Ronda Rousey says her next fight on at UFC 207 on December 30th against Amanda Nunes will be one of her last. In May 2015 Ronda told Sports Illustrated she's had arthritis since she was 19 years old and has had four knee surgeries. In the past she talked about not wanting to fight once she hits around the age of 31. Ronda is currently 29 years old and turns 30 on February 1st. She started MMA at 22 years old but began doing judo at the age of 11. The one deemed by some as The Next Ronda Rousey, and who teammate Benson Henderson says will be bigger than Ronda, is 23 year old MMA fighter and multiple time jiu jitsu world champion, Mackenzie Dern. She has been doing jiu jitsu since the age of 3 and holds multiple gold medals in the sport including a 2015 ADCC title, 2 golds in the world jiu jitsu championships and 2 in the world no gi championships. She is 2 and 0 in MMA and is looking to earn a spot in the UFC strawweight roster in 2017. Link: https://www.youtube.com/watch?v=2R