Because the presidency is up for grabs, and this model is your best bet on who will win it.

It’s a simple rule in politics: You let the boss deliver good news. And when it’s bad? Leave that to the flacks.

Which is how Bernie Sanders ended up announcing his Iowa victory — at least, in the first voter preference — Thursday, sporting perhaps the biggest smile he’s ever reserved for the establishment media while marveling at the roomful of reporters. And it’s also how Joe Biden senior adviser Symone Sanders (who was press secretary for Bernie Sanders in 2016) was stuck answering questions about the expected front-runner’s Iowa stumble before Biden’s first event in New Hampshire two days earlier.

Symone (no relation to her former boss) gamely parried them, waving a coffee cup and channeling the type of agitation Bernie is well known for. She excoriated the Iowa Democrats for their sins: the faulty app that didn’t report results, the backup phone calls that went unanswered, the locked doors when volunteers tried to hand-deliver the results. No, they weren’t threatening to sue … but they were deeply concerned, she said. Yet for all of that, there was no arguing with the results when they (finally) did trickle in: Sanders had basically tied for first with Pete Buttigieg, while Biden had fallen to fourth place in the first caucus state.

It’s a dangerous time for Biden. Kyle Kondik, University of Virginia political scientist

Going forward, you can expect the spotlight to be on both Sanders and Biden. That’s the prognosis from “The Forecast,” OZY’s exclusive prediction model that breaks down polls, demographics, fundraising figures, historical trends, media coverage and more. Our projections are brought to you in partnership with the Washington-based Republican technology and data firm 0ptimus and its sister election results company, Decision Desk HQ (check out our methodology here).

Nationally, Biden remains the favorite to take the nomination, but that front-runner status is razor-thin. His chances of securing a majority of pledged delegates by the time of the Democratic National Convention dropped from 37 percent last week to 21 percent on Thursday. Right behind him is Sanders, who jumped from 13 percent to almost 20 percent after his strong Iowa performance. There remains a roughly 41 percent chance, according to our model, of a floor fight at the convention.

Our model expects the rest of the race to be a roller coaster. New Hampshire, at this moment, is a muddle with a whopping eight candidates claiming at least 5 percent of the vote. Sanders is projected to win New Hampshire with 24 percent of the vote, with Biden well behind at 16 percent and Buttigieg at 15 percent. “Some of the most recent New Hampshire polling is indicating that Buttigieg is getting something of a bounce and Biden is slipping,” says Kyle Kondik, managing editor of Larry Sabato’s Crystal Ball at the University of Virginia.

But the race remains “vexing,” Kondik admits. While pundits knew that the first two states could be problems for Biden, “it’s one thing to say that in advance; it’s another thing to have to live through it,” he adds. “It’s a dangerous time for Biden.”

Yet Biden is still ahead in Nevada, as our projections have him at 31 percent to Sanders’ 21 percent. If Biden could pair a Nevada win with a likely South Carolina victory, the former vice president may make back much of the ground he’s lost to Sanders going into Super Tuesday. Still, our model may be overestimating Biden’s chances because it hasn’t had enough time to adjust to the delay in the Iowa results.

“The model has not caught up to conventional wisdom, because the two biggest factors — the polling, which we’ll get more of in the next 72 hours, and the [latest fundraising reports] — aren’t in yet,” warns Scott Tranter, CEO of 0ptimus.

The one person who really needs to make a mark in New Hampshire? Buttigieg, whom “The Forecast” gives just a 4 percent chance of winning the nomination despite his Iowa success. “It’s a really good sign for Buttigieg that he is starting to surge in New Hampshire,” says 0ptimus data scientist Jakob Grimmius. “I think it’s now or never for him. He has to capitalize on the momentum from his Iowa victory with a good result in New Hampshire, or he could fall out of contention quickly.”

Given all that turbulence, the real favorite going forward actually isn’t a candidate at all: It’s chaos, with the high odds of a contested convention. Given what the nation just saw in Iowa, it would be a disastrously messy affair.

In fact, the biggest lesson from the Hawkeye State may not be about electoral math at all. Instead, expect a lot of candidates to follow the Buttigieg model of declaring victory quickly and confidently going forward, even if the actual facts behind those wins are still far from certain.