Brayan Bello’s Changeup Places Him Among Promising Young MLB Starters

The Boston Red Sox have really struggled to develop starting pitching in recent years. You really have to go back to Jon Lester to find a true homegrown ace. Chris Sale obviously had his best years in Chicago, Eduardo Rodriguez cut his teeth in the Oriole system, and literally every true ace the Sox have had since Roger Clemens – from Pedro Martinez to Derek Lowe to Curt Schilling to Tim Wakefield to Josh Beckett – got his start elsewhere.

Now, along comes Brayan Bello to perhaps change that narrative. Each year, I compile an ordered list of top minor league pitching prospects based on performance and age relative to league and level. Bello qualified for my list in each of his three full-season minor league seasons, ranking #194 in 2019, #47 in 2021 and #29 in 2022. It’s no small feat for a pitcher to have made such a big jump from 2019 to 2021, considering that 2020 was totally lost to the COVID-19 pandemic for minor league players.

Bello showed flashes of promise in 57 1/3 major league innings last season, but on the whole was unsuccessful, posting a 2-8, 4.71, mark. That’s no big deal, however – the big leagues are full of hurlers who performed comparably in their first opportunity.

To say the least, he’s been much better this time around, going 4-4, 3.49, in his first 11 starts this season. He’s been at his best of late, and has been particularly strong against the hated Yankees, which hasn’t gone unnoticed among Sox fans.

Whether you’re watching him in person or on TV or perusing his detailed pitch-by-pitch statistics, Bello’s changeup stands out as his best pitch. Each season I grade out the pitch arsenals of all starters throwing 135 or more innings based on their bat-missing and contact management performance relative to the league and assign all qualifying pitches letter grades.

Thus far in 2023, Bello’s changeup has posted a 25.0% whiff rate and a pitch-specific 73 Adjusted Contact Score. That whiff rate is over two full standard deviations better than average, while the contact management number is over a half-standard deviation better. He earns an “A+” for the pitch. Only Tyler Anderson (as a Dodger) fared better with his changeup last season.

How is the rest of his repertoire performing? Not nearly as well.

His two most oft-used pitches are his sinker and four-seam fastballs, which he throws a combined 57.5% of the time. Both check in as average “B” grade pitches, which to be honest is quite acceptable for a young (Bello is 24) pitcher. The sinker is almost exactly average at both missing bats (6.3%) and managing contact (96 Adjusted Contact Score) while the four-seamer misses plenty of bats (11.1%) while allowing quite a bit of loud contact (128).

Bello’s problem pitch has been his slider, which he has thrown 21.0% of the time. It has performed quite poorly by any measure (5.6% whiff rate, 120 Adjusted Contact Score), earning an underwhelming “D” grade to date. Bear in mind that this is his only true breaking pitch – how many truly good pitchers lack a useable breaking ball?

But back to the changeup. He only throws it 21.4% of the time, almost exactly as much as he throws his subpar slider, and less than he throws either of his fastballs. Sure, you have to be careful not to overuse your changeup, lest it cease to be a change of pace, but man, Bello sure could benefit from at least some increase in its usage.

But remember, it was Tyler Anderson who just last year got even better results from his change. This season, Anderson’s fastball has gone backwards, and his changeup has suffered significantly as a result. A great changeup is an asset, but it needs help from the rest of a pitcher’s repertoire.

All in all, Bello has a chance to be an exceptional pitcher in the future, but expectations may have gotten a bit ahead of him at present. Yes, he is one of the foremost grounder generators in the game (58.2% grounder rate), but like Marcus Stroman and Framber Valdez, allows fairly authoritative contact overall. His overall (89.7 mph), fly ball (91.8 mph) and grounder (87.5 mph) average exit speeds allowed are about a standard deviation higher than average. On the other hand, his average liner exit speed allowed (92.9 mph) is over a half standard deviation lower than average.

Thus far in 2023, Bello has a bit fortunate on all batted ball types (117 vs. 139 Unadjusted vs. Adjusted Fly Ball, 90 vs. 92 Line Drive and 94 vs. 108 Ground Ball Contact Scores) – his 102 overall Adjusted Contact Score is comfortably above his unadjusted 91 mark. Despite an unsustainably low 13.6% liner rate allowed, he has been a slightly below average contact manager to date. None of his pitches induce many pop ups; he needs a pitch to get some outs up in the zone. With K (22.2%) and BB (7.8%) rates both in the average range, this gives him a “Tru” ERA- of 99, worse than both his 79 ERA- and 95 FIP-.

I still believe Brayan Bello has a bright future ahead of him, but he has work to do. He needs to develop a viable, league average range breaking ball and tweak his pitch usage to approach his potential. That said, possession of a true go-to out pitch gives him a heck of a head start, giving him a weapon against opposite-handed hitters – mastery of whom represents the hardest part of an MLB starting pitcher’s job.