Although size matters in many realms, not always in baseball. "The statistical relationship over the last 25 years between payroll and win percentage at the team level is .22," said Zimbalist, co-author with fellow Smith professor Benjamin Baumer of "The Sabermetric Revolution," which examines the statistics-laden model of analyzing and acquiring players that was pioneered by Bill James and popularized by "Moneyball."
"That means that 22 percent of the variation in win percentage is explained by the different payrolls teams have, and, of course, that 78 percent is explained by other factors," Zimbalist said. Those intangibles include injuries, team chemistry, drafts and player development, trades, luck, or maybe even an umpire's single call.
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That also means, alas, that "buying a championship," the refrain Red Sox fans love to throw at their Yankees counterparts, isn't possible in and of itself. "You can't buy love, and you can't buy victories," Zimbalist said.
Nonetheless, you can lavish big bucks on some awfully good players, a tactic for which both franchises are famous—or infamous, depending on your allegiance. The ROI on some of those acquisitions are legend, dating back to Boston's sale of Babe Ruth to New York in 1919 for $100,000.