RallyIQ

Miami Masters · R32 · Hard · 27 Mar 2016

Viktor Troicki v David Goffin

29–56 in points · David Goffin won

Why it went the way it did

David Goffin won 13.4 more points than Viktor Troicki relative to what the serve alone predicted. Viktor Troicki's biggest leaks: forehand execution −4.5, slice shot selection −1.2, forehand direction choices −0.9.

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.

ShotViktor TroickiDavid Goffin
DirSelExecTotalDirSelExecTotal
Serve 1st +0.1 ±0.0 ±0.0 ±0.0 ±0.0 −0.1 −1.2 −1.2
Serve 2nd ±0.0 ±0.0 +0.2 +0.2 ±0.0 ±0.0 +0.8 +0.7
Return +0.1 +0.2 +0.1 +0.5 +0.1 +0.5 +2.0 +2.5
Forehand −0.9 +0.9 −4.5 −4.5 −0.7 +1.5 +4.2 +5.0
Backhand +0.1 −0.3 −0.8 −1.0 −0.4 −0.4 −1.0 −1.8
Slice ±0.0 −1.2 −0.8 −2.0 +0.1 −0.4 −0.3 −0.6
Net −0.3 +0.2 −0.2 −0.3 +0.2 +0.6 +0.8 +1.7
Touch −0.1 −0.4 +0.2 −0.3 ±0.0 −0.1 −0.2 −0.3
All shots −0.9−0.7 −5.7−7.3 −0.7+1.5 +5.2+6.0

Set by set

SetViktor TroickiDavid GoffinNet, Viktor
1−5.8+2.7 −8.5
2−1.6+3.3 −4.9

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.

Viktor Troicki serving

SetWideBodyT
1 32% 43% 9% 0% 59% 38%
2 45% 44% 5% 100% 50% 40%

Within sets +0.51 per 100 first serves, every two to three service games

David Goffin serving

SetWideBodyT
1 20% 100% 20% 67% 60% 78%
2 43% 67% 4% 0% 54% 73%

Within sets +0.61 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.

Viktor Troicki

5.6 points left on the table across 207 shots 2.72 per 100 shots

  1. Rally, shots 5–8: drive to your middle hit FH through the middle ×9; FH crosscourt rates higher · 0.51 pts
  2. Rally, shots 5–8: drive to your forehand side hit FH through the middle ×8; FH crosscourt rates higher · 0.41 pts
  3. Rally, shots 5–8: drive to your forehand side, you at net hit FH volley through the middle ×1; FH volley crosscourt rates higher · 0.28 pts
  4. Return of a 2nd serve, T, ad court hit FH through the middle ×3; FH inside-out rates higher · 0.28 pts

David Goffin

4.8 points left on the table across 198 shots 2.45 per 100 shots

  1. Rally, shots 5–8: drive to your middle hit FH through the middle ×8; FH crosscourt rates higher · 0.46 pts
  2. Serve +1: mid-depth return to your middle hit FH through the middle ×5; FH crosscourt rates higher · 0.43 pts
  3. Rally, shots 5–8: drive to your backhand side hit BH through the middle ×10; BH crosscourt rates higher · 0.39 pts
  4. Long rally, 9+: drive to your backhand side hit BH through the middle ×5; BH crosscourt rates higher · 0.21 pts