When you look back to about ten years ago, Solomon Torres is one of the first high leverage relievers that springs to mind. The Milwaukee Brewers also had the likes of Fransico Cordero, John Axford, Jim Henderson and Francisco Rodriguez anchoring their bullpen. All of them posted ERAs of a 3.70 or lower during their time in Milwaukee. Barnes is on pace to be better than almost all of them, and give Rollie a run for his money.
The recent emergence of Jacob Barnes is quite a fascinating spectacle, as he not only has a devastating fastball that he throws effortlessly in the upper 90s, but he also has what he calls a cutter, or slider that he can throw at an impressive velocity of 90 to 93 MPH.