Last edited 17oct16 by jgmalik@illinois.edu Find this document at http://new.math.uiuc.edu/math198/jgmalik

Soccer Free Kick Simulation

by Joaquin Gutierrez Malik

Abstract

The goal of my project is to create an interactive animation that simulates a free kick in soccer. I have created this animation using Vpython "blobby" figures.

This is a free kick:

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A free kick occurs in a soccer game when a player is fouled by an opponent. The team of the fouled player is awarded a "free kick" and gets the opportunity to play the ball from a standing start. The opponents are not allowed to come within 10m of the free kick taker until the ball is kicked. Often when the free kick is near to the goal, the opposing team will set up a "wall" of players, as you see here. This allows the keeper to focus his attention on a much smaller portion of the goal that he has to cover. However skilled players can put the ball over or around the wall to catch the keeper off guard, as you see here.

Here are a few more examples of free kicks in matches: Cristiano Ronaldo free kick, David Beckham free kick, Luis Suarez free kick, and Oscar free kick.

The Science of a Free Kick


The Magnus Effect

The Magnus Effect occurs when a ball is hit or kicked with a very large amount of spin. If the ball flies over a large enough distance, at a certain point, the velocity will begin to drop off and the trajectory of the ball will become dictated by the spin that was applied rather than its velocity. This causes a very sudden "hook" or "curve" motion by the ball. Highly skilled players are able to take advantage of this to confuse keepers during a free kick. The ball seems to be going out of bounds or to a completely different area, and then suddenly hooks into the goal, catching the keeper by surprise.

Here are two examples of this in action.

Paul Pogba's "Wonder Volley"

Roberto Carlos "The Impossible Goal"

My Project

Here are two animated gifs of the project in action (Click on the Image):
Proof of Concept: Player juggling a soccer ball

Final Simulation: Player taking a free kick

You can find links to my project documentation below:
Proposal
Narrative