The last year he was a defensive coordinator, BYU finished with the 33rd-best passing defense in the country (in S&P+):

The list is compiled from the 2013 schedule in order of their S&P+ passing rankings and listed with their season passing efficiency total (and their passing efficiency against BYU in parentheses):

15. Notre Dame 132.26 (128.76) - was average
38. Washington 150.30 (111.61) - did WAY WORSE than average
40. Utah 121.93 (152.95) - did WAY BETTER than average
42. Wisconsin 133.75 (127.39) - was average
47. Texas 117.73 (129.30) - did BETTER than average
48. Georgia Tech 122.16 (108.30) - did WORSE than average
53. Boise State 150.78 (117.91) - did WAY WORSE than average
54. Nevada 138.16 (139.56) - was average
62. Houston 132.11 (159.02) - did BETTER than average
62.5 MEDIAN AVERAGE
85. Middle Tennessee 121.96 (76.82) - did WAY WORSE than average
96. Utah State 135.24 (86.91) - did WAY WORSE than average
114. Virginia 96.09 (90.24) - was average

So, 9 of our 12 FBS opponents had above-average passing offenses - with only 1 top 25 passing offense so Bronco had plenty of opportunity to display his DC prowess against good passing offenses.

Against the teams that stunk at passing, we did very well.

3 of the 9 better-than-average passing offenses did even better than their season averages, but 9 of the 8 also did worse to way worse than their season averages with the other 3 right on par with what they normally do. That is not a bad track record - not great but still pretty good (33rd in the country).

In 2012, BYU finished with the 14th-best passing defense in the country. Here is the list of our opponents that year:

5. Notre Dame 128.68 (113.51) - did WORSE than average
8. San Jose State 170.26 (172.12) - was average
13. Georgia Tech 143.48 (44.67) - did WAY WORSE than average
17. Oregon State 140.36 (180.59) - did WAY BETTER than average
22. Boise State 141.85 (104.54) - did WAY WORSE than average
37. Utah State 153.25 (94.79) - did WAY WORSE than average
56. San Diego State 136.38 (62.40) - did WAY WORSE than average
62. MEDIAN AVERAGE
79. Utah 127.37 (152.09) - did WAY BETTER than average
90. Idaho 110.54 (97.65) - did WORSE than average
95. Washington State 117.01 (100.52) - did WORSE than average
114. New Mexico State 123.24 (136.97) - did better than average
122. Hawaii 103.04 (70.64) - did WAY WORSE than average

So in 2012, BYU faced 7 FBS that had better-than-average passing offenses - but 5 of them were top 25 passing machines (2 in the top 10). Of those 7, 5 did worse to way worse than what they normally did all season (3 of them with top 25 offenses) with 1 of them better-than-normal (also top 25) and the 7th right on average (also top 25).

That is pretty darn good pass defense. Granted, that was the year that we were playing multiple NFL talent players - on the D-line, among the LBs and in the secondary.

When Bronco has the pieces, he can field an elite defense - against the pass as well as against the run. When he doesn't have as much talent - especially on the D-line, he still does very good. What we're seeing this year is that he has given up playcalling duties with a defense that hasn't been nearly as talented as in the recent past.