RallyIQ

Olympics · F · Clay · 8 Aug 1992

Steffi Graf v Jennifer Capriati

91–95 in points · Jennifer Capriati won

Why it went the way it did

Jennifer Capriati won 3.1 more points than Steffi Graf relative to what the serve alone predicted. Steffi Graf's biggest leaks: slice shot selection −5.0, forehand execution −4.9, return execution −3.2.

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.

ShotSteffi GrafJennifer Capriati
DirSelExecTotalDirSelExecTotal
Serve 1st +0.1 −0.2 −0.7 −0.7 −0.2 −0.1 +1.4 +1.1
Serve 2nd ±0.0 −0.1 +0.5 +0.5 ±0.0 ±0.0 +0.1 +0.1
Return +0.8 −0.5 −3.2 −2.9 ±0.0 +0.2 −1.6 −1.4
Forehand +1.7 +4.3 −4.9 +1.2 +0.3 +1.8 −1.4 +0.6
Backhand ±0.0 +0.2 +0.6 +0.9 +0.5 −1.8 +4.2 +2.9
Slice +3.6 −5.0 −0.1 −1.5 −0.2 −1.4 −1.4 −3.0
Net +0.5 +0.5 −1.6 −0.7 +0.3 −0.2 −0.3 −0.2
Touch +0.2 −0.1 +0.6 +0.7 ±0.0 −0.2 +0.6 +0.4
All shots +6.8−0.8 −8.6−2.6 +0.8−1.8 +1.6+0.5

Set by set

SetSteffi GrafJennifer CapriatiNet, Steffi
1−3.1−6.0 +2.9
2+0.2+4.1 −3.9
3+0.3+2.4 −2.1

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.

Steffi Graf serving

SetWideBodyT
1 45% 71% 21% 45% 34% 61%
2 46% 64% 21% 80% 33% 50%
3 48% 64% 17% 40% 34% 60%

Set to set +0.12 per 100 first serves in sets 2+

Within sets +0.38 per 100 first serves, every two to three service games

Jennifer Capriati serving

SetWideBodyT
1 44% 50% 22% 67% 33% 67%
2 42% 64% 31% 75% 27% 100%
3 37% 70% 26% 43% 37% 80%

Set to set +1.71 per 100 first serves in sets 2+

Within sets −0.32 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.

Steffi Graf

6.8 points left on the table across 460 shots 1.47 per 100 shots

  1. Rally, shots 5–8: drive to your backhand side hit BH slice down the line ×8; BH slice crosscourt rates higher · 0.70 pts
  2. Long rally, 9+: drive to your backhand side hit BH slice down the line ×7; BH slice crosscourt rates higher · 0.33 pts
  3. Serve +1: deep return to your backhand side hit BH slice down the line ×3; BH slice through the middle rates higher · 0.31 pts
  4. Long rally, 9+: drive to your backhand side hit BH slice through the middle ×5; BH slice crosscourt rates higher · 0.26 pts

Jennifer Capriati

11.2 points left on the table across 473 shots 2.37 per 100 shots

  1. Rally, shots 5–8: slice to your backhand side hit BH crosscourt ×46; BH down the line rates higher · 1.26 pts
  2. Long rally, 9+: slice to your backhand side hit BH crosscourt ×35; BH down the line rates higher · 0.94 pts
  3. Return +1: slice to your backhand side hit BH crosscourt ×17; BH down the line rates higher · 0.62 pts
  4. Return of a 1st serve, wide, deuce court hit FH down the line ×8; FH crosscourt rates higher · 0.55 pts