The winner will be announced before Game 4 the World Series, on Saturday, Oct. 28.
Jansen had his finest season in 2017, the first season of a five-year, $80 million contract he signed last winter to return to the Dodgers. He posted career bests in ERA (1.32) and FIP (1.31), tied for the National League lead with 41 saves and struck out 109 against only seven walks.
Among major league relief pitchers with at least 40 innings this season, Jansen was the best in ERA, FIP, FanGraphs WAR (3.5) and strikeout-to-walk ratio (15.57), was second in xFIP (1.82), SIERA (1.48), strikeout rate (42.6%), walk rate (2.7%), and K-BB rate (39.5%), ranked fifth in Baseball-Reference WAR (2.9) and was sixth with a .476 opponents OPS (a 29 OPS+).
The reliever of the year awards were reconfigured in 2014, named after Hoffman and, in the American League, Mariano Rivera. The voting each season is done by a panel of former elite relievers — Rivera, Hoffman, Dennis Eckersley, Rollie Fingers, Bruce Sutter, Lee Smith, John Franco and Billy Wagner. That’s a group of three Hall of Famers, plus two who will soon join them in Cooperstown in Hoffman and Rivera, and six of the top seven all-time in saves.