What's the Deal with Matt Magill?

Magill was a late selection of the Los Angeles Dodgers (Round 31, pick 15) in the 2008 June Amateur Draft out of Royal HS. Magill’s high school scouting report has pretty typical of a high school pitching prospect:

"Magill has a tall, projectable frame. His fastball sit in the 88-90 mph range, but it’s straight and hittable when left up in the zone. He’ll need to develop sink and movement to succeed with his fastball at higher levels." (Courtesy of Baseball America).

After being drafted, Magill progressed steadily through the Dodgers organization, being groomed as a starter. His minor league success peaked with his 2012 season at AA Chattanooga. That season, he put up a 3.45 ERA in 146+ IP, while striking out 168. Magill made his major league debut with the Dodgers in 2013, with a disastrous six game stretch which produced a 6.51 ERA and a BB/9 of 9.11. Magill bounced around at various levels of the minor leagues in the years following, making brief major league stops with Cincinnati and spending time in the Padres organization. Magill began the 2018 season as a 28-year-old at AAA Rochester, before getting the call to Minnesota in late April.

Magill is off to a strong start as a Twin. Through 23.2 IP (as of Wednesday night) he has produced the following:

Magill has a strange set of numbers to examine. He doesn’t fit a particular mold. He’s no longer producing the high strikeout numbers he did as a prospect early in his career. He also has a low ground ball rate of just 36%. Magill is 10th in BB/9 among major league relievers who have thrown at least 20 innings and has the 15th lowest BaBIP of pitchers in MLB. Finally, he has stranded 98.9% of runners on base, a figure tied for the major league lead with recently traded former Royals closer Kelvin Herrera. Magill’s BaBIP and LOB% seem unsustainable, but his SIERA is indicative that he has produced consistently strong performances for the Twins.

SIERA (skill-interactive ERA) is a development from FIP and xFIP which attempts to weight the various reasons pitchers are successful or unsuccessful. Magill’s 2018 SIERA is 3.67, a figure that lands him in between the range of above average (3.75) and great (3.25) according to FanGraphs. So what does Magill do on the mound and how has he established some MLB stability after struggling to do so previously in his career?

Magill has a difficult pitch mix to evaluate, because his major league sample is so small it’s still developing. Magill can throw a four-seam fastball, sinker, cutter, curveball, slider and changeup. He predominantly uses his four-seam, slider, and cutter, with an occasional changeup mixed in. Remember Magill’s big, projectable frame? The move from starter to reliever has allowed him to add a little extra to his fastball, his average velocity when he first reached the majors in 2013 sat between 90-92 mph, in 2018, it has averaged 95 mph.

The final development Magill has made which has contributed to his success, is the development of his cutter. In Magill’s previous stints in the major, he threw his cutter between 6-11% of the time. In the last few months with Minnesota, he has used it roughly 22% of the time. Magill’s cutter has heavy sink and sweep to it. Consider this, between Magill’s fastball (with much more refined control) and his cutter, Magill allowed an opposing wRC+ of 185 in 2013, 285 in 2016, and just 45 in 2018. Magill might be due for some regression in the near future, but why Molitor refuses to spread the work load and ease the burden on Addison Reed, Ryan Pressly, and Trevor Hildenberger is a mystery.