Mackenzie Dern praises Charles Oliveira as the best grappler in the sport: ‘He has the best jiu-jitsu in MMA’

As a multi-time Brazilian jiu-jitsu world champion, Mackenzie Dern possesses some of the nastiest grappling skills in the entire sport of mixed martial arts. So it’s safe to say the 29-year-old UFC strawweight has a more than valid opinion when it comes to rating the best submission specialists in the sport. When asked to name the fighter with the best…