Daniel Bard hasn’t allowed a run since May 23, a stretch of 19 1/3 innings in which his ERA has plummeted from 3.60 to 2.05. The Red Sox are 4-0 in Andrew Miller’s four starts this year, and Miller himself is 3-0 with a 3.57 ERA.

This isn’t the first time Bard and Miller have played together. They were teammates at the University of North Carolina, two years ahead of Portland Sea Dog catcher Tim Federowicz. And Federowicz, who was a freshman at UNC when the two pitchers were juniors who were on the cusp of being drafted in the first round of the 2006 draft, said their powerful arms were evident even then.

“[Bard] and Andrew hit top 90s quite a few times,” Federowicz said before Portland’s game against the New Hampshire Fisher Cats on Saturday. “Both of them in college, you could tell how uncomfortable guys were in the box every time they would throw the ball.”

While Miller (who will start the Sox’ first game of the second half on Friday against Tampa Bay) and Bard may have overpowered ACC hitters – Miller set UNC records in single-season and career strikeouts, and Bard was named ACC Freshman of the Year in 2004 and ACC pitcher of the week twice in 2006 – Federowicz said it is their command that has led to their big-league success.

“Anybody can hit a fastball in the upper 90s if you leave it over the middle of the plate,” Federowicz said. “Daniel, I think his big thing is his command, his command of his fastball. I mean, guys go up there knowing they’re going to get the fastball, but they’re still waiting for a pitch that they can hit, and he just never really gives them a pitch they can hit.”

Federowicz added that Bard only runs into trouble when he loses command and leaves his fastballs up in the zone and over the plate.

“It doesn’t matter if you’re throwing 9 mph or 98,” the catcher suggested. “If you leave it over the plate, yeah, guys are going to miss a little bit more with Daniel and Andrew, but you leave it over the middle of the plate, their guys are going to hit it anyways.”

Miller, Federowicz said, had the command back in college that Bard now has, with “unreal” movement on his fastball.

“He would just start that fastball middle and it would end up on the outside corner like it was nothing,” Federowicz recalled. He added that Miller’s throwing motion across his body made him “a little bit more deceiving to the hitters and a lot harder for them to time him up.”

To stay in the big leagues, he added, Miller will need to sustain that command.

“He wants to keep the walk numbers down, and of course with that the strikeout numbers will go up,” the catcher suggested. “Guys aren’t comfortable in the box, and a lot of their approaches are, ‘Take, take, take.’ … Well, if he doesn’t walk you, and he doesn’t throw balls, then it’s going to be hard to take, take, take. They’re going to have to start swinging, and that’s when it gets tough on them, and they won’t be able to square him up. That’s going to work for him a lot. He’s going to be very successful if he does that.”

Federowicz said that good off-speed pitches are necessary to keep opposing hitters from sitting on fastballs, and that both Bard and Miller have strong off-speed stuff, especially sliders, making them more effective major league pitchers.

After a dominating college career, Miller struggled in his first five years in the pro ranks from 2006-10 while with the Tigers and then Marlins. Federowicz suggested that the influence of a Red Sox player development system that has yielded top pitchers such as Bard, Jon Lester and Clay Buchholz has been significant.

“He’s with a winning program right now. He’s with a winning organization that most likely will be in the World Series this year, knock on wood,” said Federowicz. “I think he’s happy where he is, and as long as they keep winning, everyone’s going to be happy with his pitching.”

Should Federowicz reach the majors, the presence of Bard and Miller on his team would provide a “sense of comfort.” He said that although Bard and Miller controlled the games back at UNC, “I think we worked very well together, and I think they had a lot of success when I was back there.”

Added Federowicz, “I hope that it continues.”