There is literally no data from which these percentages are reasonably derived. At best, these projections are based on 2015. A year after which coaches changed programs, Seniors have graduated, recruits have yet to reach campus, and nary a down (that counts) has been played.
Boston College is an early favorite 7 months ahead of time only because of the perceived strength of their conference (They play FSU, Clemson, Vtech, and NC State) and because it is being played in Chestnut Hill.
Sure BC returns a stout defense, but the leader of that defense (and offense for that matter), the man who knew his players the best, the man who called the formations and personnel packages, is gone. so are plus a number of position coaches. How important is the loss of Coach Brown? UConn went from the #5 ranked defense - based on yardage - in 2012 to #27 in 2013 after Brown went to BC. In terms of scoring, UConn went from #27 (<19 ppga) to #86 (>30). BC gave up 15 ppg last year.
The other reason they are favored is because it is a "home game." Dare I say that unless BC restricts ticket sales to credit cards addressed in the 01--- and 02--- zip codes, UConn will make up far more than their allotment of tickets and BC will have a home game in name only.
The only game that I believe UConn has a less than reasonable shot at winning is at Houston. Cinci is at home, so I give UConn a puncher's chance. Navy lost their all-world option QB as well as (I think) their entire starting offensive line. Virginia? Bronco Mendenhall knows UConn, but he has a new roster and it isn't filled with 26 year old men this year. Also, a UConn team built on the back of sophomores went toe-to-toe with BYU last year for 51 minutes and were a bonehead penalty from having a chance at a game tying drive. Familiarity cuts both ways. Temple is a home game plus the owls lost 26 seniors, Tyler Matakevich among them. Finally, and this is just a gut feeling, I think South Florida is grossly overrated.
I think 7-5 should be the floor of expectations. 8-4 is completely reasonable, and dare I say upwards of 10-2 is within reach.