Sans has 2 rooks and a queen left (the queen looks like a rook cause' I was lazy) and Undyne has 2 pawns and a lipstick taking the place of a rook.



Here's the deep symbols of it. We're right near the end of the match. Undyne, though obviously defeated, fights on, for the sake of fighting on. Sans, however, knows her every move, every move in every game she will ever play against him.



However, this means he never gets to play a game based upon his wit alone. He only comes out successor because of what he knows. So -he- can't win. Undyne, by always fighting, always learning on her own, despite losing every match, plays each herself, and therefore is the winner every time.



WHAT A TWEEEST!