2016: 4.90 YPP allowed vs all FBS opponents (14th in the country), 5.45 YPP allowed vs Ranked Opponents (21st in the country)
2017: 4.75 YPP allowed vs all FBS opponents (8th in the country), 4.44 YPP allowed vs Ranked Opponents (3rd in the country)
2018: 4.52 YPP allowed vs all FBS opponents (3rd in the country), 4.55 YPP allowed vs Ranked Opponents (5th in the country)
2019: 4.86 YPP allowed vs all FBS opponents (14th in the country), 5.53 YPP allowed vs Ranked Opponents (17th in the country)
2020: 5.41 YPP allowed vs all FBS opponents (41st in the country), 6.35 YPP allowed vs Ranked Opponents (37th in the country) ** Only Clemson was ranked when we played them this year
So, really no validity to this padding the stats vs bad teams thing. The defense has pretty much been who it's been vs ranked or unranked opponents. Yes, there's a slight increase in YPP allowed to ranked opponents in every season except 2018. But you'd expect that...they're better teams. For example, last year Ohio State led the country in YPP allowed vs FBS teams....in 14 games vs FBS opponents, they gave up 4.14 YPP.
But if you filter for all teams games vs ranked opponents, the number that led the country was 4.74 YPP. Makes sense. Everyone pads their stats against bad teams.