From 1991 through 2011 the winner came from the final pairing 19 out of 21 times, exceptions being Johnson in '07 and Schwartzel in '11.
Zach was 2 shots back of the lead and tied for 4th place while Schwartzel was 4 back and tied for second.
If history repeats itself the winner will most likely be Mickelson or Hanson, and even if someone as far back as 4 shots (like Schwartzel in '11) prevails it narrows the field of the potentially transformed to 5 players; the final pairing, Oosthuizen (2 back), Watson (3 back), and Kuchar (4 back).
I gotta believe that the caterpillar/butterfly of this group would be Hanson, a relative unknown in the USA.