Brayan Bello
July 17, 2025
Starting Pitcher
Boston Red Sox
Overview
When the Red Sox signed Brayan Bello to a 6-year $55 million extension after just his second big-league season, they made it clear they saw him as a foundational piece in the rotation. Through the first 3 seasons of his career, Bello has flashed great potential but has struggled with consistency. Now in year 4, Bello has found a groove going into the break. 2025 has been a tale of two halves.
April-May:
8 appearances, 40.0 IP, 3.83 ERA, 1.63 WHIP, .281 BAA, 4.95 BB/9
June-July:
8 appearances, 51.2 IP, 2.61 ERA, 1.01 WHIP, .212 BAA, 2.09 BB/9
What stands out the most to me is how aggressive Bello has been attacking hitters recently. A significant shift in pitch mix, including the addition of a cutter, has aided in this approach. An approach that contrasts with the broader pitching philosophy the organization has leaned into over the last 2 seasons.
Pitch Mix and Being Aggressive
When Andrew Bailey was hired as the Red Sox pitching coach at the conclusion of the 2023 season he brought with him a unique philosophy. Emphasizing movement over velocity, Bailey has encouraged his pitchers to lean on secondary pitches and prioritize deception. From 2023 to 2024, the percentage of fastballs thrown by Sox starters dropped almost 10%, going from 58.6% to 49.4%.
The evolution of Bello’s arsenal is shown below.
In 2023, fastballs made up 58% of Bello’s arsenal. When Bailey entered the door in 2024, that dropped down to 45%. But in 2025, that percentage has risen again, up to 64%.
In 2024, it wasn’t until July when Bello decided to throw his four-seamer again, not throwing a single one in his first 14 starts of the season. Through those 14 starts, Bello held a 5.55 ERA, 1.47 WHIP, and a .270 BAA. In the final 16 starts of the season with the four-seam in the mix, he put up a 3.66 ERA, 1.27 WHIP, and a .238 BAA. Before bringing back the four-seam, Bello was a 3-pitch pitcher. A sweeper, paired with a sinker and changeup that displayed roughly the same movement patterns.
This approach didn’t challenge hitters enough. They only had to look for a sweeper and a sinker, just needing to sit back an extra half-second for the changeup. While this might not be a worry for a relief pitcher, a starter needs to be able to offer hitters, who they face up to 3 times each, multiple looks. The addition of the four-seam provided another look for hitters, especially when he played it up in the zone to counter his other pitches only breaking down and in/away. This opened up a new layer of unpredictability in his sequencing.
In 2025, I believe the cutter is creating a similar effect, providing another pitch movement to keep hitters and lineups off balance.
As previously stated, the last 8 appearances for Bello have been stellar. As of the All-Star Break, Bello holds career bests in ERA, BB/9, BAA, WHIP, opponent SLG, Hard-Hit%, and opponent wOBA. I touched on the evolution of his arsenal over the last few years, however the adjustments he has made within this season are especially telling.
April-May: Fastball: 55%, Breaking: 27%, Offspeed: 18%
June-July: Fastball: 71%, Breaking: 17%, Offspeed: 12%
Not only is he throwing more fastballs than at any other point in his career, he is pounding the zone. From June through July, Bello has thrown 52% of his pitches in the strike zone, up from 46% over the first 2 months of the season.
This aggressive mindset shows up most clearly in 2-strike counts. From April through May, Bello’s 2-strike pitch distribution was relatively balanced: 40% fastballs, 39% breaking balls, and 21% offspeed. However, starting in June, in counts where you would expect heavy breaking balls, these percentages have changed drastically. Fastballs are up to 68%, dropping breaking balls down to 20%, and changeups to 12%.
By challenging hitters in the zone, opponents have started to chase outside of it, increasing his chase rate from 22% to 30%. This has also led to softer contact, with his hard-hit % falling from 41% to 32%.
I believe a difference maker for Bello going forward will be his changeup, which has been his best pitch, ranking 1st among his repertoire in putaway % each season of his career.
Bello’s start vs Colorado on July 8th was arguably the best of his career, throwing a complete 9 innings, giving up 5 hits, 2 runs (both coming on a 9th inning 2-run HR) and striking out 10 with only 1 walk. Bello stated postgame,
“My changeup was very good today,” he said. “I feel like I have the feeling back for my changeup. I’m able to command it and also throw it whenever I want. For me to have that extra weapon is very good.”
The last sentence sums up my point. If Bello can continue to stay on the attack with the mixture of fastball looks (four-seam, cutter, sinker) and maintain command of his exceptional changeup, he has the tools to be the reliable number 3 starter that Boston needs.
