BP Daily: Midseason bullpen report

There is no group of players whose performances are more volatile than relievers. Because of their small workload and variable handling, all but the most reliable of them vary wildly in effectiveness from season to season. They are also sensitive to the way they are deployed by managers. Two relievers with identical numbers are going to make differing contributions to the winning effort if one is used in close games and the other only when the team is ahead or behind by a large margin.