During the 2015 season, I debuted a metric I coined RWAR (Relief Pitcher WAR), which uses RE24 and leverage index to determine the most valuable relief pitchers in terms of a standard WAR scale. The article in which I debuted the concept can be found here. With the 2016 season a little over halfway gone, I thought today would be a good day to peak at the 2016 leaderboard.
Many of these names are unsurprising to see at the top as guys like Britton, Davis, Miller, and Jansen are considered to be among the best relief pitchers in the game. Also rather unsurprisingly, most of these pitchers are their teams’ closers. Although in some cases, as evidenced by the top ten above, guys who do not occupy the typical closers role can be just as valuable to their teams. While Harris recently took over as the Houston Astros closer and Miller was the New York Yankees closer to begin the season, both have accrued significant value in setup roles. Additionally, Herrera and Brach have combined for two saves (both Brach), accruing essentially all of their value as the setup men for their respective teams.
Another item of note: both the Baltimore Orioles and Kansas City Royals have two members of their bullpens who make the top ten list. This kind of elite late inning bullpen has been a staple for both teams in recent seasons, showing one explanation as to why both teams have continuously outplayed their projections and run differential expectations.
On the other side of the coin, lets take a look at the relievers who have hurt their teams the most this season.
While the top ten list was littered with players on teams that in playoff contention, the bottom ten contains a number of guys who pitch for bad teams. The Reds and Padres each have multiple pitchers among the worst in the league in RWAR and are considered by many metrics and rankings to have two of the worst bullpens in all of baseball. The fact that Rosenthal finds himself at the bottom of this metric should not surprise many St. Louis Cardinals fans, as the hard-throwing right hander recently lost his job as the team’s closer. Rosenthal was among the best relievers in the game when I debuted this metric; his terrible season this year as well as Rodney’s excellent start to the season shows the volatility in relief pitching and how difficult it is for a team to build a truly elite bullpen year in and year out. While building a pen can be difficult, several teams have shown that an elite pen can put an “average” team over the top.