RealGM

http://nugglove.com/2017/06/04/denver-defensive-woes/
Article lists out some stats and tells us what we already know.

Picking my top 2 options in this poll is a little tough but I'm going to go with
#2 new defensive coach & system and
#5 get rid of anyone that doesn't play defense - that will send a message.

I think you have to get rid of the main culprits, Nelson is incapable of playing defense, Gallo and Chandler obviously felt it was not important, they all need to be gone and replaced by good defenders who's teams cannot afford them this summer.

To move from worst in the league bad to top 15, you basically need a roster or coaching overhaul