In big games when teams are really good matchups win championships. In big games when teams are really good big plays win championships. In big games when teams are really good field position wins championships. Etc., etc., etc…
The given to win a championship is you have to be very good in most aspects of the game. The QB is always more important than any position on the field because they are in control of the play and the matchups. Everyone else is reacting if the QB can make the correct read and execute the play.
At the end of the day you better be a very good, balanced team with a QB playing very well to get through 3 or 4 playoff games to win a Championship. Having a QB who is anything less then at the top of his game and his game better be real good is at a decided disadvantage in trying to win a SB.