RallyIQ

Roland Garros · R16 · Clay · 31 May 2026

Marta Kostyuk v Iga Swiatek

79–57 in points · Marta Kostyuk won

Why it went the way it did

Marta Kostyuk won 9.3 more points than Iga Swiatek relative to what the serve alone predicted. Iga Swiatek's biggest leaks: forehand execution −5.3, return execution −2.3, serve 2nd execution −1.2.

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.

ShotMarta KostyukIga Swiatek
DirSelExecTotalDirSelExecTotal
Serve 1st +0.4 ±0.0 +1.6 +2.0 −0.1 ±0.0 −0.4 −0.5
Serve 2nd ±0.0 ±0.0 −0.1 −0.2 ±0.0 ±0.0 −1.2 −1.2
Return +0.1 +0.5 +0.8 +1.4 +0.2 +0.2 −2.3 −1.8
Forehand −0.1 +1.2 −0.4 +0.7 −0.1 +1.9 −5.3 −3.5
Backhand +0.1 +0.9 −0.1 +0.8 +0.3 +1.2 −0.5 +1.0
Slice −0.2 −1.0 +0.7 −0.5 −0.1 −0.6 +0.1 −0.6
Net −0.2 +0.5 −0.2 +0.1 −0.2 +1.0 −0.4 +0.4
Touch +0.1 −1.3 −0.3 −1.5 +0.1 −0.3 ±0.0 −0.2
All shots +0.2+0.7 +2.0+2.9 +0.2+3.4 −9.9−6.4

Set by set

SetMarta KostyukIga SwiatekNet, Marta
1−1.2−4.4 +3.2
2+4.1−2.0 +6.1

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.

Marta Kostyuk serving

SetWideBodyT
1 44% 45% 12% 67% 44% 64%
2 50% 57% 4% 0% 46% 69%

Set to set +0.35 per 100 first serves in sets 2+

Within sets −0.88 per 100 first serves, every two to three service games

Iga Swiatek serving

SetWideBodyT
1 56% 75% 22% 25% 22% 0%
2 52% 27% 29% 33% 19% 50%

Set to set −0.21 per 100 first serves in sets 2+

Within sets −0.47 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.

Marta Kostyuk

5.8 points left on the table across 232 shots 2.52 per 100 shots

  1. Rally, shots 5–8: drive to your middle hit FH through the middle ×8; FH crosscourt rates higher · 0.56 pts
  2. Serve +1: short return to your backhand side hit BH through the middle ×4; BH down the line rates higher · 0.33 pts
  3. Rally, shots 5–8: drive to your backhand side hit BH through the middle ×6; BH crosscourt rates higher · 0.26 pts
  4. Return +1: drive to your middle, you at net hit BH volley through the middle ×1; BH volley crosscourt rates higher · 0.24 pts

Iga Swiatek

5.7 points left on the table across 246 shots 2.33 per 100 shots

  1. Return +1: drive to your forehand side hit FH through the middle ×5; FH crosscourt rates higher · 0.32 pts
  2. Rally, shots 5–8: drive to your middle hit FH through the middle ×4; FH crosscourt rates higher · 0.28 pts
  3. Long rally, 9+: lob to your forehand side, you at net hit Smash through the middle ×1; Smash crosscourt rates higher · 0.23 pts
  4. Rally, shots 5–8: drive to your backhand side hit FH through the middle ×2; FH inside-in rates higher · 0.21 pts