By comparison , Mariano Rivera converted 89 percent of his career save chances .
And since taking over for Matt Capps as closer in mid-2012 he 's converted 74 saves at an 89 percent success rate .
Mariano Rivera converted 89 percent of his career save chances .
And since taking over for Matt Capps as closer in mid-2012 he 's converted 74 saves at an 89 percent success rate .