Israeli elections are, in a word, complicated—and Tuesday's will feature an embattled incumbent, money pouring in on both sides, and a number of unpredictable dynamics. Israel’s parliamentary system rewards whichever party, or party leader, would be most capable of forming a sustainable ruling coalition—a process that creates a volatile mix of legislative agendas, political ambitions, expediency, and personal relationships. A recent example of this process at work was Tzipi Livni’s “win” in 2009, when her party garnered more seats than Benjamin Netanyahu’s, but she nevertheless lost the premiership to him when he managed to form a majority coalition. This means that the election drama will go on well after the ballots are counted, when party leaders negotiate with the president to choose a prime minister.

As of last week, polls showed the main opposition party, Isaac Herzog and Tzipi Livni’s center-left Zionist Union, with a comfortable lead over Prime Minister Benjamin Netanyahu’s right-leaning Likud Party. Given the reality of coalition politics, though, the race for the premiership is still wide open. Natan Sachs from the Brookings Institution has broken down various potential outcomes. Meanwhile, here are just a few of the wild cards that could determine the next prime minister of Israel.

Moshe Kahlon

Moshe Kahlon is not a household name in the United States, but as a former minister of communications, Kahlon has as his claim to fame a successful reform of the cell-phone industry credited with reducing service rates in the country by 90 percent—making the then-minister an instant political superhero and boosting his popularity above that of Netanyahu. In an election where socio-economic issues have dominated the conversation, the importance of this kind of measurable social reform cannot be overstated.

When Kahlon announced that he would be entering these elections, some centrist Israelis viewed him as a savior. Polls from back in December already projected that Kahlon—who had yet to even form a party—would come in with the fourth-highest number of seats, and his star hasn’t diminished much since then. Kahlon’s party, Kulanu, is expected to gain enough Knesset seats to be a significant member of any prime minister’s coalition, and Kahlon has made a point of not committing himself to either the right or the left.

Joint Arab List

For the first time in Israeli history, the country’s Arab parties have decided to unite and run as a single group for Tuesday’s elections. The parties on the list range from Hadash, a communist party, to Balad, an Arab-nationalist party that rejects both Zionism and a two-state solution. (Instead, it advocates a binational state that would, by virtue of demographics, not be Jewish.) The parties originally united for the sake of survival; a new law, which some see as designed to squeeze out smaller parties and disenfranchise Arab Israelis, raised the threshold of votes needed to get any seats in parliament. If the intent of the law was to reduce Arab Israelis’ voting power, it has definitively backfired—Arab Israeli voter turnout is expected to increase this election, and the joint Arab list is consistently ranking as one of the top parties in the polls.

While the Arab parties will certainly have more representation in the Knesset after this election, it is less certain how the unified list will affect who gets the premiership. Ayman Odeh, the chairman of the joint list, has declared, “The ultimate goal is to get out Netanyahu. That is the most important thing.” Odeh’s intentions, combined with his electoral power, would seem to mean that Herzog’s Zionist Union stands a better chance than not of gaining the premiership. However, the picture is complicated by the fact that, according to multiple reports, the Arab parties have no intention of joining a hypothetical coalition under Herzog. Given the possibility of a national unity government between Herzog and Netanyahu, the Arab list has one other enticing option before it: to be the leader of the opposition. This would provide the Arab parties with an unprecedented opportunity to promote their legislative agenda within the Knesset and on the international stage.

The Unpredictable Israeli Voter

Rare is the election in Israel without a significant portion of the voting public still undecided in the closing days of the campaign. In 2009, around 20 percent of voters were undecided on the eve of the election. In 2013, that number was 31 percent. This time around, only 14 percent of voters were still undecided in the last week before the election—a result, in part, of what Al-Monitor’s Mazal Mualem described as the “shifting sands” phenomenon. A large portion of the electorate doesn't identify with any particular party, and given the plethora of options, has been prone to switching allegiances throughout the campaign.

It’s not just the voters that are unpredictable—the polls can’t necessarily be trusted either. “Israeli polls are inherently unreliable,” Gershom Gorenberg wrote in Haaretz. One need look no further than the 2013 election for evidence. On the eve of that election, Yair Lapid’s center-left Yesh Atid party defied projections of a modest win to become the second-largest party in the Knesset. Whereas many believed the 2013 elections would lead to the installation of a fiercely right-wing government, Lapid’s surprise success reshaped the calculus and temperament of the ruling coalition, nudging it in a more moderate direction. With Tuesday’s election already outshining the last in novelty factors, surprise may once again be the name of the game.