I was going to ask the WPA question today of the American League MVP race, which is to say I was going to ask which of Shohei Ohtani/Vladimir Guerrero Jr. has improved his team’s win probability by more, an unpredictive but effectively meaningful measure of a player’s value.
Then, I noticed Josh Hader.
At the top of the leaderboard.
To be clear, Josh Hader is not leading the major leagues in Win Probability Added. Fernando Tatís Jr. is leading the major leagues in Win Probability Added. Josh Hader is in second place. Josh Hader, he who has thrown not even a third of the innings second-best (by WPA) pitcher Max Scherzer has thrown. Josh Hader. Second-most WPA in the leagues.
It turns out this isn’t unusual. Over the last decade, relievers took home the WPA crown among pitchers six times. Tyler Clippard did it in 2011. Jim Johnson did it in 2012. Zack Britton did it in 2016. Kenley Jansen was the guy in 2017. Blake Treinen led in ’18. Will Smith in ’19.
Jim Johnson was not the best pitcher in baseball in 2012. But while he was on the mound, his team’s fortunes improved more than was true of any other pitcher. He had just a 3.25 FIP. His 2.49 ERA was good, but not outrageous. Yet he was, by one measure—a measure that quantifies a player’s performance in terms of wins relative to the average, expected performance—the most valuable man on any mound anywhere. Which brings me to a possibility:
WAR is very good at measuring how good a player is. fWAR even measures it rather independently of luck. But I wonder, looking at this, if WAR leads us to undervalue bullpenners. If perhaps some of that conventional wisdom was correct. If there’s something with WPA that makes it important to have guys who can handle the eighth and ninth innings, and other moments of notable leverage. It’s possible I’m missing something with the logic here, and yes, I know WPA is not as good as WAR at measuring how good a player is (as I’ve said already in here). But it does make me wonder. About Josh Hader. About Jim Johnson. About Tyler Clippard. And about Max Scherzer. And whether he, or a future man like him, might be used in a higher-leverage manner.
