Super Tuesday, the day roughly one-third of the Democrat Party’s pledged delegates are up for grabs, will give voters a better idea of where the Democrat race is headed, but the party’s 15 percent threshold requirement means it is not a winner-take-all kind of race, which could further extend the contentious primary and increase the chance of a contested convention — something some Sen. Bernie Sanders (I-VT) supporters fear most.

Voters in 14 states — Alabama, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont, and Virginia — will head to the polls on Tuesday, where about one-third of the Democrat Party’s pledged delegates, 1,357, will be available for the remaining Democrat presidential hopefuls. Sanders, the Democrat frontrunner, is leading in Super Tuesday state polls and hopes to expand his delegate lead significantly, particularly by winning big in delegate-rich states such as California (where 415 delegates are available) and Texas (where 228 are up for grabs).

Joe Biden (D), who is coming hot off a massive victory in South Carolina, is hoping to ride on that momentum and catch up to Sanders by raking in delegates on Tuesday — something he will be able to do, even if he comes out as the “loser” in some of the states. That is all thanks to the Democrats’ 15 percent threshold. Under the rules, a candidate who reaches the percentage or greater will be awarded delegates, even if he or she did not technically “win” the primary.

However, it breaks down even further, as there are two groups. Delegates are awarded proportionately at both the statewide level and district-level, but, again, only for those who reach the magic percentage of 15 percent.

The method of allocating delegates essentially makes it more difficult for candidates to pocket mass delegates in each state, particularly as multiple candidates remain in the race, further splitting the results.

“It’s very hard for winners to wrap up delegates,” Brookings Institution senior fellow Elaine C. Kamarck told the New York Times.

“The system tends to reward not losers, but second-place finishers, and that keeps the race going longer,” she added.

That process could lead to what many Sanders supporters fear: A brokered convention or a scenario where no candidate enters the convention with a clear majority of pledged delegates — 1,991. In that event, the vote would go to a second ballot, where superdelegates could then, hypothetically, back someone other than the candidate with the most delegates. Some have already signaled the possibility of leaving Sanders in the dust, even if he is leading in delegate totals.

All of this will play out on Tuesday as Sanders tries to expand his lead, Biden attempts to reestablish himself as the Sanders alternative, Mike Bloomberg (D) tries to assert himself as a viable contender, and Sen. Elizabeth Warren (D-MA) angles to breathe life into her flailing campaign.