Andrew Miller Changed But No One Noticed

Baseballs are flying out of ballparks. The nerdiest, smartest baseball minds in the world are repeatedly demonstrating the value of the fly ball, much to the dismay of the iconic Lou Brown and every Little League coach you ever had, both of whom implored their pupils to “hit the ball on the ground.” When glancing at Andrew Miller’s batted ball profile from 2017, you might notice something disastrous. As a reliever, he’s never allowed more fly balls and line drives and he’s never induced fewer ground balls. The Indians need him to be as good as ever in 2018, especially considering the departure of Terry Francona’s bullpen engine, Bryan Shaw. Time to panic, right? In the words of the almighty Lee Corso, “not so fast, my friend.”

With the mid-90’s fastball setting up the sweepiest of sweeping sliders, it’s easy to get lost in the whiffs. There’s more to unpack with any pitcher, however. Even the best of the best strikeout arms in the game, including Miller, still have around 60 percent of the plate appearances against them result in a ball being put in play. The type of contact allowed and the contact authority allowed make up how successful they will be in that other 60 percent.

Courtesy of Fangraphs

On the surface, Miller’s increased fly ball and line drive percentages coupled with decreased ground ball percentages offer a murky outlook. Those three tools all moving in the wrong direction at the age of 32 could be major red flags, without more information. They depict a story about the type of contact he allowed, which is only half of the ball in play battle.

Courtesy of Baseball Savant

The other half of the ball in play battle, contact authority allowed, paints an entirely different picture. Instead of suppressing balls hit in the air, Miller mitigated contact. Miller’s 2015 and 2016 campaigns featured an average exit velocity against of around 87 miles per hour. In 2017, that number dipped to 81.3 miles per hour. Opponents, on average, hit the ball about seven percent softer against Miller. It may not seem like a substantial drop, but the effect it has on expected results is clear.

In 2017, MLB hitters sported a wOBA of 0.455 on balls hit 81-82 miles per hour, versus a wOBA of 0.570 on balls hit 86-87 miles per hour. So, Miller’s contact mitigation yielded about 20 percent better results on the wOBA spectrum. For the sabermetrically averse, allowing consistently softer contact led to less damaging outputs against the left-handed reliever.

Putting it all together requires weighing the negative effects of a more inherently damaging batted ball profile against the positive effects of less inherently damaging contact authority. A quick glance at his ERA and FIP show that, despite about one fewer strikeout per nine innings, Miller was as effective as he has ever been in 2017. Delving deeper, one will find that he posted his lowest wOBA allowed of his relief career, by a hair.

Courtesy of Baseball Savant

The first takeaway is that Miller’s profile shifted drastically in many directions, but amounted to approximately the same really, really, obscenely good pitcher in 2017. Understanding why the shift changed is a tad more difficult. A noticeable trend can be identified in pitch velocity, with his fastball and slider each seeing about a one mile per hour decrease.

Courtesy of Brooks Baseball

A simple explanation for this drop-off could be age. Relievers tend to lose a little off their fastball more quickly than starters. Looking back at what transpired prior to the 2017 season is important for contextual purposes, however. During Spring Training of that year, he made a comment to a reporter about his physical state after Game 7 of the 2016 World Series.

“Total body, physically – I was done,” he recalled. “I just lay down there on the floor.”

A couple weeks after that comment, he jumped right into the World Baseball Classic to help Team USA. After being Terry Francona’s workhorse from early October into the first days of November, sometimes hurling 40-to-50 pitchers every other day, Miller pitched competitively in early March. Having only four months of offseason to recuperate could explain a slight velocity drop and perhaps offers an even better explanation for it than being a few months older.

Of all pitchers with at least 150 batted ball events, Miller led the MLB in exit velocity against, despite a fleeting offseason, aches and pains throughout the season, and allowing hitters to elevate more often. Though he would rather have it the other way, a quick playoff exit provided him with a much-needed respite. If he can regain 2016 form because of it and maintain the contact mitigation boon, look out. After seeing how badly hitters against the different Millers of 2016 and 2017, a combined version of the two would leave them praying for a pinch hitter.