This story was excerpted from Ian Browne’s Red Sox Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

The early-season star of the Red Sox’s new-and-improved starting-pitching factory? Kutter Crawford.

At 27 years old, the homegrown righty -- Boston's 16th-round selection in the 2017 Draft -- is pitching the best baseball of his career. And he's not just leading the Red Sox. Crawford's 0.66 ERA through his first five starts this season is tops in MLB.

His ERA through five starts is tied with Roger Clemens (1991) for third best in club history, trailing Hall of Famer Lefty Grove (0.21 in '36) and Red Sox Hall of Famer Dave “Boo” Ferriss (0.60 in '45).

Crawford hasn’t allowed a home run in 43 2/3 innings dating back to last season. He has given up just two extra-base hits this year. While nobody could have predicted Crawford would get off to a start this dominant, he has been building towards this.

Crawford has a five-pitch repertoire that is led, fittingly, by his cutter. He also utilizes a four-seamer, sweeper, splitter and knuckle curve.

His emergence this season is due to a multitude of factors. Here are a few: Improved strength and conditioning in the offseason that has allowed him to gain stamina with pitches and increase his pitch count; increased aggressiveness with pounding the zone; and, of course, the Andrew Bailey effect.

Boston’s new pitching coach is clearly getting the most out of his staff, which explains why the Red Sox are 13-10 despite dealing with a barrage of injuries.

In truth, though, a lot of what is happening with Crawford is progression through the experiences he’s gained.

“I think a lot of it is just kind of like, the thoughts [throughout the game],” Crawford said. “Having that confidence as the game goes on and your body starts getting a little more fatigued and all that, and just reassuring that I’m pounding the zone. Don’t try to start nibbling around the edges, because that’s when you get hurt.”

It has also helped Crawford that the Red Sox have defined his role after using him in both relief and starting in 2022 and '23.

“I always trusted him since Day 1 when I saw him,” said Red Sox manager Alex Cora. “I knew his stuff was really good. When he made the team [two] years ago, we made him a reliever. We made him a two-pitch pitcher -- that was wrong from our end. This guy is a starter at the big league level. He’s got weapons. We’re going to let him pitch. He’s learning throughout the process, and we’re very proud of him.”

Crawford endured some lumps in 2022 (3-6, 5.47 ERA), when he suffered a right shoulder impingement that ended his season a month early as the Red Sox dealt with several injuries to the rotation. He had to learn on a trial-by-fire basis, but that's paying off now.

“2022 was a big learning year,” Crawford said. “Kind of taking what I learned from then to now, throwing strikes is huge -- trusting your stuff and having conviction in your pitches makes a huge difference.”

While it was a setback for Crawford at the time, Cora notes the pitcher used that time to his advantage.

“I think he learned a lot toward the end of the season in '22 when he got hurt, staying in the dugout, talking to guys, talking pitching,” said Cora. “He has a good feel and he has good stuff.”