Back up plans
Change is good. doing the same thing over and expecting different results is never good idea, especially when someone is trying to knock you unconscious. Roy Nelson and Carla Esparza cannot rely on one tool for every opponent. Her wrestling and his right hand are good, even great, but not perfect. They are not going to work on everyone. Roy has a Black belt in ju jitsu that he never uses. Overeem was able to do what he does best and throw those knees knowing all he had to do was avoid the right hand. Carla became predictable and desperate when Joanna Jedrzejczyk walked her down knowing the only thing coming was another takedown attempt. Joanna has obviously worked on both, with striking that crisp and take down defense that good. Fighters like Werdum, Chad Mendes and Rafael dos Anjos are the fighters that are changing, adapting, winning fights and in some cases titles.