 in points · Polona Hercog won
Why it went the way it did
Polona Hercog won 9.1 more points than Angelique Kerber relative to what the serve alone predicted. Angelique Kerber's biggest leaks: forehand execution −3.2, slice shot selection −3.1, backhand 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 | Angelique Kerber | Polona Hercog | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.2 | ±0.0 | −0.4 | −0.7 | ±0.0 | ±0.0 | −1.7 | −1.7 |
| Serve 2nd | −0.1 | ±0.0 | +0.3 | +0.2 | ±0.0 | ±0.0 | +0.4 | +0.4 |
| Return | −0.4 | +0.1 | −0.2 | −0.4 | −0.7 | −0.7 | +0.2 | −1.2 |
| Forehand | +0.4 | +0.2 | −3.2 | −2.6 | −0.3 | +1.2 | +0.6 | +1.4 |
| Backhand | −0.3 | −0.2 | −2.1 | −2.5 | +0.1 | +0.3 | +1.3 | +1.8 |
| Slice | −0.1 | −3.1 | −0.3 | −3.5 | −0.8 | −6.0 | +1.6 | −5.1 |
| Net | +0.1 | +0.1 | ±0.0 | +0.1 | +0.2 | +0.3 | +1.6 | +2.1 |
| Touch | ±0.0 | −0.6 | −0.7 | −1.3 | ±0.0 | +0.5 | +0.3 | +0.8 |
| All shots | −0.5 | −3.5 | −6.6 | −10.6 | −1.5 | −4.5 | +4.4 | −1.5 |
Set by set
| Set | Angelique Kerber | Polona Hercog | Net, Angelique | |
|---|---|---|---|---|
| 1 | −7.7 | −3.3 | −4.4 | |
| 2 | −2.9 | +1.8 | −4.7 |
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.
Angelique Kerber serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 50% 69% | 31% 50% | 19% 50% |
| 2 | 58% 63% | 27% 22% | 15% 60% |
Set to set +0.08 per 100 first serves in sets 2+
Within sets +2.94 per 100 first serves, every two to three service games
Polona Hercog serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 23% 67% | 23% 67% | 54% 86% |
| 2 | 33% 60% | 10% 67% | 57% 71% |
Within sets −0.04 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.
Angelique Kerber
7.3 points left on the table across 225 shots 3.24 per 100 shots
- Return of a 2nd serve, T, ad court hit BH down the line ×3; BH inside-in rates higher · 0.40 pts
- Return of a 2nd serve, wide, deuce court hit BH through the middle ×3; BH inside-out rates higher · 0.34 pts
- Long rally, 9+: slice to your middle hit BH slice down the line ×5; BH slice through the middle rates higher · 0.33 pts
- Return of a 1st serve, wide, ad court hit FH through the middle ×3; FH inside-out rates higher · 0.28 pts
Polona Hercog
8.1 points left on the table across 229 shots 3.54 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH slice down the line ×5; BH slice crosscourt rates higher · 0.44 pts
- Return of a 1st serve, wide, ad court hit BH slice down the line ×2; BH slice crosscourt rates higher · 0.35 pts
- Return +1: drive to your backhand side hit BH slice down the line ×3; BH slice crosscourt rates higher · 0.33 pts
- Return of a 2nd serve, T, deuce court hit FH through the middle ×7; FH inside-in rates higher · 0.33 pts