The word handbook in a title is a promise of usefulness, and Old Grappler Handbook makes that promise twice over: the first word narrows the audience and the second sets the tone. This is material for people who intend to keep training, delivered by the same voice that wrote it rather than handed off to a stranger.
Our records carry no verified background beyond that, so the shelves do the rest of the describing. The catalogue lists the recording under sports and outdoors, health and wellbeing and personal development all at once, which is a telling combination: less a technique manual than an argument about how to keep doing a demanding thing as the years accumulate.