“Cautionary tale” doesn’t do some sports bios justice. Ask Pete Rose. Or Denny McLain. The Detroit Tigers’ ace pitcher won 31 games in 1968 — a feat unmatched since — and seemed destined for a storybook career. There’s a story, anyway: a three-month suspension in 1970 for ties to the gambling underworld that meant the loss of income, his fastball and career. His pitches may have slowed down, but he didn’t, spending time at the baccarat tables and in prison, continuing a tale in which caution never got to first base.