Did Jeremy Hellickson Really Improve This Year?

Around this time in 2015, right-hander Jeremy Hellickson had just completed a three-year stretch during which he recorded a cumulative ERA near five and experienced some injury troubles to boot. Following his one and only season in Arizona, he was traded to Philadelphia for a young righty who wasn’t even among the Phillies’ top-25 prospects at the time. There wasn’t a great deal of reason for optimism.

A year later, circumstances are considerably different. Following a three-win season, Hellickson received a qualifying offer from the Phillies — and now the 2017 edition of Hellickson will earn $17.2 million. The results were pretty different, in others words. But what about the process? Are these the same Hellicksons?

At one important level, Hellickson has hardly changed at all — over the course of his entire career, actually. Focus only on strikeouts and walks, and last year wasn’t really all that different for the Phillies’ righty. Going into last season, he’d struck out around seven batters per nine — and walked fewer than three — over the course of his career. This past season in Philadelphia, he struck out around seven batters per nine and walked closer to two. So maybe the difference in 2016 was just a couple fewer walks, fortunate sequencing and better luck overall?

Let’s delve a little deeper into the standard peripherals we use to look at these things, though. Immediately, some subtle changes present themselves.

Jeremy Hellickson’s Career in Thirds
K% BB% K-BB% HR% GB% PU%
2010-2012 16.5% 8.4% 8.1% 3.1% 38.2% 5.5%
2013-2015 18.7% 6.9% 11.9% 3.3% 40.1% 2.7%
2016 20.0% 5.8% 14.1% 3.1% 40.7% 7.6%
PU% is pop-up rate, or infield fly balls per ball in play. 3.4% is average.
K-BB% is strikeout-minus-walk rate. 12% is average.
HR% is home runs per batter faced. It peaked at 3.03% in 2016, after hovering around 2.3-2.5% before.

If you look at Hellickson’s strikeout and walk percentages, you’ll find more growth than you might have expected if you were just scanning his “per nine” rate stats. That’s because strikeouts per nine are inflated for pitchers who walk more batters. That makes sense: pitchers who issue more walks get more chances to strike guys out “per inning.” On a per-plate-appearance level, though, there’s been real growth in Hellickson’s ability to limit walks and strike guys out. He’s gone from well below average to top 35 this past year.

Obviously, there’s more to it than that. For one, Hellickson rediscovered his ability to induce pop-ups — and did so without any homer penalty. In fact, as the league around him gave up more home runs, Hellickson improved by staying the same in that department.

Hellickson got the pop-ups back by pitching inside more. It’s noticeable against righties, but the change in approach really pops against lefties. Look at his fastball location against lefties from 2013 to 2015 (left) and then in 2016 (right).


For those of you yelling at the monitor right now, yes, it’s likely that we’re looking at the effect of a new pitch here. The raw PITCHf/x data don’t reveal a difference, but over at Brooks Baseball, they’ve detected the addition of a cutter to Hellickson’s repertoire. Cutters don’t fade toward the arm side like other fastballs and are therefore useful against opposite-handed hitters — you can throw them in on the hands and they won’t run back over into the heart of the zone.

The cutter is why Hellickson has more than doubled his pop-up rate against lefties this year (6.2% last season vs. 2.7% from 2013-2015) while merely improving his pop-up rate against righties (3.7% vs 2.8%).

It’s interesting because Hellickson has used the cutter before (2012), and the pitch doesn’t seem particularly impressive when judged on its own merits. It gets almost half the whiffs of an average cutter (4.9% vs 8.7%), none of the ground balls (27% vs 40%), and was batted for a line drive 42% of the time it was put in play.

Put up against Hellickson’s curveball, which has the fourth-best spin in the game (minimum 100 thrown), and his changeup, which had the highest swinging-strike rate among starting pitchers last year, the cutter seems a little wimpy. You might pause before you believe he’s really changed much if you see that a below-average pitch is the source of much of his improvement, even if the addition of a pitch alone — everything else being equal — helps starters improve their chances the third time through the order. The pitch doesn’t even look impressive.

But he already had the put-away pitches. He just needed to get his pop-ups back. If you add those pop-ups (divided by total batters faced) to his strikeouts and subtract walks, Hellickson zooms up to 31st out of 74 qualified starters by that measure. That sounds like the average pitcher his career suggests he can be (his career ERA is 1% better than the league’s).

So the return of the cutter has brought the pop-ups back, and the return of the pop-ups mean Hellickson likely profiles as a league-average starting pitcher. That’s not the greatest ROI for $17.2 million, but the supply of league-average starters is also very low this offseason. Only two remaining free-agent starters managed even an average season in 2016.

A tough three-year stretch, an iffy new pitch, and the return of the pop-up: that’s how you end up with a pitcher taking the qualifying offer. If he shows the same skills another year, he’ll be looking at multi-year offers next offseason.

With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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7 years ago

While the ROI of an average player for 17mil is virtually 0 (market value, maybe a little on the costly side), it has midseason trade upside. If he has a good start to the year, they can get a decent prospect out of someone, maybe even better than the pick they’d have gotten if he had turned down the QO. And from Hellikson’s standpoint, he wouldn’t be shackled by a QO next off season if he’s traded.