The Incredible Odyssey and Recent Reinvention of Robert Stock

Did you miss Robert Stock? Your answer might depend on how much of the lost season of 2020 you blocked out. The Red Sox went 24-36 and finished dead last in the AL East, and in all likelihood less you remember about it, the better off you are. Here comes a reminder anyway. On Tuesday, Chris Cotillo of MassLive reported that the Red Sox and the 35-year-old right-hander have agreed to a minor-league deal that includes an invitation to spring training. Matt Corr broke the deal down for us on Wednesday, but Stock’s odyssey is fascinating enough that it deserves a full retelling. Most recently, Stock pitched for the Naranjeros de Hermosillo of the Mexican winter league, with whom he won the pitching Triple Crown: leading the league with 10 wins, 78 strikeouts, and a 1.60 ERA over 14 starts and 84 1/3 innings. Those kinds of numbers tend to turn some heads, and on January 10, the team announced that he would be missing the semifinals against Jalisco in order to undergo a physical with the Sox. (Their announcement also expressed some hope that he would return after the physical; if the Naranjeros make it past Jalisco, it would be really fun if the Red Sox actually let him pitch in the finals.)

Stock has had a long journey. He started as a two-way player, a right-handed pitcher and left-handed-hitting catcher. During his teen years, Baseball America three times named him the best player in the country for his age. He enrolled a year early at USC at age 16 in order to become draft eligible at age 19, and the Cardinals selected him in the second round of the draft in 2009.

Stock started his professional career as a catcher, but switched to pitching after running a .644 OPS in Single A in 2011. Stock bounced from the Cardinals to the Astros to the Pirates to the Reds, and his long road to the majors culminated in 2018, when he debuted with the Padres. Stock ran a 2.50 ERA and 2.71 FIP over 32 relief appearances and struck out just under a batter an inning. Despite a worrisome walk rate, it looked like he had finally made it. He had not.

Stock made just 10 appearances with the Padres in 2019, running a gruesome 10.13 ERA in the majors and a 3.86 ERA in Triple A. The Phillies picked him up on waivers after the season, then waived him again in July. He spent the short 2020 as a low-leverage relief arm with the Red Sox. Over 10 appearances and 13 1/3 innings, he ran a 4.73 ERA despite a 3.34 FIP. Stock pitched briefly for the Cubs and Mets in 2021, running an 8.00 ERA, with (somehow) even worse peripherals. He spent 2022 with the Doosan Bears of the KBO, and things started to change.

Stock pitched only as a starter in Korea, running a 3.60 ERA and a 4.02 over 29 starts. Despite walking an alarming 4.5 batters per nine innings, the performance earned him a minor-league deal with the Brewers. However, pitching mostly out of the bullpen, he struggled to an 8.22 ERA in triple-A Nashville, and by June, he was pitching for the Long Island Ducks of the independent Atlantic League. Once again a starter, Stock went 9-4 with a 4.40 ERA in Long Island, and even threw a no-hitter.

Stock signed with the Tecolotes de los Dos Laredos of the Mexican League, going 9-4 and running a 3.38 ERA over 19 starts and 98 2/3 innings. Along with his electric winter ball performance, that was enough to earn him yet another chance.

During his time in the majors, Stock was known for walks, a four-seam fastball that could touch 100 mph, and not much else. Stock also had major issues both hitting the strike zone and inducing chases, resulting in a disastrous 23.1% walk rate. On the other hand, his career groundball rate is a beautiful 49.8%, and during his year in Korea, FanGraphs credits him with an absurd 69.6%. That would certainly make him a good fit for Fenway Park, but I wouldn’t be so sure that the Red Sox are getting the same Robert Stock you might remember. Here he is pitching in Mexico, now a full-on side-armer.

A  recent clip on Stock's YouTube channel includes his velocity and movement profile, highlighting a 95 mph sinker with 18 inches of arm-side run and a sweeper with 20 inches of glove-side break. Needless to say, he never exhibited stuff that looked anything like that back during the Red Sox. After 14 years as a professional, Stock has reinvented himself into an East-West pitcher, a classic sinker-slider guy rather than a flamethrower. It’s not hard to see why the Red Sox might think they can make that package work, presumably out of the bullpen once again. Stock's is a story of incredible perserverance, and just getting this chance is a huge accomplishment. That said, even during his extremely successful time in Mexico, he still walked nearly four batters per nine innings. If Stock is going to find his way to Boston, he has to find a way – for the first time in a pitching career that is now 13 years old – to cut down on the walks.