When the New York Yankees signed Miami Marlins slugger Giancarlo Stanton for more than three times the Rays entire payroll, I thought of two words. No, not some knee-jerk, obscene imperative, although I do dislike the Yankees. But “salary cap.” MLB needs one so that everybody plays by the same rules. Other professional sports do it. Sure, MLB has a luxury tax, but only luxuriating franchises pay it, the cost of doing business in competition with teams with far less resources.