The Cubs saw their bullpen run full-speed into a brick wall late last year.
After serving as a strength of the team in the first 4-5 months of the season, the Cubs bullpen fell off a cliff and struggled mightily toward the end of the regular season and into the playoffs. They simply ran out of gas.
It was one of the main areas the Cubs looked to improve this winter, even as they lost Wade Davis, Hector Rondon and Koji Uehara to free agency.
Theo Epstein's front office added Brandon Morrow and Steve Cishek to the relief corps and brought back Brian Duensing, but it's all the underrated moves that are really paying off for the Cubs bullpen right now.