Last year the defense was really bad at the end of the year, mostly because we were playing 7-8 guys who were walk ons who were not recruited by any school.
Prior to that the defense won games vs Utah, ASU, WSU.
The season before the defense was top 10 nationally.
Tuiaki is not a brilliant DC but he has a plan. His players understand his plan and play hard for him.
He gets scapegoated for stuff that is not his fault and is continually called out, mostly by people who think blitzing every play would solve all problems or think time of possession matters in football.