Indian Wells · R64 · Hard · 8 Oct 2021
Iga Swiatek v Petra Martic
62–40 in points · Iga Swiatek won
Why it went the way it did
Iga Swiatek won 12.3 more points than Petra Martic relative to what the serve alone predicted. Petra Martic's biggest leaks: forehand execution −5.4, serve 1st execution −2.5, backhand execution −2.2.
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 | Petra Martic | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.1 | ±0.0 | −0.3 | −0.3 | +0.3 | ±0.0 | −2.5 | −2.2 |
| Serve 2nd | ±0.0 | ±0.0 | −0.1 | −0.1 | ±0.0 | ±0.0 | +1.4 | +1.4 |
| Return | +0.5 | ±0.0 | −0.4 | +0.1 | +0.2 | +0.5 | +1.8 | +2.5 |
| Forehand | +0.2 | +1.0 | +3.3 | +4.5 | +0.5 | +0.7 | −5.4 | −4.2 |
| Backhand | +0.1 | +0.2 | +0.7 | +1.1 | +0.4 | +0.3 | −2.2 | −1.5 |
| Slice | +0.1 | −0.6 | −0.1 | −0.7 | −0.4 | −1.4 | +0.1 | −1.8 |
| Net | ±0.0 | +0.2 | +0.2 | +0.5 | −0.1 | +0.3 | −0.2 | ±0.0 |
| Touch | +0.2 | −0.4 | +1.1 | +0.9 | +0.1 | +0.3 | −1.0 | −0.6 |
| All shots | +1.0 | +0.5 | +4.4 | +5.9 | +0.9 | +0.8 | −8.2 | −6.5 |
Set by set
| Set | Iga Swiatek | Petra Martic | Net, Iga | |
|---|---|---|---|---|
| 1 | +4.7 | −4.2 | +8.9 | |
| 2 | +1.2 | −2.3 | +3.5 |
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 | 35% 71% | 20% 100% | 45% 78% |
| 2 | 33% 50% | 22% 0% | 44% 63% |
Within sets −2.08 per 100 first serves, every two to three service games
Petra Martic serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 38% 42% | 13% 25% | 50% 50% |
| 2 | 58% 44% | 6% 50% | 35% 27% |
Set to set −0.59 per 100 first serves in sets 2+
Within sets ±0.00 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
3.4 points left on the table across 163 shots 2.09 per 100 shots
- Return of a 2nd serve, wide, deuce court hit FH crosscourt ×7; FH inside-out rates higher · 0.40 pts
- Return +1: drop shot to your forehand side hit FH through the middle ×1; FH down the line rates higher · 0.27 pts
- Serve +1: mid-depth return to your middle hit BH through the middle ×3; BH crosscourt rates higher · 0.18 pts
- Return of a 2nd serve, T, ad court hit FH through the middle ×2; FH inside-in rates higher · 0.16 pts
Petra Martic
3.2 points left on the table across 155 shots 2.05 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH slice down the line ×3; BH slice crosscourt rates higher · 0.26 pts
- Rally, shots 5–8: drive to your forehand side hit FH volley down the line ×1; FH volley crosscourt rates higher · 0.19 pts
- Serve +1: short return to your backhand side hit BH slice through the middle ×3; BH slice crosscourt rates higher · 0.19 pts
- Return +1: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.19 pts