It would be interesting to see how well this system plays out in college football vs. college basketball but I would certainly believe that both percentages are well above 60% and profitable when played blindly in the long run.
As far as this game goes, you gotta like the home team here. . . just because NIU is 7-0 doesn't mean they will go 8-0! Also, BG played the defending national champs so I don't believe one loss looks that much worse than what NIU has done this season.
In addition, when looking at this line, remember that Vegas adjusts lines based on anticipated public perceptions. . . so where would Vegas move the line once the real line is determined: in BG's favor or NIU's? I think the answer is obvious as NIU has had the greater exposure espcially with the huge early win over Maryland.
In the end, the line value is clearly with BG. . . even at -4 which I was surprised to see as well. There will be a lot of suckers in Vegas this weekend putting their money on the NIU ML to make some big money based on their perfect record so far and all they're gonna do is lose it!