There are some SOS metrics that rate last year in the 60s. Based on track record, though, I feel like Phil Steele and Bill Connely are two of the more accurate in this regards. 48 and 56 are both in the same ballpark and seem like a reasonable estimate for our SOS last year. Our SOS this year looks to be a little bit tougher than last year.
FYI, some of the teams projected to have a weaker schedule than BYU this coming season according to Phil Steele:
Penn St
Alabama
Oregon
Oklahoma
Notre Dame
Utah
Nebraska
Clemson