US Open · R128 · Hard · 28 Aug 2023
Iga Swiatek v Rebecca Peterson
52–22 in points · Iga Swiatek won
Why it went the way it did
Iga Swiatek won 14.3 more points than Rebecca Peterson relative to what the serve alone predicted. Rebecca Peterson's biggest leaks: forehand execution −5.4, slice shot selection −0.9, touch shot selection −0.7.
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 | Iga Swiatek | Rebecca Peterson | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.1 | ±0.0 | +1.3 | +1.2 | ±0.0 | ±0.0 | −0.4 | −0.4 |
| Serve 2nd | ±0.0 | ±0.0 | +0.3 | +0.3 | ±0.0 | ±0.0 | +0.2 | +0.2 |
| Return | ±0.0 | +0.4 | +1.3 | +1.8 | +0.1 | +0.2 | +1.1 | +1.4 |
| Forehand | +0.7 | +1.3 | +1.1 | +3.1 | −0.1 | +1.1 | −5.4 | −4.3 |
| Backhand | +0.4 | +0.4 | +2.2 | +3.0 | ±0.0 | +0.7 | −0.3 | +0.5 |
| Slice | ±0.0 | ±0.0 | ±0.0 | ±0.0 | ±0.0 | −0.9 | ±0.0 | −1.0 |
| Net | +0.1 | +0.1 | −0.6 | −0.5 | ±0.0 | +0.1 | −0.2 | −0.1 |
| Touch | ±0.0 | +0.1 | +0.3 | +0.4 | +0.1 | −0.7 | −0.5 | −1.1 |
| All shots | +1.1 | +2.3 | +5.9 | +9.3 | +0.1 | +0.5 | −5.5 | −4.9 |
Set by set
| Set | Iga Swiatek | Rebecca Peterson | Net, Iga | |
|---|---|---|---|---|
| 1 | +5.5 | −3.1 | +8.6 | |
| 2 | +3.9 | −1.8 | +5.7 |
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.
Iga Swiatek serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 44% 86% | 44% 86% | 13% 0% |
| 2 | 50% 77% | 12% 67% | 38% 60% |
Within sets +2.46 per 100 first serves, every two to three service games
Rebecca Peterson serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 35% 17% | 24% 0% | 41% 43% |
| 2 | 33% 20% | 20% 67% | 47% 43% |
Within sets −0.23 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.
Iga Swiatek
2.1 points left on the table across 138 shots 1.54 per 100 shots
- Long rally, 9+: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.17 pts
- Long rally, 9+: drive to your backhand side, opponent at net hit BH lob down the line ×1; BH lob crosscourt rates higher · 0.15 pts
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×2; FH crosscourt rates higher · 0.11 pts
- Return of a 1st serve, wide, deuce court hit FH through the middle ×4; FH crosscourt rates higher · 0.10 pts
Rebecca Peterson
3.4 points left on the table across 145 shots 2.31 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH through the middle ×6; BH crosscourt rates higher · 0.26 pts
- Serve +1: mid-depth return to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.25 pts
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×4; FH crosscourt rates higher · 0.22 pts
- Rally, shots 5–8: drive to your backhand side hit FH through the middle ×2; FH inside-in rates higher · 0.21 pts