Robbie Ray is Back

Robbie Ray. He's always been an intriguing player to me. Coming up he was rather under the radar as a prospect, but after a few seasons in the minors, he made it to the big leagues in 2014 with the Detroit Tigers, and debuted with the Arizona Diamondbacks the following season. Although average at best in his first couple seasons with Arizona, he figured it out come 2017 with a 2.89 ERA, 3.72 FIP, and 12.11 strikeouts per 9 innings. He was a huge part in getting the Dbacks to the playoffs in an unbelievable turnaround season. Unfortunately that success was short lived, and a huge problem arose: walks. While most other stats remained constant, Ray's walks per nine was 5.09 in 2018, 4.34 in 2019, and an astonishing 7.84 in 2020. So what's happened so far in 2021?

Surprisingly, Ray has 2.25 walks per nine in 2021, a stark contrast from his past few seasons. This can be linked to his pitch usage this season compared to last. In 2020, Ray threw his 4-seam fastball 47% of the time, and his slider 31% of the time, whereas this season, he's thrown his 4-seamer 58% of the time, and slider only 23% of the time. He's spotting up his fastball and throwing it with more confidence, which enables him to pound the strike zone with more frequency. Additionally, 2020 brought about an anomaly in Ray's career. His fastball spin rate last year was in the 80th percentile in all of baseball. Never in his career has he even eclipsed the 61st percentile (apart from 2015 when he was in the 71st). Even more interesting, in 2019 his fastball spin rate was in the 47th percentile, and in 2021 it has been in the 44th. Essentially, he bounced up in spin rate in 2020 and went back down in 2021. My guess is Ray noticed the success of other pitchers in the new age of spin rates and he decided to follow in their footsteps. However, it backfired and gave Ray his highest walk rate of his career, so for 2021 he went back to what he's been used to and he's benefited heavily.

With any claim that a player is back to full form, however, never comes without potential concern. While holding a 3.81 ERA this season, his xERA of 4.57 suggests some form of regression. Yet, his FIP tells us the opposite story, with a FIP of 5.12 and an xFIP of 3.41. So which story do we trust? For the answer to that, we turn to my favorite stat: SIERA. I'm sure anyone reading this is familiar with the term, but even then the concept remains quite interesting to me. SIERA is on the same scale as ERA, but adjusts for what a pitcher is good at. For instance, if a ground ball pitcher keeps serving up ground balls to his infielders his SIERA will improve. While FIP is a fine stat, I find it limiting since it doesn't factor balls in play. SIERA finds a way to factor in balls in play, without hurting pitchers with subpar fielding behind them. The stat is also park adjusted, and it updates based on league averages (so since there's going to be about 500 no-hitters this season it's now harder for a pitcher to achieve a better SIERA).

Before I get too off-track, Robbie Ray holds a career-best 3.35 SIERA, even better than the incredible 2017 season he had (3.53), and over 2 runs better than 2020 (5.49). I would imagine his xERA is less than ideal due to his inability to limit hard-hit balls. Of the batted balls he's given up in 2021, 50% of them have been hit hard. But don't let that number alarm you--never in his career has he limited hard-hit balls well. In 2017 he gave up a hard-hit rate of 42%. And that's where SIERA comes in. No pitcher is good at everything, but SIERA tells us that Robbie Ray has been good in enough areas to succeed. It's true, he gives up a lot of hard-hit balls. But he's always been a strikeout-first pitcher, and this is his best season in terms of limiting walks. By pounding the zone with his fastball, he's sure to give up a fair-share of line drives, but in doing so he limits walks. And I think we'd much rather have a pitcher let hitters earn their way on than give up free bases.

All in all, I really like Robbie Ray going forward. He's shown a lot of promise this season, and is still 29 years old. The Blue Jays have certainly found a great member of the rotation for years to come. And arguably the biggest thing on Ray's side is that the Blue Jays don't need Ray to be incredible. Their rotation contains two other lefties in Hyun-Jin Ryu and Steven Matz, both of whom have been stellar this year, along with two young right-handers with promise in Alek Manoah and Nate Pearson (the latter being in triple-A currently. Should even two of these four guys pan out, the Jays have enough young talent to trade for a third and have their rotation set. Ray has all the pressure off of him, and simply provides Toronto with a surplus of promise from the starting pitching department. Watch out for this team, watch out for this under-appreciated rotation, and watch out for Robbie Ray.