The Domination of the Other Phelps

Coming off a season in which he pitched to a 4.50 ERA mostly out of the starting rotation with only 6.19 strikeouts per nine innings, the Marlins decided it was time for a change for David Phelps. They moved Phelps to the bullpen full-time to begin this year, and he was on his way to becoming a relief ace before the Marlins sent him back to the rotation. In 50 relief appearances before joining the rotation, Phelps averaged a whopping 11.43 whiffs per nine (69 strikeouts in 54.1 innings!). Since joining the rotation, Phelps has nine whiffs in 9.1 innings. It will be interesting to see if he can keep this up in the rotation (a la Danny Duffy), because the main culprit for this increase in strikeouts is a surge in fastball velocity:


It’s a classic case of a pitcher’s stuff playing up in a move to the bullpen. Before this year, Phelps never even averaged 92 on the heater. Now, he’s close to 95. I’m hopeful that he’ll maintain this velocity surge because of what Danny Duffy has done this year. Last year, Duffy averaged around 94.5 on his heater and a mere 6.72 K/9. This year, he’s up to around 96 and 10 in those two categories, respectively, despite being shuttled to and from the bullpen his entire career (just like Phelps). There were plenty of concerns that Duffy’s stuff wouldn’t last in a move from the bullpen this year, but I think his 16-strikeout performance on August 1st quelled the last of those concerns.

Alas, a hard fastball isn’t enough to make a great pitcher, as the Yankees realized when they included David Phelps as a throw-in for Nathan Eovaldi. Now, they’re actually of a similar level of skill. Phelps’ four-seamer has decent arm-side movement, but Eovaldi’s has more. Both of their four-seamers generate close to a 20% pop-up rate, which is really good (average for a pitcher’s full arsenal is around 9.6%). Phelps’ four-seamer’s whiff rate has gone up: it was never higher than 9% (a mere 5.6% last year), but this year it’s nearly 13% (Eovaldi’s is at around 7.8% this year).

Here’s what Phelps has that Eovaldi doesn’t have: decent secondary stuff. Phelps’ second-most-frequent offering is his sinker, which has the eighth-best horizontal movement for sinkers of pitchers with at least 60 innings this year (according to FanGraphs). The whiff rate is up to its highest point ever (although only near 6%). He throws it hard, as it’s averaging over 94 this season. The GB% has never actually been good, but it’s up over 50% this year for the first time. The kicker is this: his sinker has allowed an incredibly low ISO this year (0.036). Who knows if the newfound power-suppressing/added groundball-getting ability will continue for the pitch, but even if it doesn’t, sinkers and four-seamers usually work really well together. This is part of how Phelps distances himself from Eovaldi — Eovaldi has no sinker!

Phelps also has a solid curve, which is generating its best whiff rate since his rookie year, at 11.3% this year. This year, it also has the most vertical drop and cutting action away from righties of his career. Of the 191 pitchers who have thrown at least 100 curveballs this year (sample from Baseball Savant), Phelps’ deuce has the 28th-highest spin rate (2616 revolutions per minute), well above that group’s average of about 2243. And boy, does that thing get grounders. Its average launch angle this year is -7.0! That’s good enough for the third-lowest among my curveballer sample. Brooks Baseball has its GB% at nearly 77% this year, and it has only dipped below 60% one season in his career.

His other pitch of note is a cutter/slider thing (he also has a change, but he’s only thrown it 14 times this year). It has good rise. It doesn’t get too many whiffs, but it’s at its highest whiff rate since his rookie year (close to 9%). The ISO against it has only gone above .100 one year, and is solid this year at .090. It gives him a bit of a new velocity band, as it has usually come in around 91 this year. It also gives him a different kind of movement from his other fastballs (FF=four-seamer, FT=sinker, FC/SL=cutter/slider thing, KC=curve, CH=changeup):


The bottom line is this: Phelps has always had decent secondary stuff, but before this year, his fastball kind of sucked. Everything plays off of the fastball well, so as his fastball has improved, his secondary stuff has improved too. If Phelps can maintain this added velocity, I see a bright future for him.

Data from FanGraphs, Brooks Baseball, Baseball Savant, and Texas Leaguers. If you have a moment, read the awesome article that I linked from The Hardball Times:

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The author's name is not, in fact, actually eyesguys1. Rather, he goes by Alex Eisert. He is a Yankee fan, but tries to remain impartial. You can reach him on Twitter... @yankeefan2400

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