Looking at negative yardage plays, with pace of play factored in:

Most "Disruptive" Defenses (through Week3)

16.3% Illinois
16.1% Boise St
15.7% Ohio St
15.5% UCF
15.1% Florida
15.1% Mich St
15.1% UVA
14.8% App St
14.6% Miami
14.6% UAB
14.6% USF
14% PSU
14% San Diego St
14% TCU

— Pick Six Previews (@PickSixPreviews) September 18, 2019