Talk to any of the former pitchers, not the current ones, about closing. No current pitcher is going to say that closers are a "different breed" or they need to have "stones of steel", etc. But retired guys will tell you that after the fact. I do believe closing takes a special mindset. The courage to throw pitches with meaning pretty much every time you're out there, the power to overpower the hitters, and a short memory of your defeats