One of the beautiful things about professional sports in this era is the simple fact that there is so much visual documentation. Organized competitive sports are not a 20th-century invention, but to have the unbroken lineage we have of being able to see how the game developed is a wonder.
And we even have so much more than that. We have coaching clinics and all sorts of other exercises in which are showcased the fundamentals as well as the tricks of the trade. It’s part of the fraternity of the profession that players at the same position, even across rivalries, still share a bond as well as trade secrets.