RallyIQ

Doha · R16 · Hard · 15 Feb 2023

Iga Swiatek v Danielle Collins

53–20 in points · Iga Swiatek won

Why it went the way it did

Iga Swiatek won 15.4 more points than Danielle Collins relative to what the serve alone predicted. Danielle Collins's biggest leaks: return execution −4.0, forehand execution −3.8.

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.

ShotIga SwiatekDanielle Collins
DirSelExecTotalDirSelExecTotal
Serve 1st −0.6 ±0.0 +1.1 +0.5 +0.1 ±0.0 −0.4 −0.3
Serve 2nd −0.1 ±0.0 −0.2 −0.2 ±0.0 ±0.0 −0.3 −0.3
Return ±0.0 +0.4 +3.7 +4.2 ±0.0 +0.3 −4.0 −3.7
Forehand −0.2 +0.4 +2.3 +2.6 +0.1 +0.4 −3.8 −3.3
Backhand ±0.0 +0.3 ±0.0 +0.2 +0.5 +0.1 −0.4 +0.2
Slice −0.1 −0.9 +0.3 −0.7 −0.1 −0.5 −0.4 −0.9
Touch ±0.0 ±0.0 ±0.0 ±0.0 −0.1 −0.2 −0.3 −0.5
All shots −0.9+0.2 +7.3+6.6 +0.7+0.2 −9.7−8.8

Set by set

SetIga SwiatekDanielle CollinsNet, Iga
1+1.6−8.3 +9.8
2+5.0−0.5 +5.5

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

SetWideBodyT
1 20% 100% 67% 70% 13% 100%
2 34% 80% 45% 69% 21% 50%

Within sets +1.60 per 100 first serves, every two to three service games

Danielle Collins serving

SetWideBodyT
1 46% 0% 8% 0% 46% 17%
2 50% 38% 13% 50% 38% 50%

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

2.6 points left on the table across 104 shots 2.54 per 100 shots

  1. Rally, shots 5–8: drive to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.21 pts
  2. Serve +1: deep return to your middle hit BH down the line ×3; BH crosscourt rates higher · 0.21 pts
  3. Return of a 1st serve, wide, deuce court hit FH through the middle ×7; FH crosscourt rates higher · 0.18 pts
  4. Return +1: drive to your backhand side hit BH slice through the middle ×2; BH slice crosscourt rates higher · 0.13 pts

Danielle Collins

2.3 points left on the table across 127 shots 1.82 per 100 shots

  1. Rally, shots 5–8: drive to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.21 pts
  2. Rally, shots 5–8: drive to your forehand side hit FH through the middle ×3; FH crosscourt rates higher · 0.16 pts
  3. Return +1: drive to your forehand side hit FH down the line ×3; FH crosscourt rates higher · 0.10 pts
  4. Return +1: drive to your forehand side hit FH lob down the line ×1; FH lob crosscourt rates higher · 0.10 pts