Since the indie revolution of the early ’90s, the Academy’s best picture nominees have come to represent a fairly wide spectrum of productions in terms of scope and style. But if you look back at all the winners since 2000, the connective tissue is a nomination in the two other key filmmaking categories: directing and writing. Fourteen of those 15 winning films also vied in those categories (“Argo” is the one exception, with director Ben Affleck left off the helmer ballot), and eight of them scored the Academy’s trifecta. Given this barometer, a movie like “The Martian,” without a directing stake in the game, or “The Revenant,” sans a writer nomination, would appear to be at a disadvantage. But momentum can also be a factor, and “The Revenant” is gaining steam.