Compare My Left Foot (1989), There Will Be Blood (2007) and Lincoln (2012), the three performances for which Day-Lewis won Best Actor. Notice how voice, posture and rhythm create distinct people.

He beats De Niro on our preference for transformation across sharply different dramatic worlds. Brando receives the influence tie-break above him. If disappearing into a role is your chief definition of greatness, Day-Lewis should be first; second reflects our criteria, not a smaller acting achievement.

Academy.

Photo: Jürgen Fauth (flickr user muckster) · CC BY-SA 3.0. Optimized; license retained.