Monday’s Iowa caucuses may seem like a straightforward affair, in which presidential candidates who win the most support statewide are awarded the most nominating delegates at their parties’ national conventions. But especially on the Democratic side, the math is more complicated, and the state’s registration rules can help candidates who may be relying on first-time voters.

On the Republican side, the convention delegates are awarded proportionally based on the overall statewide totals from the caucuses. But on the Democratic side, delegates are awarded not as a percentage of the state’s total support, but instead are “awarded proportionately, based on statewide and congressional district voting,” according to the Chicago Tribune.

That structure could hurt candidates whose supporters are concentrated rather than spread evenly throughout the state. Relying on backing from younger voters in college towns, Bernie Sanders may be disadvantaged by the rules: As MSNBC points out, a recent Des Moines Register poll showed that “more than a quarter — 27 percent — of Sanders supporters come from just three counties of Iowa’s 99 [and] those three counties award only 12 percent of the total 1401 delegates at stake statewide.”

In other words, the news outlet wrote, in the same way that the Electoral College gives more weight to a vote from Ohio than from Vermont, “the caucus process makes it so extra supporters in a heavily Sanders precinct are worth less than if they were in a battleground precinct” — meaning “even if Sanders racks up delegates in population centers, Clinton can beat him by winning dozens of smaller counties.”

As for who will vote, the New York Times reports there has not been as big a surge in new registrations as there was in 2008, another factor that may end up hurting Sanders, who, polls show, is relying on new voters. Sanders’ campaign is also hoping to turn out teens who will be old enough to vote by Election Day. However, early numbers may provide a misleading picture, because Iowa permits first-time voters to register on the night of the caucus, and allows them to change their party registration to vote in a particular caucus. Recent polls have shown Sanders leads Hillary Clinton among independent voters, while an average of polls from RealClearPolitics shows Clinton with a slight lead in Iowa overall.

As BuzzFeed points out, if the results are close — as polls suggest — “the frontrunners get virtually the same number of delegates anyway, making it all slightly pointless.” But the winner can count on a boost in terms of perception, and may be able to carry forward “momentum” to the next electoral contests.