A business-like, often impersonal comparison of the two heavyweight champs warms up after several chapters, and the back and forth profiling of Ali versus Sonny Liston grows more compelling. The diverse interpretations from other fighters ( Sugar Ray Robinson, Rocky Marciano) do as much to characterize the era of boxing from the 1950s through the 70s as they provide interesting (and oftentimes clashing) opinions about the behavior of both men-- in and outside the ring. Ali's various controversies with the US government regarding Vietnam are no less shocking than Liston's sordid ties to organized crime, or his outbursts of lawlessness. And Liston's premature death is troubling, a still unsolved mystery. The book also benefits from the insights (and profane remarks) from great journalists and trainers alike.