RallyIQ

Olympics · R32 · Clay · 29 Jul 2024

Iga Swiatek v Diane Parry

61–34 in points · Iga Swiatek won

Why it went the way it did

Iga Swiatek won 14.2 more points than Diane Parry relative to what the serve alone predicted. Diane Parry's biggest leaks: slice shot selection −6.1, forehand execution −3.7, slice execution −2.5.

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 SwiatekDiane Parry
DirSelExecTotalDirSelExecTotal
Serve 1st ±0.0 ±0.0 +0.8 +0.8 +0.3 ±0.0 −1.0 −0.8
Serve 2nd ±0.0 ±0.0 +0.7 +0.7 ±0.0 ±0.0 −0.4 −0.4
Return +0.1 +0.2 −1.0 −0.7 +0.1 −1.0 −0.3 −1.3
Forehand ±0.0 +1.0 −2.4 −1.4 ±0.0 +1.1 −3.7 −2.6
Backhand +0.2 −0.3 +3.2 +3.1 −0.1 +0.3 −0.1 ±0.0
Slice −0.2 −1.1 +0.4 −0.8 −0.1 −6.1 −2.5 −8.6
Net −0.4 ±0.0 −1.0 −1.3 −0.1 +0.2 +0.2 +0.3
Touch −0.1 −0.4 ±0.0 −0.5 ±0.0 −0.3 −0.7 −1.0
All shots −0.3−0.6 +0.8−0.1 ±0.0−5.9 −8.5−14.4

Set by set

SetIga SwiatekDiane ParryNet, Iga
1+0.5−6.3 +6.8
2−0.6−8.0 +7.4

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 52% 82% 14% 33% 33% 71%
2 33% 80% 33% 100% 33% 60%

Within sets −2.28 per 100 first serves, every two to three service games

Diane Parry serving

SetWideBodyT
1 50% 54% 8% 100% 42% 18%
2 50% 50% 13% 0% 38% 50%

Within sets −0.33 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

4.6 points left on the table across 193 shots 2.38 per 100 shots

  1. Return +1: slice to your middle hit BH through the middle ×2; BH down the line rates higher · 0.28 pts
  2. Rally, shots 5–8: drive to your middle, you at net hit FH volley through the middle ×1; FH volley crosscourt rates higher · 0.24 pts
  3. Rally, shots 5–8: drive to your backhand side hit BH through the middle ×5; BH crosscourt rates higher · 0.21 pts
  4. Rally, shots 5–8: smash to your middle, opponent at net hit FH through the middle ×1; FH crosscourt rates higher · 0.19 pts

Diane Parry

5.5 points left on the table across 192 shots 2.85 per 100 shots

  1. Serve +1: mid-depth return to your backhand side hit BH slice down the line ×3; BH slice crosscourt rates higher · 0.39 pts
  2. Rally, shots 5–8: drive to your forehand side hit FH through the middle ×5; FH crosscourt rates higher · 0.27 pts
  3. Rally, shots 5–8: lob to your middle, you at net hit Smash through the middle ×1; Smash crosscourt rates higher · 0.25 pts
  4. Rally, shots 5–8: drive to your middle hit FH through the middle ×3; FH crosscourt rates higher · 0.21 pts