Two Cubs of a Kind: Kyle Hendricks and Alec Mills

I enjoy an Aroldis Chapman fastball. But never will such enjoyment exceed that of watching a pitcher deceive, frustrate and toy with a hitter the way command and finesse pitchers do. The cohort of such pitchers isn’t quite an exclusive club, but it’s not nearly as populous as it once was. The Chicago Cubs have collected two of the game’s most prominent finesse pitch commanding pitchers: Kyle Hendricks and Alec Mills. 

Earlier this week, Kyle Hendricks painted a Picasso of an outing: A nine-inning, walk free, three-hit shutout. In 103 pitches Hendricks dominated the Reds, striking out nine. He induced twice as many ground balls as he did flyballs. Hitters averaged a 0.8-degree launch angle and 83 mile per hour exit velocity, generating a .143 xwOBA across the outing. It doesn’t get much better than that.

The greener Mills in his first start of 2020 pitched an impressive six innings (after, arguably, being removed prematurely) to the tune of two walks and two hits. Both hits authored by Nick Castellanos, and one being a round-tripper, Mills only made one mistake. Of 17 batted balls, only three had an expected batting average over .500 – of which two were converted into outs.

In an age when velocity is king, watching these pitchers overwhelm hitters with underpowering velocity is one of the most engaging in today’s game. But what allows them, specifically these two Cubs hurlers, to eat through a lineup so effectively?

Similar to their arsenals, their success is rooted in the possession of a wildly diverse set of skills, none of which are blunt. They keep the ball on the ground and allow consistently weak contact. In addition to having well-rounded arsenals, the pair’s ability to command those pitches is what allows for damageless contact.

Cred. Brad Mills/USA TODAY Sports

Firstly, the batted balls Hendricks and Mills allow are innocent. Hendricks found himself in the 94th percentile in exit velocity and 87th in hard-hit rate in 2019. Even if hitters were finding a way to make hard contact, his barrel rate, sitting at the 81st percentile, limited the impact those batted balls had. This ability to suppress dangerous contact produced a strong .304 wOBA last year (23 points below league average).

Alec Mills has shown similar potential. After logging more time on the bump in 2019 and having a more successful campaign one year prior, we’ll look at both seasons to get an idea of where he intersects with Hendricks. He didn’t achieve quite the same level of prosperity that Kyle did in 2019, surrendering an average 88.4 MPH exit velocity and 7.6 barrel rate. Those numbers aren’t very exciting and his xwOBA, .337, confirms that. 2018 was a much more productive season. His barrel rate, 4.9%, would have ranked 78th had he been one of 355 qualifiers, and his xwOBA was .256, a would-be ranking of 8th, one point better than Cy Young winner Jacob deGrom.

Both pitchers just don’t allow their batted balls to fall for hits. Again, the excessive contact they do allow – a normally threatening rate – is all innocent. Mills hasn’t shown complete control of this concept yet, especially when compared to Hendricks. But he has shown significant promise, especially in 2018. He should eventually develop into something close to Kyle’s complete mastery of the concept. That mastery comes in the form of allowing a disproportionate number of hits per batted ball. Hendricks has done a tremendous job at staying far away from league average BABIP (never far from .300):

BABIPKyle HendricksAlec Mills

Kyle Hendricks used four pitches last year: a changeup, sinker, four-seam fastball and curve. Each of those pitches offers upside. In 2019, only his sinker sat a little above league average xwOBA. While most pitchers have at least one pitch they struggle to use effectively, all of Hendricks’ pitches are effective, giving him more tools. That’s why even his most seldom used pitch, his curveball, still accounted for nearly 10% of the pitches he threw last year. Hendricks is comfortable going to almost any of his pitches in any situation. That’s not something all pitchers can say.

2019, Kyle Hendricks:Pitch PercentagewOBAxwOBAWhiff Rate:
Four Seamer20.5.223.32827.4

Hendricks isn’t a strikeout pitcher, but beyond his sinker, his primary offering, all his pitches boast very similar whiff rates. This indicates that Kyle does such a good job of mixing his pitches that he generates as many swings and misses with mental games as he does with his pitches’ actual attributes.

The location of those pitches is also skillful. Each pitch is placed in a very specific, intentional area. Particularly, the changeup and four-seamer, both of which are thrown outside the strikezone as often as they are inside. Call it uncontrolled but for a batter it’s unpredictable. His sinker also has a presence throughout the strike zone allowing him to get ahead in the count in a variety of ways.

His curveball’s location is also intriguing. While most pitchers use their curveballs to get whiffs, Hendricks uses his as a strike pitch. It consumes the entire bottom two-thirds of the zone. A breaking pitch low in the zone is difficult to square up, but it’s also dangerous. If he hangs a pitch, his opponent has a chance to do serious damage. But Kyle’s success with the curveball in a potentially dangerous place highlights just how finely tuned and consistent he is.

Going back to Alec Mills we have another arm that has a collection of strong pitches. Mills’ four-seam fastball, sinker, changeup, curveball and slider make up his five-pitch arsenal. Using two seasons to evaluate Mills makes things a bit complicated, especially with the contrast between the two. 2018, despite a small sample size, was Alec’s best season. After that, 2019 was especially rough. Regardless, there’s still value to extract from both years.

In 2018, his best pitches were his sinker and changeup, posting a .207 and .153 xwOBA respectively. His changeup was an impressive weapon gathering a ton of fruitless swings – a 48.4% whiff rate and 37% putaway rate. However, hitters roughed up Mills’ fastball for a 92.8 MPH exit velocity and .380 xwOBA. This was where the majority of the damage was done to Mills in 2018.

(Photo by Nuccio DiNuzzo/Getty Images)
Cred. Nuccio DiNuzzo/Getty Images

Come 2019, with little change to his struggling fastball and regression on his previously elite changeup Alec got hit harder. Changeups in the zone were swung at 10% more, and such pitches were hit into play 7% more. Batters were hitting the changeup more than 20 MPH harder. Now, in 2020, his changeup may be back in shape after recording five outs with it in his Tuesday start including one strikeout.

One major change Mills made in 2019 was his curveball grip. In multiple stents in AAA Iowa, he spent time refining his curveball intending to add some separation between it and his slider. In 2018, the two pitches’ velocities just eclipsed at their tails. A year later after shaving nearly five miles per hour off the pitch Mills’ curveball velocity sat well below his slider velocity, and over 10 miles per hour below the league average curveball making it unconditionally the slowest major league curveball. His new curve offered great results in 2019. It’s difficult to compare it to the 2018 rendition, as he only threw 23, but ignoring that, he added 36% to his whiff rate, 12% to his chase rate, generating a 66.7% miss rate on chased pitches.

All this finally gave Alec five true, distinct pitches. This allowed him to diversify his offerings. You can see what that extra pitch does for him below. He implemented it as he worked deeper into counts both ahead and behind (Note two-strike and three-ball counts). This adds a layer of unpredictability – just like Kyle Hendricks’ four plus pitches.



Some of the variation between 2018 and 2019 for Alec comes from his pitch locations. Most notably, Mills’ changeup bled too much into the zone in 2019. He gets great vertical movement on the pitch – 11% more than league average in 2018, 13% more in 2019 – and he should use it. Allowing it to float out of the zone will generate more swings and weak contact, especially ground balls. Also, Alec’s four-seam fastball was effectively used throughout the strikezone in 2018, compared to 2019 when it remained tethered away to a righty. With a more concentrated spot, the pitch becomes more predictable. If a batter is sitting fastball, they now have a better idea where they’ll see it. This is exactly how Kyle Hendricks uses his sinker (his most used pitch), as previously mentioned.


Alec Mills, 2018:


Alec Mills, 2019:

Kyle Hendricks and Alec Mills are two very exciting pitchers. They’re exciting because so much of what makes them great contrasts from what makes others effective. It’s different and it’s fun. As Hendricks plays in his seventh and age 30 season he’s sure to pass on some wisdom to his less-experienced teammate, Alec Mills, who looks to follow in Kyle’s footsteps and develop a similarly productive profile.

All data sourced from, and