Can BJP replace Congress as apparent beneficiary of simultaneous elections?

BJP has won only 4 of the 35 simultaneous polls in the past three decades

Do incumbents gain when simultaneous elections are held? This is a question bothering political parties, psephologists and political pundits ever since the mooting of the idea of simultaneous polls for both the Lok Sabha and the state Assemblies. 

A quick analysis of 35 simultaneous Assembly polls held during eight general elections between 1989 and 2014 provides no clear trend. Incumbents do not necessarily hold an advantage. On the contrary, not being an incumbent might be an advantage.

The analysis looked at the results of Assembly polls held at around the same time the general elections were held. The purpose of