Polling: Baseball's Stat Star on Campaign '08

On May 6, expectations were high for Hillary Clinton. After all, the latest polls suggested the former First Lady had built up a 5-point cushion in Indiana and slashed Barack Obama's 20-point lead in North Carolina to 8. But over at FiveThirty Eight.com, an anonymous blogger (nom d'écran: "Poblano") wasn't convinced. Relying on demographic data from previous primaries and ignoring the usual mishmash of polls, the mysterious upstart projected that Clinton would win Indiana by 2 percent and lose North Carolina by 17—a far-less favorable outcome. When the results finally rolled in—1 in Indiana, 15 in North Carolina—Poblano had outperformed every established pollster. Clinton never recovered, but with the National Journal, the Guardian and the New York Post suddenly dissecting or demanding the secrets of his success, Poblano became an Internet sensation. "It was kind of amazing," he says.

It only gets better. For the man behind the blog, outpredicting the experts wasn't anything new—even if outpredicting political experts was. On May 30, Poblano finally revealed his offline name: Nate Silver. Doesn't ring a bell? Chances are you're not a baseball geek. Silver, 30, is already celebrated among ball fans for inventing something called PECOTA. Developed while the University of Chicago econ alum slogged through a post-collegiate consulting gig—"I'm used to not sleeping," he tells NEWSWEEK—PECOTA is now recognized as the most accurate system for forecasting how athletes and teams will perform in the future (down to the number of singles). In 2007, Silver's algorithm enraged at least half of Chicago when it said the White Sox—2005 champs—would post a 72–90 record. Turned out PECOTA was exactly right. For laypeople, the leap from the national pastime to national politics might seem like a stretch. But not for Silver (who posted his first political item on Daily Kos in October). "Baseball and politics are data-driven," he's written. "But a lot of the time, that data might be used badly. In baseball, that may mean looking at a statistic like batting average when things like on-base percentage and slugging percentage are far more correlated with winning ballgames. In politics, that might mean cherry-picking a certain polling result." In other words, different sport—same skill set.

From the start, Silver took pride in myth-busting the MSM, which has tended to reduce 2008's complex calculus—delegate distribution, demographic coalitions—into not-quite-true narratives. Obama has a problem with working-class whites? Actu-ally, he has a problem with Appalachian working-class whites—and not their cousins in Oregon and Wisconsin. And so on. The response was ecstatic, and FiveThirtyEight's daily traffic increased 5,000 percent between March and June. But the main attraction was always Silver's primary predictions. Taking a page from PECOTA—a comprehensive historical database, it projects future performance by matching current players to comparable predecessors—Poblano predicted the results in, say, Pittsburgh by measuring how Clinton and Obama did in demographically similar congressional districts earlier on (once set, their coalitions were remarkably stable). Silver's score wasn't perfect—he underestimated Clinton in Kentucky and South Dakota. But ultimately, he came within 20 delegates of the final split on Super Tuesday (out of nearly 1,700) and 2.5 percent, on average, in the other six post-March primaries. "Nate's work is innovative," says Mark Blumenthal of Pollster.com.

So who will win in November? Silver says Obama (full disclosure: he's a supporter). Predicting the Election Day outcome is not like predicting a primary; with no previous head-to-head results to mine, Silver is relying on Census data to balance out the polls. So far, Silver's system shows Obama and McCain splitting the popular vote 50.0 percent to 50.0 percent, with Obama winning the Electoral College 274.4 to 263.6. Today, McCain runs about 10 points better than Bush in parts of the Northeast—his strongest region, comparatively—but it's not enough to swing any states. The Arizonan's best chance for a flip? Michigan. Obama, on the other hand, currently swipes Colorado, New Mexico and Iowa from the GOP, and is within striking distance in Indiana, Missouri, Ohio, Virginia and even Alaska. And thanks to Nebraska, where electors are awarded by congressional district, Silver even suspects that McCain and Obama could, um, tie. "Right now, Obama's losing the state by 10 points, but that's 10 points better than Dems usually do," he says. "If Obama wins Colorado, Iowa and the city of Omaha, where he's popular, it would end up 269–269 and go to the House of Representatives. Crazier things could happen."

They could. And Silver will probably be the first to know.