People are trying to dumb down science so it can be "understandable", often by using sport-analogies. It doesn't help that these dumbed down sport-analogies often feature American sports seldom found in other countries.
The net effect is that if I was in need of a explanation, I'm still confused and all of a sudden annoyed at footballers too.
I think it is spinning ball 100% of the time.
> Feynman was a truly great teacher. He prided himself on being able to devise ways to explain even the most profound ideas to beginning students. Once, I said to him, "Dick, explain to me, so that I can understand it, why spin one-half particles obey Fermi-Dirac statistics." Sizing up his audience perfectly, Feynman said, "I'll prepare a freshman lecture on it." But he came back a few days later to say, "I couldn't do it. I couldn't reduce it to the freshman level. That means we don't really understand it."
If Feynman couldn't do it, perhaps it's okay to give a pass on how spin is described in this article?
Basically you don't need analogy at all.
Spin is inherent property of a particle like mass, charge, etc. It's quantum like charge. If lagrangian of interaction includes particle's spin, spin effects will be noticeable in scattering and everywhere.
Analogy is only needed to not mix spin with angular momentum.
Funny how in media spin is left and right, but in science spin is always "up" or "down". :-)
This analogy has quite a lot of problems which arguably can confuse more than explain.
First thing my physics professor said in uni was "forget everything you've learned in school". This is applicable to spinning balls.
Article doesn't even try to describe what this $2 C_{2 u} − C_{2 d}$ coupling is all about.
If you're trying to follow High Energy Physics, your best choice is to follow abstracts in ArXiV (which in turn requires _some_ knowledge and education :-(.