Davis Cup Finals · RR · Hard · 28 Nov 2021
Nicolas Mejia v Frances Tiafoe
98–109 in points · Frances Tiafoe won
Why it went the way it did
Frances Tiafoe won 5.9 more points than Nicolas Mejia relative to what the serve alone predicted. Nicolas Mejia's biggest leaks: slice shot selection −4.3, return execution −1.6, forehand direction choices −1.6.
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 | Nicolas Mejia | Frances Tiafoe | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.2 | −0.2 | −1.2 | −1.6 | ±0.0 | −0.2 | −1.4 | −1.6 |
| Serve 2nd | +0.1 | ±0.0 | −0.1 | ±0.0 | ±0.0 | ±0.0 | ±0.0 | ±0.0 |
| Return | −0.1 | +1.2 | −1.6 | −0.5 | +0.2 | +0.5 | −0.9 | −0.2 |
| Forehand | −1.6 | +2.3 | −0.4 | +0.3 | ±0.0 | +5.1 | −2.7 | +2.4 |
| Backhand | +0.5 | +1.9 | −1.2 | +1.3 | +0.5 | +0.9 | +1.6 | +3.1 |
| Slice | −0.4 | −4.3 | −0.2 | −4.9 | ±0.0 | −2.3 | −1.0 | −3.2 |
| Net | −0.1 | ±0.0 | +0.4 | +0.4 | −0.4 | +0.4 | +0.8 | +0.8 |
| Touch | +0.1 | −0.7 | +1.1 | +0.5 | ±0.0 | −0.1 | +0.2 | +0.1 |
| All shots | −1.7 | +0.3 | −3.1 | −4.5 | +0.4 | +4.4 | −3.4 | +1.4 |
Set by set
| Set | Nicolas Mejia | Frances Tiafoe | Net, Nicolas | |
|---|---|---|---|---|
| 1 | +1.5 | +0.2 | +1.4 | |
| 2 | −3.9 | +2.7 | −6.6 | |
| 3 | −2.1 | −1.4 | −0.7 |
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.
Nicolas Mejia serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 52% 69% | 6% 50% | 42% 69% |
| 2 | 50% 54% | 15% 25% | 35% 56% |
| 3 | 52% 60% | 13% 83% | 35% 76% |
Set to set +0.79 per 100 first serves in sets 2+
Within sets +0.74 per 100 first serves, every two to three service games
Frances Tiafoe serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 43% 69% | 10% 33% | 47% 64% |
| 2 | 41% 89% | 18% 50% | 41% 78% |
| 3 | 48% 75% | 6% 67% | 46% 65% |
Set to set +0.98 per 100 first serves in sets 2+
Within sets +0.81 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.
Nicolas Mejia
11.6 points left on the table across 414 shots 2.81 per 100 shots
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×12; FH crosscourt rates higher · 0.61 pts
- Long rally, 9+: drive to your forehand side hit FH through the middle ×8; FH crosscourt rates higher · 0.44 pts
- Serve +1: mid-depth return to your middle hit FH through the middle ×5; FH crosscourt rates higher · 0.43 pts
- Serve +1: deep return to your middle hit FH through the middle ×5; FH crosscourt rates higher · 0.37 pts
Frances Tiafoe
9.6 points left on the table across 419 shots 2.30 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH slice through the middle ×4; BH slice crosscourt rates higher · 0.29 pts
- Return +1: drive to your forehand side hit FH through the middle ×5; FH crosscourt rates higher · 0.29 pts
- Rally, shots 5–8: drive to your forehand side, you at net hit FH volley through the middle ×1; FH volley crosscourt rates higher · 0.28 pts
- Rally, shots 5–8: drive to your backhand side, you at net hit BH volley through the middle ×1; BH volley crosscourt rates higher · 0.26 pts