Cubs Were Right to Buy Low On Shelby Miller’s Evolution – Cubs

A few days after pitchers and catchers reported to camp, the Chicago Cubs agreed to a multi-year contract with right-handed pitcher Shelby Miller. This will be Miller’s second stint with the Cubs organization, though it will undoubtedly be longer than his cup of coffee with the team in 2021 where he totaled just two innings. Miller has reinvented himself between now, then, and when he (eventually) takes the mound at Wrigley again. 

Miller was forced to change after 2022. Between 2016 and that season, the former first-round pick battled injuries and ineffectiveness and had been dropped from MLB rotations as a whole. Facing a future where it appeared he would only be MLB depth, toiling away in Triple-A, the hurler underwent some changes in arsenal and arm slot. 

When the Cubs last saw Miller in their organization, he threw more overhand and featured a fastball-sweeper mix with some cutters thrown in for good measure. His four-seam fastball sat a touch under 94 mph, which was fine for the time, but not a particularly overpowering offering. He struggled to strike hitters out with a K-rate under 13%, and was knocked around to the tune of an ERA over nine during the 2021 season. But that was then, and this is now.

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The Cubs are hoping that they’re signing a version that looks much more like the guy Miller turned into during the 2023 season and beyond. Featuring an arm angle that has dipped over six degrees, Miller is a different beast. The velocity has ticked up, now sitting over 95mph. Coupled with the lower arm slot, the pitch now features more arm-side run. Combined with his new fastball shape is a fun little split-finger that has become the bane of hitters’ existences: last year, it sported a batting average against of just .135. Hitters are no longer teeing off Miller; now, they’re striking out at a 29% rate (at least, they did in 2025). 

The reason he has increased his effectiveness is in how these two pitches play off of each other. They have similar induced spin patterns, but offer distinct observed motion (pictured above). This is due to seam-shifted wake, essentially, playing with the grip of the baseball to create added deception. They also work well in terms of location; Miller throws the fastball up while the split finger falls off the table (pictured below).

These two pitches make life incredibly difficult for hitters, much more so than Miller’s fastball-sweeper combination. Those pitches offered enough distinction on plane for hitters to easily determine what was coming. Now, with seam-shifted wake characteristics creating deception in spin, as well as the pitches working in tandem on the same vertical plane, Miller seems to have finally found the best version of himself. 

The split-finger is also an important weapon in attacking opposite-handed hitters. The 35-year-old limited left-handed batters to a .233 wOBA last year and just a .139 batting average against. Over his career, Miller has struggled against LHH, so adding a pitch designed specifically to get those kinds of hitters outs helped create such impressive splits. In many ways, Miller has turned into a better version of what Mark Leiter Jr. was with the Cubs — a right-handed pitcher who is particularly useful against lefties.

If you’re asking yourself “How did the Cubs find such a useful reliever this late into the offseason?”, the answer is because Shelby Miller is slated to miss most, if not all, of the upcoming season due to Tommy John surgery. Because this is a multi-year contract, this is less of a signing for 2026, but an upside play for 2027. This will allow the Cubs to monitor the rehab process and bring him along within the organization. If it works out, this deal ensures they have a useful bullpen option heading into next year. There’s certainly a chance that when he does return to the mound that he’s a shell of himself, but with how far TJ-surgery recovery has come, there’s a good chance he’ll be able to bounce back just fine. 

This might not change the outlook of the 2026 season, but represents a smart flier for the future. 

How do you grade the Shelby Miller addition? Are you excited? Do you think this will work out for the Cubs? Let us know in the comments below!