For the last two-decades Tamil Nadu has swung back and forth between current Chief Minister J Jayalalithaa and Dravida Munnetra Kazhagam chief M Karunanidhi. And if the exit poll data from Monday's elections are anything to go by, 2016 will be no different. Despite expectations that Amma will return to power, four out of five major polls predicted a victory for the DMK. TimesNow-CVoter's poll, however, turned out to be a complete outlier, forecasting a comfortable win for Jayalalithaa.

This election has been unusual in Tamil Nadu. It came right after the devastating Chennai floods in December 2015 and not long after Jayalalithaa's acquittal by the Karnataka High Court in a corruption case. Yet the prevailing feeling suggested that this was an issue-less election, with only prohibition becoming a cause towards the end. Since every major political grouping has anyhow endorsed a ban on liquor, even that has not been a strong enough plank for any party to separate from the pack.

What made the election interesting, however, was the presence of multiple groupings being the Dravidian majors. Beyond the All India Anna Dravida Munnetra Kazhagam and the DMK, contesting along with the Congress, this election also featured a broad coalition with Desiya Morpokku Dravida Kazhagam head Captain Vijayakanth as its chief ministerial candidate. In addition, there was also the caste-based Pattali Makal Katchi as well as the Bharatiya Janata Party, hoping to expand into the South.

This multi-cornered contest might also have made it hard for pollsters to provide accurate predictions, since it would be hard to convert sampled vote shares into seat numbers. This might explain the huge discrepancy in CVoter's data, which brings down the average of the polls to numbers that suggest a hung assembly.

For most of the campaign, conventional wisdom suggested Jayalalithaa might be in place to retain power because of a lack of anti-incumbency. While it seemed like the DMK might have been gaining later by harping on the inaccessibility of Jayalalithaa, few predicted – prior to the elections – that the AIADMK would lose power.

Tuesday's exit poll data has upended this wisdom, though CVoter has given observers enough reasons to doubt the predictions. The vote shifts suggested by the polls giving DMK a victory also seem somewhat incredulous, though Tamil Nadu does have a history of decisive wins.