The Toledo and Tennessee games were essentially tossups, with 1 to 1 1/2 point spreads. In all other games, BYU was the underdog.
So it’s true that BYU has underperformed as a favorite, with a 1-1 record straight up and 0-2 against the spread (ATS).
In tossup games, they are 1-1, both straight up and ATS, which is what one would expect.
But as underdogs, they are 3-2 straight up, which is pretty impressive.