The UFC heavyweight division is forefront at this weekend’s upcoming effort in Houston thanks to a headlining bout between champ Cain Velasquez and Junior dos Santos as well as featured fights involving Shawn Jordan-Gabriel Gonzaga and Daniel Cormier-Roy Nelson. While all six UFC 166 scrappers have strike-based stoppages to their credit, only two can be considered knockout artists, joining a core group of competitors packing cement in each glove. Some are one-dimensional, some are well-rounded, but all are among the UFC’s hardest hitting heavyweights. (Photos by USA Today Sports Images)