Thats what speed on the basepath can do for you. Force defense to make plays. Crazy how much we have with Mullins, Mateo, Westburg, Hicks, Frazier, Urias, Henderson and McKenna when he plays. Too bad Mateo couldn't get on base more often
Edit: I just looked this up and apparently Mountcastle is faster than Mullins (Mountcastle 28.1 ft/s Mullins 27.9 ) Also it doesn't appear we are particularly fast, with only one player (Mateo) in the top 50. The next we have ranked is Westburg at 62 followed by Henderson at 80. Also Frazier and Urias don't have particularly high ranks (in the 300s) Surprising.
https://baseballsavant.mlb.com/leaderboard/sprint_speed