This isn't a book I've ever heard discussed--it's probably obscure now--but both my high school library and local public library did have a copy, and the title and caption on the cover (which shows a picture of Cousy looking very troubled, and says "Mr. Basketball thought winning was the only thing, until [something] on the edge of moral and physical collapse." I was intrigued, and although probably ten years passed of me seeing the book on and off before I decided to read it, I eventually did.
A number of NBA legends I know of were known to be absolutely ruthless, focused, and obsessed with winning their games--Michael Jordan was hardly the only one of them, just the most notorious and popular. Cousy was probably the first with this "Killer Instinct," and the book is about how it affected him as a player, coach and person.
I certainly admit that I haven't read many biographies of NBA players (in fact, Cousy's is probably the only one), but of these players with the Killer Instinct--these players who take winning so seriously that they will work up feelings of rage to motivate themselves and treat opposing players as enemies to be destroyed--Cousy is the only one I know of who wasn't corrupted by being hypercompetitive. As a player, Cousy had an extreme fear of failure (apparently the cause of his hypercompetitiveness, not the effect of it); it led to nightmares, sleepwalking, intense emotional reactions to losing, and eventual visits to a psychiatrist (who diagnosed him with panic attacks). After his playing career ends, he becomes a coach at both the college and NBA level, and his drive and intensity tempt him to cheat by making promises to his college recruits that he can't keep. He resists, but eventually tires of it and the strain his hypercompetitiveness puts on his health, and leaves coaching. For this, Cousy is one of the very few basketball players I know anything about that I respect. And did I mention that he strongly opposed racism in basketball in the 1960s?