It is difficult to define "win" in these political debates.
As I see it, there are three separate "scoring categories," two of which should be fairly irrelevant but aren't.
(a) Did the candidate seem "presidential"? Did s/he project an image of a Leader that the viewers would like to see in the White House?
(2) Did the candidate effectively communicate his/her points?
(iii) Was the substance of the candidate's points consistent with what the audience wanted to hear?
Contrast Trump with Walker. Trump was substantively made to look foolish (failed to back up his ridiculous claim about the Mexican government, failed to justify screwing his creditors out of billions through bankruptcy), but got generally positive reviews because many in the audience think bombast is leadership. Walker, from an accomplishments standpoint, was one of the top three people up there, but didn't look very "presidential" and didn't score well.
I wish this were like a tournament, where the losers have to go home and leave the future debates to those who did well. Hopefully, once there is some attrition it will be contagious.