The laws of physics are universal. They characterize a model that describes and predicts how things work within reasonably well defined limits. Classical physics describes and predicts how things work in our everyday environment. Football falls well into the limits of classical physics.
The laws of classical physics can be expressed in terms of a very limited set of laws, that, when put into mathematical form, yield a very limited set of equations.
 | Newton's laws of motion predicts how an object moves when acted on by a net force. |
| Newton's law of gravitation predicts the force objects exert on each other because they have mass. |
| Maxwell's equations predict all phenomena associated with electricity and magnetism. |
| The Lorentz force predicts the force objects exert on each other if they have charge. |
Because there are so many objects interacting in so many different ways, that it is very hard to keep track of all the interactions.
In football we encounter many situations where only a few interactions, maybe only one push or pull, are so much more important than all other interactions that we can understand how things work considering only the most important forces.