New Haven · R16 · Hard · 26 Aug 2015
Petra Kvitova v Madison Keys
87–73 in points · Petra Kvitova won
Why it went the way it did
Petra Kvitova won 6.2 more points than Madison Keys relative to what the serve alone predicted. Madison Keys's biggest leaks: backhand execution −4.6, return execution −4.4, forehand execution −3.6.
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 | Petra Kvitova | Madison Keys | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.5 | ±0.0 | −1.0 | −0.5 | +0.1 | ±0.0 | −1.4 | −1.4 |
| Serve 2nd | −0.1 | ±0.0 | −0.3 | −0.3 | +0.1 | ±0.0 | +1.9 | +2.0 |
| Return | −0.3 | −0.6 | −2.1 | −2.9 | −0.4 | −0.8 | −4.4 | −5.5 |
| Forehand | −0.4 | +1.4 | −2.4 | −1.4 | −1.0 | +1.1 | −3.6 | −3.6 |
| Backhand | ±0.0 | −0.1 | −3.6 | −3.7 | −0.5 | +0.3 | −4.6 | −4.8 |
| Slice | +0.1 | −0.7 | −0.1 | −0.7 | −0.4 | −1.3 | −0.4 | −2.1 |
| Net | −0.3 | +0.6 | −0.5 | −0.2 | +0.1 | ±0.0 | +0.4 | +0.5 |
| Touch | ±0.0 | ±0.0 | ±0.0 | ±0.0 | −0.1 | −1.0 | +0.1 | −1.0 |
| All shots | −0.4 | +0.6 | −9.9 | −9.7 | −2.2 | −1.7 | −12.1 | −16.0 |
Set by set
| Set | Petra Kvitova | Madison Keys | Net, Petra | |
|---|---|---|---|---|
| 1 | −7.4 | −3.5 | −4.0 | |
| 2 | −0.6 | −7.2 | +6.6 | |
| 3 | −1.7 | −5.4 | +3.7 |
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.
Petra Kvitova serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 33% 63% | 8% 50% | 58% 71% |
| 2 | 46% 75% | 8% 50% | 46% 67% |
| 3 | 51% 56% | – | 49% 71% |
Set to set −0.37 per 100 first serves in sets 2+
Within sets +0.14 per 100 first serves, every two to three service games
Madison Keys serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 35% 63% | 17% 100% | 48% 91% |
| 2 | 46% 46% | 18% 40% | 36% 50% |
| 3 | 41% 33% | 18% 50% | 41% 67% |
Set to set −0.95 per 100 first serves in sets 2+
Within sets −0.05 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.
Petra Kvitova
8.5 points left on the table across 227 shots 3.75 per 100 shots
- Rally, shots 5–8: drive to your middle hit FH through the middle ×9; FH crosscourt rates higher · 0.63 pts
- Return of a 2nd serve, wide, deuce court hit BH crosscourt ×4; BH inside-out rates higher · 0.51 pts
- Return of a 1st serve, wide, ad court hit FH through the middle ×5; FH inside-out rates higher · 0.47 pts
- Return of a 2nd serve, wide, deuce court hit BH through the middle ×4; BH inside-out rates higher · 0.46 pts
Madison Keys
8.1 points left on the table across 238 shots 3.42 per 100 shots
- Return +1: drive to your forehand side hit FH through the middle ×7; FH crosscourt rates higher · 0.44 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×6; FH crosscourt rates higher · 0.42 pts
- Serve +1: deep return to your middle hit FH through the middle ×6; FH crosscourt rates higher · 0.36 pts
- Rally, shots 5–8: drive to your middle hit BH through the middle ×7; BH crosscourt rates higher · 0.33 pts