RallyIQ

Chennai · QF · Hard · 31 Oct 2025

Donna Vekic v Kimberly Birrell

31–58 in points · Kimberly Birrell won

Why it went the way it did

Kimberly Birrell won 13.7 more points than Donna Vekic relative to what the serve alone predicted. Donna Vekic's biggest leaks: backhand execution −2.6, forehand execution −2.2, serve 2nd execution −1.8.

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.

ShotDonna VekicKimberly Birrell
DirSelExecTotalDirSelExecTotal
Serve 1st +0.2 ±0.0 −0.2 ±0.0 ±0.0 ±0.0 +0.2 +0.2
Serve 2nd ±0.0 ±0.0 −1.8 −1.8 ±0.0 ±0.0 −0.1 −0.1
Return −0.2 +0.6 −1.6 −1.2 +0.2 +0.3 −0.8 −0.3
Forehand −0.1 +0.7 −2.2 −1.6 −0.2 +0.6 +3.3 +3.7
Backhand ±0.0 +0.2 −2.6 −2.4 −0.1 −0.1 +1.2 +1.0
Slice ±0.0 −0.4 −0.2 −0.6 ±0.0 −0.1 −0.3 −0.4
Net ±0.0 ±0.0 ±0.0 ±0.0 ±0.0 +0.3 −0.2 ±0.0
Touch +0.2 −1.6 −0.9 −2.3 ±0.0 −0.3 −0.1 −0.4
All shots +0.1−0.5 −9.6−9.9 −0.1+0.6 +3.2+3.8

Set by set

SetDonna VekicKimberly BirrellNet, Donna
1−4.0+1.9 −5.9
2−6.0+1.9 −7.9

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.

Donna Vekic serving

SetWideBodyT
1 48% 62% 11% 0% 41% 82%
2 53% 20% 11% 0% 37% 43%

Within sets −0.30 per 100 first serves, every two to three service games

Kimberly Birrell serving

SetWideBodyT
1 36% 100% 27% 83% 36% 88%
2 43% 89% 10% 50% 48% 50%

Within sets +0.51 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.

Donna Vekic

3.2 points left on the table across 131 shots 2.41 per 100 shots

  1. Serve +1: mid-depth return to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.20 pts
  2. Return +1: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.19 pts
  3. Serve +1: short return to your backhand side hit BH through the middle ×2; BH down the line rates higher · 0.17 pts
  4. Long rally, 9+: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.17 pts

Kimberly Birrell

3.5 points left on the table across 127 shots 2.74 per 100 shots

  1. Rally, shots 5–8: drive to your backhand side hit BH through the middle ×6; BH crosscourt rates higher · 0.26 pts
  2. Long rally, 9+: slice to your middle hit FH through the middle + approach ×1; FH down the line + approach rates higher · 0.26 pts
  3. Rally, shots 5–8: lob to your middle hit BH crosscourt ×1; BH down the line rates higher · 0.20 pts
  4. Serve +1: mid-depth return to your middle hit BH through the middle ×3; BH crosscourt rates higher · 0.18 pts