Not all primes are better than zooms. For instance, the 24-70L zoom is actually slightly sharper than the, yes, the member of the holy trinity, 35L prime, when stopped down. I've seen it myself and Bryan Carnathan noticed it as well. It depends on how high quality the zoom lens is. No sane person would say the 85 f/1.8 is sharper than the 70-200L II IS zoom lens at 85mm, at f/8. There are a lot of factors. Personally, for sports, I NEED the flexibility of the zooms. A missed shot is worse than a slightly less saturated shot, for example.