Having spent months handicapping individual Senate races and the probability of each party controlling the chamber, Nate Silver of FiveThirtyEight is now giving odds on when we’ll know the results:

There’s a 25 or 30 percent chance of a big, sweeping win for Republicans. There’s a 10 or 15 percent chance the Democrats retain the Senate with surprising ease. And there’s a 60 percent chance that we’ll be sweating out the races on a state-by-state basis, possibly for weeks to come.

The “sweat” comes from probable runoffs in LA and GA (though Nate thinks the odds of David Perdue winning without a runoff have gone up a bit in the last few days), the tightening of the race in slow-counting Alaska (where contests decided by less than 5 percent of the vote–a 70% probability at present–generally aren’t resolved until at least a couple of days), and the high probability of one or two close races somewhere else going into “Recountland.” Add in the continuing possibility of Greg Orman winning in Kansas and then refusing to choose a party caucus until January, and the 60% overtime odds seem reasonable enough. That will be another variable everyone will be trying to calculate when the exit polls start leaking out late Tuesday afternoon or early evening.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.