Struggling Pitchers: Part 1

Kyle Hendricks, throughout his career, has been a rather unique pitcher in MLB. Despite the large increase in hard-throwing power pitchers, Hendricks has maintained the less-flashy but equally effective style of finesse pitching. Hendricks has a 4 seam fastball that tends to hover around 86 mph, yet due to his ability to locate pitches, along with a strong sinker and changeup, Hendricks has continued to succeed. And yet, after five seasons of mastering his craft, the 31 year old is struggling mightily this season. His percentage of barrels given up has increased from 4.5% in 2020 to 11.5% in 2021, and hard hit balls have climbed from 32% to 36%, as well as giving up many more home runs. First, let's take a look at why this is.

These images, along with two more I'll be showing later, come from the Baseball Savant website (link: baseballsavant.com). The image on the left displays Hendricks' pitch locations in 2020 on his 4-seam fastball, with the red areas displaying where the pitch was more frequently located, compared to blue areas of where the pitch was rarely located. Without major velocity, this is exactly what you want to be doing with a 4-seamer. Painting the outside corner for lefties, establishing the inside on righties, and pounding the zone. This can attest to his success in 2020. However, looking at the image on the right, which shows 2021's 4-seam fastball for Hendricks, he's making a couple large mistakes. For one, he's hitting the inner third of the plate to righties far less, and even missing the zone entirely. This can explain his sharp change in walk rate, from being in the 99th percentile of the league in 2020 to a more mediocre 74th percentile this year. But the bigger issue is that red oval that's in the middle of the plate, and slightly elevated. When throwing to the best hitters on the planet, it's really not in your best interest to serve up 86 mph fastballs right down the middle.

The problem of serving pitches right down the middle is even more prevalent on Hendricks' sinker. He did throw down the middle occasionally in 2020 (left), but not nearly as much as 2021 (right). The direct center of the strike zone has an alarming amount of red. And keep in mind, Hendricks has been in the bottom 10 percent in fastball spin rate for the past 6 seasons (including 2021). Meaning, his fastballs don't have too much crazy movement, and if they aren't located great, hitters can see them extremely well.

While I would chalk the increased barrel and hard hit rates up to pitch location, I'm not quite ready to say the same about his increased number of home runs given up. The league average for home runs to fly ball ratio, or HR/FB, is around 10%. This season, Hendricks's HR/FB is 28%. The textbook definition of an outlier, especially considering he has never eclipsed 14.8% in a single season ever. To understand what this means, HR/FB is more of a measure of luck than skill. When pitchers have a HR/FB that is incredibly high or low, it tends to even out as the season goes on, especially if it is an outlier within that player's career. HR/FB is one of those stats that you have to give a large sample size before viewing it to evaluate a player's skill. If this had been happening for Hendricks' entire career, there would be a different discussion happening. However, it has increased sharply in a small time frame. I'd certainly expect the home runs allowed by Hendricks to regress to the mean by the season's end. Hitters hitting the ball hard off him is something he'll have to fix, but the increase in home runs given up I would simply attribute to bad luck, whether it be the Wrigley winds or something else beyond the pitcher's control.

Now that we've correlated each aspect of Hendricks' struggles to a statistical reason, I'd like to go beyond the stats, and discuss what's going on between his ears. I certainly don't attribute all of his struggles to the mental aspect of the game, and there's a possibility that none of what I'm about to say is even relevant, because Hendricks is the only one who knows what Hendricks is thinking about. Yet I still find this element worth mentioning

While this isn't to undermine Hendricks' success, he has never been an ace in Chicago. Whether behind Jake Arrieta, Yu Darvish, or Jon Lester, Hendricks really hasn't had the opportunity to be the Cubs' go-to guy. That is, until Yu Darvish was traded to the Padres in the offseason, leaving Hendricks as the best man standing. Spending 6 seasons successfully undertaking the 2 or 3 starter role, and then suddenly switching to an ace could be tough on Hendricks. Since he's never left the Cubs and always been in that 2 or 3 starter role, he's in unfamiliar territory for the first time since he entered the league. He's had some strong outings, such as the 7-inning complete game against the Dodgers recently, but it's been inconsistent so far this season. I wouldn't be surprised if entering the ace role is part of that. Which is why I think Hendricks will figure this all out. Once he gets familiar with the role, I would expect him to start locating his pitches better, and over the course of that his luck will get better on fly balls, leaving the Cubs with the same pitcher they came into the season with. Not only is this data coming from a small sample size, but you have to let the guy get settled before expecting results.

Hendricks has always been an intriguing pitcher to me, because he clearly has baseball IQ. Some pitchers have enough talent to mindlessly throw hard fastballs or deep-cutting breaking balls. Hendricks doesn't have that kind of talent, so he has to be constantly thinking out there. And it's fair to say the Dartmouth product has been pretty good at that until this season. He doesn't have a Gerrit Cole fastball, or a Tyler Glasnow curve, but he does have a lot of intelligence, and sports fans tend to forget a smart athlete's ability to get the job done.