In 2004, most pollsters failed because they did not factor in the complete UPA political formation.
For e.g. In Karnataka, a JDS-Congress alliance will sweep all 28 seats since they add up to 53% vote share. If they fight separately it maybe a different story.
In West Bengal, a TMC-Congress coalition will give the Left a bloody nose on one hand while reducing NDA tally on the other hand.
RJD-LJP-Congress alliance in Bihar can see UPA giving JDU-BJP alliance a run for their money.