RallyIQ

US Open · F · Hard · 10 Sep 1988

Steffi Graf v Gabriela Sabatini

80–64 in points · Steffi Graf won

Why it went the way it did

Gabriela Sabatini won 2.5 more points than Steffi Graf relative to what the serve alone predicted. Steffi Graf's biggest leaks: forehand execution −5.6, slice shot selection −4.2, serve 1st execution −1.1.

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 GrafGabriela Sabatini
DirSelExecTotalDirSelExecTotal
Serve 1st +0.6 −0.2 −1.1 −0.6 +0.4 ±0.0 −0.2 +0.2
Serve 2nd +0.2 −0.1 +1.4 +1.5 ±0.0 −0.1 +0.7 +0.7
Return +0.2 −0.2 −0.1 −0.1 −0.4 −0.1 +1.2 +0.7
Forehand −0.1 +2.3 −5.6 −3.3 −0.5 +0.5 −0.4 −0.4
Backhand −0.1 −0.1 +0.2 ±0.0 −0.3 +0.5 −3.2 −2.9
Slice +2.4 −4.2 −0.2 −2.1 +0.1 −1.9 +0.5 −1.3
Net −0.1 +0.1 ±0.0 ±0.0 +0.2 ±0.0 −0.2 ±0.0
Touch +0.1 −0.4 −0.3 −0.6 ±0.0 −0.2 +0.5 +0.3
All shots +3.2−2.7 −5.7−5.3 −0.4−1.3 −1.1−2.8

Set by set

SetSteffi GrafGabriela SabatiniNet, Steffi
1+0.1−0.9 +0.9
2−3.8+1.1 −4.9
3−1.6−3.0 +1.4

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.

Steffi Graf serving

SetWideBodyT
1 81% 57% – 19% 80%
2 77% 45% 4% 100% 19% 40%
3 79% 64% – 21% 67%

Within sets +0.50 per 100 first serves, every two to three service games

Gabriela Sabatini serving

SetWideBodyT
1 20% 50% – 80% 63%
2 39% 55% 4% 100% 57% 69%
3 46% 50% – 54% 57%

Within sets −1.51 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.

Steffi Graf

8.4 points left on the table across 344 shots 2.43 per 100 shots

  1. Long rally, 9+: drive to your middle hit FH through the middle ×7; FH down the line rates higher · 0.49 pts
  2. Rally, shots 5–8: drive to your backhand side hit BH slice through the middle ×8; BH slice crosscourt rates higher · 0.48 pts
  3. Long rally, 9+: drive to your backhand side hit BH slice through the middle ×8; BH slice crosscourt rates higher · 0.42 pts
  4. Return of a 1st serve, wide, ad court hit BH slice down the line ×2; BH slice crosscourt rates higher · 0.35 pts

Gabriela Sabatini

10.9 points left on the table across 345 shots 3.15 per 100 shots

  1. Rally, shots 5–8: slice to your backhand side hit BH crosscourt ×26; BH down the line rates higher · 0.71 pts
  2. Return of a 2nd serve, wide, deuce court hit FH through the middle ×6; FH inside-out rates higher · 0.68 pts
  3. Long rally, 9+: slice to your backhand side hit BH through the middle ×8; BH down the line rates higher · 0.66 pts
  4. Return of a 2nd serve, wide, deuce court hit FH down the line ×5; FH inside-out rates higher · 0.50 pts