Australian Open · R32 · Hard · 20 Jan 2024
Sloane Stephens v Anna Kalinskaya
107–121 in points · Anna Kalinskaya won
Why it went the way it did
Anna Kalinskaya won 6.4 more points than Sloane Stephens relative to what the serve alone predicted. Sloane Stephens's biggest leaks: slice shot selection −4.4, forehand direction choices −0.5.
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 | Sloane Stephens | Anna Kalinskaya | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.5 | ±0.0 | +0.8 | +1.3 | −0.2 | ±0.0 | +1.2 | +0.9 |
| Serve 2nd | +0.2 | ±0.0 | +1.4 | +1.6 | +0.2 | ±0.0 | +1.8 | +2.0 |
| Return | +0.3 | ±0.0 | +3.3 | +3.6 | +0.2 | +1.0 | +5.1 | +6.4 |
| Forehand | −0.5 | +4.2 | +3.3 | +7.0 | ±0.0 | +2.6 | +9.8 | +12.5 |
| Backhand | −0.1 | +2.6 | +5.3 | +7.8 | +1.0 | +2.3 | +7.4 | +10.7 |
| Slice | +0.4 | −4.4 | +1.1 | −2.9 | +0.4 | −4.0 | −2.3 | −5.9 |
| Net | +0.2 | ±0.0 | +1.6 | +1.8 | −0.2 | +0.9 | +0.3 | +1.1 |
| Touch | +0.1 | +0.1 | +0.8 | +1.0 | −0.1 | −0.9 | +1.1 | +0.1 |
| All shots | +1.1 | +2.5 | +17.7 | +21.4 | +1.3 | +2.0 | +24.5 | +27.8 |
Set by set
| Set | Sloane Stephens | Anna Kalinskaya | Net, Sloane | |
|---|---|---|---|---|
| 1 | +11.7 | +10.1 | +1.6 | |
| 2 | +1.9 | +7.2 | −5.3 | |
| 3 | +7.8 | +10.5 | −2.7 |
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.
Sloane Stephens serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 59% 67% | 11% 80% | 30% 71% |
| 2 | 67% 61% | 7% 50% | 26% 14% |
| 3 | 46% 41% | 16% 33% | 38% 71% |
Set to set +1.05 per 100 first serves in sets 2+
Within sets +0.61 per 100 first serves, every two to three service games
Anna Kalinskaya serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 45% 67% | 34% 63% | 21% 70% |
| 2 | 63% 74% | 20% 33% | 17% 80% |
| 3 | 51% 57% | 17% 100% | 32% 38% |
Set to set +0.22 per 100 first serves in sets 2+
Within sets −0.53 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.
Sloane Stephens
12.6 points left on the table across 527 shots 2.40 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH through the middle ×18; BH crosscourt rates higher · 0.77 pts
- Rally, shots 5–8: drive to your middle hit FH through the middle ×10; FH crosscourt rates higher · 0.70 pts
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×11; FH crosscourt rates higher · 0.60 pts
- Return +1: drive to your middle hit FH through the middle ×9; FH down the line rates higher · 0.58 pts
Anna Kalinskaya
11.5 points left on the table across 518 shots 2.21 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 +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 backhand side hit BH through the middle ×10; BH crosscourt rates higher · 0.43 pts
- Return of a 1st serve, wide, deuce court hit FH through the middle ×16; FH crosscourt rates higher · 0.40 pts