Also a football
reference of sorts.
In his 1979 autobiography "They Call Me Assassin", Raiders safety Jack Tatum explains in some detail his methods, which many described as "dirty". One of his most common techniques, he called The Hook.
As he describes: "The Hook is simply flexing your biceps and trying to catch the receiver's head in the joint between the forearm and the upper arm. It's like hitting with the biceps by using a headlock type of action. The purpose of the Hook was to strip the receiver of the ball, his helmet, his head, and his courage."
This was one of many reasons why Tatum was universally disliked, except by Raiders fans. Such a "technique" is now illegal in the NFL (and just about anywhere else).
And by the way, the book is a chilling look into football and is a good read. I found it at a garage sale for 50 cents a few weeks ago.