SPORTS · PENALTIES

PENALTY SHOOTOUT

Eleven metres, about half a second. Real ball flight, a keeper who has to guess.

YOU0

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KICK 1 OF 5

WHY IT'S A GUESS

0.4–0.5 s: for a 90–105 km/h kick to reach the line from 11 m.
~0.2 s: just to react to what you see — before any movement.
~0.85 s: for a keeper to get a hand to a top corner from the middle (estimate).
93.7%: of keepers dived in Bar-Eli's 286 penalties — yet staying in the middle saved the most (33% against 13–14%).
~3 in 4: shootout kicks are scored at major tournaments (Jordet et al., 2007).

So the keeper must commit before the ball is struck. Diving is the action bias: a goal conceded while standing still feels worse than one conceded diving.

where this comes from

Real: the goal, the mark and the ball are the Laws of the Game; the flight is integrated from gravity, quadratic drag (Cd ≈ 0.25, above the drag crisis) and Magnus lift from spin; the keepers' and kickers' choices are Bar-Eli's counts. Simplified: how long a keeper needs to reach a spot is a smooth estimate, not a measured player; the figures are stylised; a kick's spread and the 70% "tell" in the hips are chosen, not measured; the parry and the net are simple physics.

Laws of the Game. IFAB, Law 1 and Law 2: goal 7.32 × 2.44 m, penalty mark 11 m, ball 68–70 cm around and 410–450 g.
Ball flight. Goff, J. E. & Carré, M. J. (2009). Trajectory analysis of a soccer ball. American Journal of Physics 77, 1020 — drag near 0.25 above the drag crisis, lift rising with the spin parameter.
Drag crisis. Asai, T., Seo, K., Kobayashi, O. & Sakashita, R. (2007). Fundamental aerodynamics of the soccer ball. Sports Engineering 10, 101–109.
Keepers dive. Bar-Eli, M., Azar, O. H., Ritov, I., Keidar-Levin, Y. & Schein, G. (2007). Action bias among elite soccer goalkeepers: the case of penalty kicks. Journal of Economic Psychology 28, 606–621. 286 penalties: keepers dived 93.7% of the time, yet stayed-in-the-centre was the best-saving choice.
Shootouts. Jordet, G., Hartman, E., Visscher, C. & Lemmink, K. (2007). Kicks from the penalty mark in soccer: the roles of stress, skill, and fatigue for kick outcomes. Journal of Sports Sciences 25, 121–129 — about three kicks in four scored in major-tournament shootouts.
Reaction. Simple visual reaction time in healthy adults is about 0.2 s — see /reaction on this site for your own.

Tap the goal to aim. Set the pace and the curve, then shoot.

PACE 94 km/hCURVE none