Des Moines, Iowa—Here is a list of the winners of the Iowa Democratic Caucuses over the past half-century: 1972: Uncommitted; 1976: Uncommitted; 1980: Jimmy Carter; 1984: Walter Mondale; 1988: Richard Gephardt; 1992: Tom Harkin; 1996: Bill Clinton; 2000: Al Gore; 2004: John Kerry; 2008: Barack Obama; 2012: Barack Obama; 2016: Hillary Clinton.

That’s not a terrible track record. Eight winners went on to be the nominees of the party. But only three Iowa winners went on to assume the presidency after the November election—and two of them (Bill Clinton and Obama) were incumbents who faced no meaningful caucus competition. So, in an open contest, like the one that will be held tonight, just one winner of the Iowa Democratic caucuses (Obama) has gone on to be elected president. In contrast, seven winners of the Iowa caucuses at the start of the year did not finish the year as winners. Five caucus winners lost to the Republican nominee. Two winners failed to secure the Democratic nomination, and in two early contests, the formal “winner” of the caucuses was no one at all.

This is a caution for all of us tonight as we look to identify a winner. Someone will finish first. And it is possible that there could be a big winner. Abbey Boyd, a graduate student in Ames who knows a good deal about caucuses and caucusing, says, “Sometimes, if a candidate is really doing well, everyone just decides they want to be with the winner.”

But, tonight, it is also possible that different measures might produce several winners. As The Des Moines Register, a paper that provides intensive and insightful coverage of the caucuses explained in December:

For decades, the winner of Iowa’s caucuses has been decided by a complicated system of state delegate equivalents, which operates kind of like the Electoral College. Unlike in the November presidential vote, though, Iowa’s tally of popular support was never released. But in 2020, the Iowa Democratic Party will publish two raw vote totals and the delegate numbers from caucus night. So one candidate could win one or both of the delegate counts but lose the popular vote. That would open a new layer of complexity as media report the results, campaigns spin them and voters in later states try to make sense of them—all in a year when the stakes have never been higher for Iowa to show it deserves to remain the first-in-the-nation presidential voting state.

The headline of that analysis was: “Could multiple candidates ‘win’ the Democratic caucuses? New rules make it possible.”

The Associated Press will try to sort things out by declaring a winner based on the number of state delegate equivalents awarded to the candidates. “AP will base its race call on state delegate equivalents because delegates are the metric used to decide the eventual winner of the Democratic presidential nomination,” explains the wire service. “The Iowa Democratic Party will also provide two additional results for the first time this year: how much support candidates had from voters at the beginning of the caucuses and how much support they had at the end after voters backing low-performing candidates are allowed to switch their support. The latter total is then used to determine state delegate equivalents.”

But wait! Finishing first is never the only measure of a winner in Iowa. Iowa Democrats like congressional candidate J.D. Scholten, who is expected to take on Republican Representative Steve King this fall, refer to the “tickets out of Iowa” that candidates can get—not just with a first-place finish but with strong second, third and even fourth-place finishes.

For instance, Vermont Senator Bernie Sanders could finish first tonight, as many polls suggest will be the case. But if Massachusetts Senator Elizabeth Warren finishes second, after a period in which her poll numbers have slid some, she could get a big boost. That’s a possibility, as Warren gets high marks for her organization in Iowa. In addition, Warren has worked hard to make herself an appealing “second choice” for caucus-goers whose first-choice candidates fall short of the threshold—15 percent of the people in the room—for getting votes counted toward caucus delegates.

A second-place finish would also boost former South Bend, Indiana, mayor Pete Buttigieg. And it wouldn’t be so bad for the front runner in most national polls, former vice president Joe Biden. But if Biden or Buttigieg were to finish behind Minnesota Senator Amy Klobuchar or businessman Andrew Yang, who have mounted serious bids in Iowa, their tickets might not get them very far.

It all starts at 7 tonight, when the caucuses convene in the state’s 1,679 precincts—and at 60 “satellite” caucuses across the state, 24 out-of-state “satellite” caucuses and three international gatherings. Because a record high turnout is expected—Iowa Democrats are preparing for a turnout in excess of the 240,000 seen in 2008—the meetings and the tabulation of results could run long. And that won’t be the end of it.

The process of choosing the state’s 41 pledged delegates to this summer’s Democratic National Convention only begins this evening. The delegates chosen tonight will be precinct delegates to county conventions in March, where delegates are then chosen for congressional district conventions in April, where delegates are chosen for the state convention in June. That’s where the actual delegates to the convention in Milwaukee will be selected.

The twists and turns of the race for the nomination—with candidates dropping in and dropping out—invariably mean that the national delegates named at the state convention are apportioned differently from the results on caucus night. So, if you really want to know the winner, check back in June.