Larry Merchant, the venerable sportswriter and TV commentator recently observed, at the age of 92, that “it’s easy getting into your 80s but hard to get out of them.” That wisdom applies to two men who dominated boxing for a half-century and shaped the business as we know it today. Don King will turn 92 on 20 August. Bob Arum will be 92 on 8 December. Muhammad Ali’s longtime physician Ferdie Pacheco once suggested: “Think of Don King as a sledgehammer and Bob Arum as a stiletto.” British promoter Mickey Duff remarked: “One’s Black and one’s white. That’s the only...