Oh cool, you guys forgot how this process works since Utah has been out of the big dance for so many years. Don't worry, I'll fill you in. 68 teams. There is thing called an RPI that is a pretty big deal. BYU is hanging on the edge of the 68 as is, but would move up considerably if all they do is lose to Gonzaga for the rest of the year. They got 3 straight home games that will kick them into the low 50's if the win. If they then beat Portland on the road and play Gonzaga regardless of a win, they are into the 40's before the conference tourney. Then if they can just meet Gonzaga at some point in the conference tourney, that will automatically kick them up higher - low 40's; high 30's most likely. They are in. Beat Gonzaga either time and they can lose 2 more games to anybody.
Overly simplified. The NCAA tourney has 32 automatic bids (winning their conference). If BYU doesn't earn their conference, they will be faced with a number of factors, including SOS, W/L, A/P rank, RPI, end of season performance, etc..
They will likely need to be in the top, say, 25 of RPI, at least, because their SOS will be meh and the W/L will be as well. Of those 32 auto-bids, only about half will actually be better than BYU.. so BYU has to be that much better than the 'rest' to make it in.