Oregon and Utah each have star skill position players. The Ducks with QB Justin Herbert. The Utes with running back Zack Moss. 
But the key to the success of these two teams is defense. Oregon surrenders fewer than 16 points a game. Utah is even more stingy yielding 11.2 points, third-best in the nation. 

It's not just two outstanding defenses that make the Under a good play here. Utah is heavily run-oriented, playing slower than any team in the nation as far as milking clock. 
The other factor is weather. This game is being played at Levi's Stadium in Santa Clara. This is a grass field not known for providing good footing. The forecast is for rain and wind.