One of the most persistent rumors of this year’s trade deadline has been of a deal involving Denard Span and Washington Nationals closer Drew Storen. Storen is pretty consistently praised as an upper echelon relief pitcher: “an ideal long-term closing solution“, “young, cheap,…great upside, an [sic] shutdown closer“, and “about everything you could want – youth, a power arm, ability to get a strikeout and club-controlled paychecks for several years“. I knew very little about Storen prior to these rumors, and thought it would be informative to see how well he justifies the hype.
The #10 overall pick in the 2009 draft Storen flew through the minors, spending minimal time in A, AA, and AAA before making his big league debut with the Nationals in May 2010, less than one year after being drafted. John Sickels ranked him 3rd among Washington prospects prior to 2010, and Keith Law had him as the 92nd best prospect in baseball. In slightly over 100 innings in his career, Storen has posted a 3.15 ERA with 30 saves and has seemingly established himself as one of the premier young relief pitchers in the game.
I think I’m missing something, however, since his underlying numbers are less impressive. Using FanGraphs’ pitching leaderboards, we can see how Storen stacks up against the 138 other relief pitchers who have thrown at least 31 innings over the past two seasons. Listed below are Storen’s career numbers for a variety of pitching statistics, as well as where he ranks among all relievers over the last two seasons:
xFIP: 3.32 (51st out of 139)
tERA: 3.08 (44th)
SIERA: 2.89 (48th)
K/9: 7.92 (62nd)
K%: 21.6% (56th)
BB/9: 2.90 (45th)
Swinging strike%: 8.6% (81st)
FB velocity: 94.6 mph (25th)
Ground ball %: 45.7% (65th)
Especially concerning to me is his swinging strike percentage. This percentage is extremely highly correlated with strikeout rate (unsurprisingly) and is actually more predictive of future strikeout rate than strikeout rate itself (more surprising). While Storen’s velocity suggests that he should be able to generate strikeouts quite effectively, the swinging strike percentage shows that, at least thus far in his career, that translation has not been made. For comparison, former Twin Jesse Crain has the exact same average fastball velocity over the past two season as Storen, Crain has a SwSt% of 10.8%, ranking 35th among relievers. Also alarming is the fact that current Twins reliever non grata Matt Capps sports a nearly-identical-to-Storen SwSt% of 8.5% over the past two years.
Now, all of this is not to say that Drew Storen is a terrible pitcher: he is still quite young, very cheap, is praised by scouts, and may just need a bit more experience to turn his tools into production. While he may become a top closer, I’m not seeing the assertion that he’s already there. It’s definitely possible that I’m missing seeing, so let me have it in the comments if I am, but right now I’m seeing a reliever who’s (unsustainable) .221 BABIP this season is driving his gaudy 2.68 ERA and 0.95 WHIP, and would expect all those numbers to regress as the season goes on.