To win an Indian election, a political party must win a majority of seats in the lower house of parliament, or Lok Sabha. Since there are 543 seats in the Lok Sabha, this majority would amount to at least 272 seats.

Narendra Modi, the Hindu nationalist Bharatiya Janata Party (BJP)’s candidate for prime minister, is the current frontrunner in the Indian elections and is widely believed to be the country’s next leader. The ultimate success of the “Modi wave” rippling through India, however, depends on this arithmetic equation within the Lok Sabha. “Most polls have shown Modi’s BJP winning the largest number of seats while falling short of the 272 needed for a majority when election results are announced May 16,” Bibhudatta Pradhan writes in Bloomberg.

To actually become the country’s next prime minister, Modi must band together with other political parties willing to offer him support so he can control the number of seats he needs to succeed. This is not unusual in Indian politics; the country has been ruled by a coalition government since 1996. Ellen Barry of the New York Times writes about the process of coalition-building:

During the 10 days after an Indian election, a flurry of secret negotiating takes place as regional heavyweights barter parliamentary seats in exchange for a package of concessions — benefits for their state or themselves, or senior positions for their allies. Under any circumstances, it is a bare-knuckled game replete with double-dealing and deceit.

Mr. Modi’s party has had particular difficulty in building coalitions. Its first taste of national power in 1996 ended after just 13 days when it failed to attract enough allies. Some in the BJP fear a similar fate this time around because major regional players have been hesitant to partner with Mr. Modi.

According to the New York Times, Modi’s success likely depends on winning the backing of at least one of three female leaders, each of whom is a monolith in her own right: Jayalalithaa Jayaram, the leader of the state of Tamil Nadu; Mamata Banerjee, the leader of West Bengal; and Mayawati, a former leader of Uttar Pradesh. “Each can offer Mr. Modi something he needs: a mandate strong enough to endorse sweeping change. Each has flirted with the idea of forming a ‘third front’ that excluded the BJP And each, if left unsatisfied, has the ability to extract her pound of flesh,” Barry writes.

Bloomberg’s visual data team has also outlined the major coalitions and the stakes they play in different states in this handy infographic.

So this week may be the last “official” week of voting, but given the process of coalition-building and later designating seats of power, it will probably be another month before India sees its new government — whatever that may look like.

This piece was originally published on May 5, 2014, on Link TV’s World News website.