Red Sox pitcher Brayan Bello pumps his fist after striking out Oakland’s JJ Bleday to end the top of the fourth inning on Tuesday night at Fenway Park. Bello got the first 10 outs via strikeout, but still had a rough outing. Charles Krupa/Associated Press

BOSTON — Like everything about his 2024 season, Brayan Bello’s start Tuesday was all over the place.

At times, Bello was dominant. Every one of the first 10 outs he recorded against the Oakland A’s came via strikeout, a Red Sox franchise high since at least the start of the expansion era (1961). That feat has been achieved by only two others in that span: Philadelphia’s Aaron Nola in 2021 and Andrew Heaney of the Texas Rangers in 2023. At one point, Bello fanned five straight hitters and seven of nine.

“I feel really good about that,” Bello said of his strikeouts. “I worked really hard to get those results, so to see what I did today makes me feel good.”

But there was a flip side to the start. Bello was belted around for five runs on nine hits over 51/3 innings in a 12-9 Red Sox victory. He threw two wild pitches, and yielded some hard contact, too, including a three-run homer measured at 457 feet. Despite plenty of run support, Bello couldn’t get through six innings, needing 105 pitches and allowing 11 baserunners.

His first nine batters faced illustrated his up-and-down night: strikeout, single, run-scoring double, wild pitch, strikeout, RBI single, strikeout, single, wild pitch, strikeout, walk.

In short, it served as a perfect example for how Bello has pitched much of the season: at times dominant and nearly unhittable, but also, lacking control and command at times. For someone whose every recorded out came via strikeout into the fourth inning, the night ended with Bello’s ERA going upward: from 5.19 to 5.40.

“You look up and (see) the strikeouts, but they put some good swings (against him),” said Red Sox Manager Alex Cora. “Everything he left in the zone, they hit it hard. So, just got to keep working and be ready for (his next start) Sunday.”

When Bello was good, he was very, very good. And when he was bad, he was horrid.

“I think all and all, it was a good day for me,” said Bello. “Yeah, the runs (allowed) are one thing. But I think I gave our team a really good chance to win. It was good to get those strikeouts, so I think today was a positive.”

The Red Sox have tried almost everything to get Bello on track. At the end of the last homestand, they pushed his next start ahead by three days, giving him a bit of a mental break while also providing an opportunity to address his inability to throw pitches in the strike zone.

There’s little doubt about the quality of his stuff, as Tuesday’s strikeout total suggested. But too often, Bello finds himself behind in the count, forced to the throw the ball over the heart of the plate – with predictably poor results.

Bello did a better job filling up the strike zone Tuesday, which was an obvious improvement. But too often, the pitches in the zone were hammered. That’s where command comes into play – he was getting strikes, but not locating precisely where he wanted the pitches within the zone.

Still, Bello wouldn’t be dissuaded postgame. He expressed satisfaction with the outing and saw the start as a step forward. The start marked his second straight win and the team’s record when he starts is 10-6.

“I think the difference was, just what I’ve been saying since the beginning – my pitches have all felt good,” he said. “I just needed to really attack the zone, and I think today, I was attacking the zone and being more aggressive.”