The line seems a little shocking but it makes some sense. It’s expecting Duke to score in the 20s and Miami to score in the 40s.
Besides Middle Tennessee (45), Duke has never scored higher than 26/27, and a couple of those were in OT. Any defense with a pulse should be able to contain them.
On the flipside, Miami’s 36 points against FSU last week was a season low, with perhaps Cam Ward’s worst performance of the year. Even then we won by 22, even after a garbage time TD.