Tokyo · SF · Hard · 26 Oct 2024
Katie Boulter v Sofia Kenin
55–67 in points · Sofia Kenin won
Why it went the way it did
Sofia Kenin won 6.3 more points than Katie Boulter relative to what the serve alone predicted. Katie Boulter's biggest leaks: slice shot selection −1.8, serve 1st execution −1.1, serve 2nd execution −1.0.
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 | Katie Boulter | Sofia Kenin | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.2 | ±0.0 | −1.1 | −0.9 | +0.3 | ±0.0 | +0.8 | +1.0 |
| Serve 2nd | +0.1 | ±0.0 | −1.0 | −0.9 | ±0.0 | ±0.0 | +1.1 | +1.2 |
| Return | +0.2 | −0.5 | +0.8 | +0.4 | ±0.0 | −1.1 | −0.9 | −2.0 |
| Forehand | −0.3 | +1.3 | +5.4 | +6.4 | +0.3 | +0.7 | +0.6 | +1.5 |
| Backhand | −0.5 | +0.9 | +0.3 | +0.7 | +0.4 | +0.6 | +6.6 | +7.5 |
| Slice | −0.1 | −1.8 | +0.6 | −1.3 | ±0.0 | −1.5 | +0.5 | −1.0 |
| Net | ±0.0 | +0.3 | +0.9 | +1.2 | +0.1 | ±0.0 | +1.1 | +1.3 |
| Touch | ±0.0 | ±0.0 | −1.0 | −0.9 | +0.1 | ±0.0 | +1.4 | +1.4 |
| All shots | −0.4 | +0.1 | +4.9 | +4.6 | +1.2 | −1.4 | +11.1 | +10.9 |
Set by set
| Set | Katie Boulter | Sofia Kenin | Net, Katie | |
|---|---|---|---|---|
| 1 | +4.3 | +7.3 | −3.0 | |
| 2 | +0.3 | +3.6 | −3.3 |
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.
Katie Boulter serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 57% 60% | 11% 25% | 31% 55% |
| 2 | 39% 82% | 14% 50% | 46% 54% |
Set to set −0.75 per 100 first serves in sets 2+
Within sets −0.14 per 100 first serves, every two to three service games
Sofia Kenin serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 48% 77% | 11% 100% | 41% 36% |
| 2 | 61% 74% | 10% 100% | 29% 67% |
Set to set +1.53 per 100 first serves in sets 2+
Within sets +0.38 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.
Katie Boulter
5.5 points left on the table across 202 shots 2.73 per 100 shots
- Serve +1: mid-depth return to your middle hit FH through the middle ×4; FH crosscourt rates higher · 0.34 pts
- Rally, shots 5–8: drive to your backhand side hit BH through the middle ×7; BH crosscourt rates higher · 0.30 pts
- Return of a 1st serve, T, deuce court hit BH down the line ×4; BH through the middle rates higher · 0.27 pts
- Rally, shots 5–8: drop shot to your forehand side hit FH through the middle ×1; FH crosscourt rates higher · 0.24 pts
Sofia Kenin
4.6 points left on the table across 199 shots 2.31 per 100 shots
- Return of a 2nd serve, T, ad court hit FH through the middle ×5; FH inside-in rates higher · 0.41 pts
- Return of a 2nd serve, wide, deuce court hit FH through the middle ×3; FH inside-out rates higher · 0.34 pts
- Rally, shots 5–8: volley to your middle, opponent at net hit FH through the middle ×1; FH crosscourt rates higher · 0.24 pts
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.16 pts