ITF Taizhou · F · Hard · 21 Jun 2025
Yidi Yang v Janice Tjen
61–77 in points · Janice Tjen won
Why it went the way it did
Janice Tjen won 9.9 more points than Yidi Yang relative to what the serve alone predicted. Yidi Yang's biggest leaks: forehand execution −5.0, backhand execution −3.0, slice shot selection −2.0.
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 | Yidi Yang | Janice Tjen | ||||||
|---|---|---|---|---|---|---|---|---|
| Dir | Sel | Exec | Total | Dir | Sel | Exec | Total | |
| Serve 1st | −0.4 | ±0.0 | −0.5 | −0.9 | +0.3 | ±0.0 | −0.7 | −0.4 |
| Serve 2nd | ±0.0 | ±0.0 | +0.5 | +0.5 | +0.1 | ±0.0 | +0.6 | +0.7 |
| Return | −0.3 | +0.7 | +0.5 | +0.9 | +0.5 | −3.1 | +2.2 | −0.5 |
| Forehand | −1.0 | +1.9 | −5.0 | −4.1 | +0.6 | +4.8 | −1.0 | +4.4 |
| Backhand | −0.5 | +0.9 | −3.0 | −2.6 | ±0.0 | +0.3 | −0.4 | −0.1 |
| Slice | −0.1 | −2.0 | −1.2 | −3.2 | +0.5 | −6.4 | +1.7 | −4.3 |
| Net | −0.1 | +0.2 | −0.1 | +0.1 | −0.1 | +0.6 | −0.3 | +0.2 |
| Touch | ±0.0 | ±0.0 | −0.2 | −0.2 | ±0.0 | +0.1 | +0.2 | +0.3 |
| All shots | −2.3 | +1.7 | −8.9 | −9.5 | +2.0 | −3.8 | +2.2 | +0.4 |
Set by set
| Set | Yidi Yang | Janice Tjen | Net, Yidi | |
|---|---|---|---|---|
| 1 | −6.6 | −2.6 | −4.0 | |
| 2 | −2.9 | +3.0 | −5.9 |
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.
Yidi Yang serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 40% 56% | 35% 57% | 25% 60% |
| 2 | 48% 55% | 29% 50% | 24% 20% |
Set to set +1.28 per 100 first serves in sets 2+
Within sets +2.01 per 100 first serves, every two to three service games
Janice Tjen serving
| Set | Wide | Body | T |
|---|---|---|---|
| 1 | 76% 64% | 9% 67% | 15% 100% |
| 2 | 48% 45% | 9% 50% | 43% 80% |
Set to set +2.24 per 100 first serves in sets 2+
Within sets +0.75 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.
Yidi Yang
9.5 points left on the table across 302 shots 3.15 per 100 shots
- Rally, shots 5–8: drive to your forehand side hit FH through the middle ×16; FH crosscourt rates higher · 0.87 pts
- Rally, shots 5–8: slice to your backhand side hit BH through the middle ×5; BH down the line rates higher · 0.54 pts
- Return of a 2nd serve, wide, deuce court hit FH through the middle ×4; FH inside-out rates higher · 0.45 pts
- Rally, shots 5–8: slice to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.38 pts
Janice Tjen
7.6 points left on the table across 317 shots 2.40 per 100 shots
- Rally, shots 5–8: drive to your backhand side hit BH slice through the middle ×9; BH slice crosscourt rates higher · 0.54 pts
- Return +1: drive to your middle hit FH through the middle ×5; FH down the line rates higher · 0.32 pts
- Rally, shots 5–8: drive to your backhand side hit FH through the middle ×3; FH inside-in rates higher · 0.32 pts
- Return of a 1st serve, wide, ad court hit BH slice through the middle ×5; BH slice crosscourt rates higher · 0.30 pts