We win because we shouldnt.
Seriously though ... if Mark Andrews gets hurt early, Sweat/Kerrigan play lights out on the edge, IDL contain Dobbins/Ingram, we get a ST touchdown, Harbaugh goes for it on 4th downs and misses on them, and Turner's play calling from the 1st half last game carries over.
^^ if that happens, we beat the 14 point spread.
Like taking money from a baby.