I keep hearing that Collins is not good on defense- but his defensive rating is pretty good and here is an excerpt from an article written last year from an analyst who rated him with an A on defense;
**When Collins entered the league, his defense was a cause for concern. That is no longer the case. Despite being undersized, occasionally playing the 5, and always playing cleanup for perimeter players, Collins is reliable on defense.
This season, Collins increased his defensive rebounds, steals, and held steady at one block per game. According to most advanced states, including
FiveThirtyEight's RAPTOR rating, only Clint Capela and Delon Wright were better defenders this season.
Collins is capable of playing defense without fouling while still providing adequate rim protection. Couple that with his switchability, and it makes him an integral part of the Hawks' defense.**