Is Something Wrong with Jake “The Snake” Arrieta?
In 2015, Jake Arrieta won the National League Cy Young Award. In a season when Zack Greinke and Clayton Kershaw had magnificent years, Arrieta was voted to have had an even better one. Let’s revisit some of his simple numbers from that year: 236 strikeouts, 1.77 ERA, 0.865 WHIP. Jake Arrieta was a dominant pitcher in 2015. 2016 was a bit of regression for Arrieta, as his ERA rose to 3.10 and his strikeouts dropped below one per inning. Early on this season, Arrieta has regressed some more, but also progressed. His K/9 is higher than it was in 2015 or 2016, but his ERA his higher as well, up to 4.66. What gives?
Usually, when I want to figure out what’s going on with a guy posting weird numbers, I scroll through their Fangraphs page. On Arrieta’s, the first number to stand out was HR/9, along with HR/FB%. In Arrieta’s Cy Young year, his HR/9 was 0.39 with a 7.8% HR/FB. Those numbers rose to 0.73 and 11.1% last year. This year, amidst Arrieta’s early season struggles, they’re up to 1.86 and 21.4%. More than one of every five fly balls Arrieta gives up leaves the yard.
Beginning in 2015 and going on through this season, Arrieta has given up a higher percentage of batted balls being pulled each year. This year, it’s his career high, allowing 41.3% of balls hit against him to be hit to the pull side. That would be okay if it was because batters were rolling over on good secondary stuff. They’re not. According to Fangraphs’ hard hit percentage, Arrieta is at the second highest mark of his career, only trailing his 2010 debut season. 32.5% of balls hit against Arrieta are “hit hard,” and an even higher percentage of balls are pulled. The easiest way for a hitter to tap into power is to pull the ball, and obviously hitting it hard is any hitter’s preference. This season, basically more than any other, Arrieta is giving up more pulled balls and more hard hit balls than ever, and much more than his Cy Young 2015 and even his 2016.
After throwing a career high in innings in 2015, Arrieta was bound to regress some physically, along with statistically. Each of his pitches, from 2015 to 2016, and then from 2016 to 2017, has lost velocity. He throws his fastball 2.6 miles per hour slower, on average, in 2017 compared to 2015. That’s worrisome in its own right; after such a high innings count in winning the Cy Young, his arm obviously doesn’t quite have the same juice. But I don’t think that alone is the culprit for Arrieta’s struggles.
When Jake Arrieta won the Cy Young, much of the talk centered on his filthy cutter. When Arrieta was traded to the Cubs, they added the pitch to his arsenal; he’d never really throw it before. In 2014 and 2015, Arrieta’s two best seasons ERA-wise with the Cubs, he threw the cutter 28.3 and 29.1 % of the time. Last year, it was down to 17.8%, and this year down to 15.3%. His cutter has also declined 3.5 miles per hour since his 2015 version (though this could be slightly clerical, as it’s possible Arrieta is throwing more of a slider and less of a cutter than he was then). Comparing just 2015 to 2017, Arrieta has increased both fastball and changeup usage to compensate for less cutters.
How do all these pieces come together?
When Arrieta was at his filthiest, his cutter was impossible for batters to hit. Coming in at over 90 miles per hour with late movement, batters rarely squared the ball up; it moved away from their barrel at the last second. That means less hard contact, and with the ball moving away from them, usually less pulled balls. Now featuring less cut and more straight fastballs, Arrieta has gotten rid of that advantage of his awesome cutter. The ball no longer darts late to avoid barrels. Reduced velocity and less deception give the batter more of a chance to turn on the ball. 2017 Jake Arrieta is simply more hittable than 2015 Cy Arrieta.
I struggle to believe that Jake Arrieta will finish this season with a 4.66 ERA. A HR/FB% over 20% is ridiculously high for almost any pitcher to run for a full season. Only Jaime Garcia was above 19% last year. But the stuff that brought Arrieta to a Cy Young in 2015 is long gone. I don’t know why he’s not throwing his cutter as much anymore. I’d love to ask him. But the reality is that he isn’t, and all his pitchers are slower than they were. His ERA will definitely finish higher than the 3.10 he concluded 2016 with.
I’m guessing that anyone who owns Arrieta is hoping for a rebound, especially if they had him in 2015. It’s hard to get the idea of that stalwart version of Arrieta out of your head. If you can get Arrieta for the price of a guy with a 4.66 ERA, do it. But more importantly, if you can sell Arrieta like the guy who won a Cy Young, do that for sure. He’s not a bad pitcher, and he’s got a good offense and defense behind him, but Arrieta no longer possesses the same ability he had that won him the Cy Young. His career will never again reach the heights, individually, that it did in 2015.