Nicholas Linthorne and David Everett from the University of Brunel, UK, have worked out the optimum angle for a footballer to launch a throw-in — it's 30 degrees to the horizontal, 15 degrees less than textbooks normally state. The two filmed a player throwing the ball at angles between 10 and 60 degrees and then used biomechanical software to measure velocity and angle in each case. Using the equations that describe the flight of a spherical object, they calculated the optimum launch angle to be 30 degrees. Thrown at this angle, the ball has the best chance to fly all the way to the penalty area, giving other players a great opportunity to score. And it goes even further if it's launched with a backspin at an even lower angle.

The same methods can be used for any other sport involving the throwing of a ball. Next, Linthorne will calculate the optimum angle at which to take a goal kick. To find out more, read their paper Release angle for attaining maximum distance in the soccer throw-in, or look at Nicholas Linthorne's homepage.