St Petersburg · R16 · Hard · 31 Jan 2019
Tereza Martincova v Ekaterina Alexandrova
53–71 in points · Ekaterina Alexandrova won
Why it went the way it did
Ekaterina Alexandrova won 8.6 more points than Tereza Martincova relative to what the serve alone predicted. Tereza Martincova's biggest leaks: forehand execution −3.7, backhand execution −1.7, net execution −1.7.
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 | Tereza Martincova | Ekaterina Alexandrova | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | +0.1 | ±0.0 | −0.2 | −0.2 | +0.4 | ±0.0 | −0.3 | +0.1 |
| Serve 2nd | ±0.0 | ±0.0 | −0.9 | −0.9 | +0.1 | ±0.0 | +0.7 | +0.7 |
| Return | −0.3 | −0.3 | −0.6 | −1.3 | +0.3 | +0.6 | −0.4 | +0.4 |
| Forehand | +0.1 | +2.0 | −3.7 | −1.6 | +0.6 | +1.2 | −1.7 | ±0.0 |
| Backhand | −0.2 | +0.6 | −1.7 | −1.3 | −0.2 | +0.6 | −0.1 | +0.3 |
| Slice | −0.1 | −1.2 | −0.3 | −1.6 | ±0.0 | −1.8 | −0.3 | −2.1 |
| Net | −0.1 | +0.1 | −1.7 | −1.7 | ±0.0 | ±0.0 | +1.0 | +0.9 |
| Touch | +0.1 | ±0.0 | −0.2 | −0.2 | ±0.0 | ±0.0 | −0.5 | −0.5 |
| All shots | −0.6 | +1.3 | −9.4 | −8.7 | +1.0 | +0.5 | −1.6 | −0.1 |
Set by set
| Set | Tereza Martincova | Ekaterina Alexandrova | Net, Tereza | |
|---|---|---|---|---|
| 1 | −3.6 | −0.2 | −3.4 | |
| 2 | −5.1 | +0.1 | −5.2 |
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.
Tereza Martincova serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 44% 59% | 21% 50% | 36% 57% |
| 2 | 45% 44% | 10% 0% | 45% 33% |
Set to set +0.53 per 100 first serves in sets 2+
Within sets +0.30 per 100 first serves, every two to three service games
Ekaterina Alexandrova serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 42% 64% | 3% 100% | 55% 67% |
| 2 | 56% 56% | 6% 50% | 38% 67% |
Set to set −0.48 per 100 first serves in sets 2+
Within sets −0.62 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.
Tereza Martincova
7.0 points left on the table across 235 shots 2.99 per 100 shots
- Return of a 2nd serve, wide, deuce court hit FH through the middle ×4; FH inside-out rates higher · 0.45 pts
- Long rally, 9+: drive to your forehand side, opponent at net, you at net hit FH volley down the line ×1; FH volley crosscourt rates higher · 0.35 pts
- Return +1: drive to your forehand side hit FH through the middle ×5; FH crosscourt rates higher · 0.32 pts
- Return +1: drive to your backhand side hit BH through the middle ×6; BH crosscourt rates higher · 0.29 pts
Ekaterina Alexandrova
5.4 points left on the table across 240 shots 2.25 per 100 shots
- Rally, shots 5–8: drive to your middle hit BH through the middle ×8; BH crosscourt rates higher · 0.38 pts
- Rally, shots 5–8: drive to your backhand side hit BH through the middle ×7; BH crosscourt rates higher · 0.30 pts
- Serve +1: mid-depth return to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.25 pts
- Long rally, 9+: volley to your backhand side, opponent at net hit BH through the middle ×1; BH down the line rates higher · 0.22 pts