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“What had long been off the list to experimenters as ‘real politics’ was now on the table,” Mr. Issenberg writes. “Mr. Carney was ready to test anything the academics could figure out how to randomize, from lawn signs to television ads.” They studied how far from planned political events you should send invitations. Their randomized decisions dictated what kinds of ads ran in different markets. They even helped set the governor’s campaign travel schedule.

The research results were useful to Mr. Perry’s 2010 re-election. Running Mr. Perry’s contested Republican primary against U.S. Sen. Kay Bailey Hutchison, Mr. Carney banished yard signs, obviously, and also “direct mail, robocalls, newspaper ads, and visits to editorial boards.” Mr. Perry thrashed Ms. Hutchison by 20 points. Mr. Carney also did away with regional campaign offices, built up the campaign’s virtual presence, and held a lot of cash in reserve to attack Bill White, the moderate Democrat and three-term Houston mayor, in the weeks just before the election. Result: Mr. Perry by almost 16 percent.

So why has Mr. Perry performed so poorly on the national stage? Because he is proving to be a lousy national candidate, is one reason. His poor showing also exposes the limits of a “Moneyball” approach to politics. Applying statistical rigor to campaign practices can help improve performance, but it cannot guarantee victories any more than endorsing sabermetrics made Billy Beane’s Oakland A’s a lock to win playoffs.

The “Moneyball” advantage also dissipates as the success of one team or campaign is copied by all the others. In a sense, American baseball clubs are all Moneyballers now. And when Mr. Obama’s historically well-funded re-election effort refuses to pay for supporters’ yard signs, we’ll know exactly whom to blame.

Jeremy Lott, editor of Real Clear Books, is writing a book about death.