Astros: Investigating Gerrit Cole’s Struggles in 2017


Ever since posting a 3.07 ERA in his first three seasons in the majors, Gerrit Cole has struggled. Will a change of scenery be enough to right the newest Astros pitcher?

After breaking onto the Major League scene in 2013, many believed Gerrit Cole would be the next young ace. He started 19 games for Pittsburgh and posted a respectable 3.22 ERA. And at 24, after starting 32 games and pitching to a 2.60 ERA, it seemed he had arrived. Now he joins the Astros to win another championship in 2018.

But his stay among the top pitchers of the game was short-lived. The past two seasons have been mediocre at best for Cole. A 4.12 ERA in that span can attest to it. But what has caused his dramatic drop-off?

What worked for Cole in 2015?

Gerrit Cole was an absolute horse in 2015. He would win 19 games for the Pirates and finish fourth in the NL Cy Young voting. But what worked for him? Cole’s fastball was effective, limiting hitters to a .246 batting average. However, his slider and sinker were devastating.

Opposing batters had a .195 batting average against his slider in 2015, and slugged only .287. His sinker was equally effective, limiting hitters to a .217 average and slugging percentage. He combined to throw these pitches 907 times, or 28 percent of his total pitches thrown in 2015.

But the 2016 season was a different story. Hampered by a strained right triceps, Cole missed a month of time. His ERA increased from 2.60 in 2015 to 3.88 in 2016, and his strikeouts per nine dropped from 8.7 to 7.6. But while Cole did start 33 games in 2017, it seems his 2016 injury is still affecting him.

Impact of Cole’s Injury

We’ve already looked at a broad overview of Cole’s 2016 season. But if we take a closer look, some alarming trends start to carry over from 2016 to 2017. Cole’s most dominant pitches in 2015 were nowhere near as effective the following season.

Opposing batters hit his slider at a .281 clip, and slugged .416 against it. His sinker was also lit up, with hitters mashing it at a .294 batting average. Even so, Cole still had a dominant out pitch. His knuckle curve left hitters baffled, as they hit .188 against it.

Much of Cole’s struggles in 2016 can be placed on his strained right triceps. But in 2017, that was not the case. Cole made the most starts of his career and had 203 IP. Could Cole’s injury in 2016 have affected his mechanics in 2017?

Cole’s Struggles Continue

It’s hard to know that for sure. But it seems like something was off with Cole in 2017. The former Cy Young candidate was a shell of himself, posting a career-high 4.26 ERA and a startling 1.4 home runs per nine innings. Even in 2016, Cole’s 0.5 HR/9 is within his career averages.

The main culprit for Cole’s high HR/9 rate? His fastball. Cole hasn’t lost much speed on his fastball, averaging around 96 mph for his career. But it has lost some movement. His fastball limited opposing hitters to a .247 batting average in 2014-2015. That batting average against his fastball jumped to .268 in 2016-2017.

Hitters are also slugging much better against his fastball. Opposing hitters slugged .360 against his fastball from 2014-2015. Since then, it has jumped to a .431 slugging percentage. It is clear Cole has lost something with his fastball. But there may be a way for Brett Strom and company to return Cole to his dominant status.

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Returning Cole to his former self

Even though Cole’s slider was ineffective in 2016, Cole was able to regain some of its dominance in 2017. Hitters batted .230 against his slider and had a 19 percent swing and miss rate. That is a useful pitch, and one Cole should utilize more in 2018. Another pitch that could be effective for Cole is his sinker.

This once dominant pitch was lit up in 2016, as he induced only four swings and misses out of 123 sinkers thrown. Apparently, the pitch was so ineffective that Cole eliminated it from his repertoire in 2017. Cole’s sinker was one of the nastiest in baseball in 2015. But by 2017, he stopped throwing it altogether.

Next: Astros: What we can expect from Derek Fisher in 2018

The Astros don’t need Cole to be an ace. With Justin Verlander and Dallas Keuchel, all Cole has to do is be a solid 3-4 starter. But to get there, he will have to improve his fastball movement and possibly resurrect his sinker.

***Statistics provided by Baseball-Reference and Baseball Savant***