The Hit List: Undefeated Fighters in the UFC

Joanna Jedrzejczyk has filled the void in wake of Ronda Rousey’s unexpected fall.

Of the 648 fighters the Ultimate Fighting Championship lists on its UFC.com roster, only 28 of them -- 4.3 percent -- are undefeated and have posted at least one victory inside the Octagon. Jedrzejczyk, 12-0, has gone from virtual unknown to legitimate mixed martial arts superstar in less than two years. The 29-year-old Polish muay Thai machine captured the women’s strawweight championship when she bludgeoned Carla Esparza with punches in March 2015 and has successfully defended it on three occasions since, besting Jessica Penne, Valerie Letourneau and archrival Claudia Gadelha in succession. Jedrzejczyk has…