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BRADENTON, Fla. -- There is a good amount of uncertainty in the Pirates’ projected Opening Day rotation. Mitch Keller is an All-Star and a fine head of the group, but after him are a pair of veteran lefties looking to have bounceback seasons (Marco Gonzales and Martín Pérez) and two spots up for competition. There’s potential, but also question marks with the starting five.

The bullpen, on the other hand, is shaping up to be one of their best units in years. Aroldis Chapman was the team’s most lucrative free agent pickup this winter, and he should join Colin Holderman and Carmen Mlodzinski as the team’s primary leverage relievers. Dauri Moreta, Ryan Borucki and Jose Hernandez all emerged as specialists last season, and two-time All-Star David Bednar is waiting in the ninth.

There may be some questions about the first half of the game pitching-wise, but the Pirates are banking on the back half being solid.

“It's a group I was really excited for going into this year,” Bednar said. “Then you add a guy like Chapman, it takes it to a whole ‘nother level. It's a really good group.”

It wasn’t too long ago that the Pirates’ bullpen was a landing spot for pitchers who had struggled in the Majors or were trying to find a new home. The team did strike some gold in those areas, especially guys such as Borucki and Moreta, who leaned into more breaking balls to find a personal identity. Now, they can reap some rewards.

“Understanding their identity, who they are as a player and what their strengths are, we can work off of that,” catcher Yasmani Grandal said. “At the end of the day, we’re going to pitch to our strengths.”

That group identity isn’t limited to the pitchers' stuff, either. One of this bullpen’s greatest strengths may be the uniqueness of how this group throws the ball.

“We have a lot of power, but a good mixture of power and finesse,” Borucki said. “The best bullpens I’ve ever been a part of is everyone’s a different look. The successful bullpens I’ve been in, no one’s the same. I think that’s what makes some teams really special.”

There are two main ways to describe those different looks. The first is pitch mix. Moreta is a slider specialist, throwing it 64.8% of the time last season. Holderman’s arsenal could grow to as many as five pitches this year, depending on how much he wants to implement his four-seamer and changeup. Both could be used in leverage or mid-inning fireman roles at points this season. Manager Derek Shelton has more flexibility to pick based on matchups.

On the lefty side, Borucki can offer four different pitches, and Hernandez threw his slider 55.9% of the time in 2023. If both are in the bullpen, the skipper has the same freedom to choose.

The second way is perhaps the most intriguing: the different arm angles of each pitcher. Below is a look at four main pitchers from last year’s bullpen in a game on Sept. 22. Here is where Bednar, Borucki, Hernandez and Mlodzinski released the ball that game:

It was four pitchers offering four very different looks. There is a bit more overlap now, as Chapman and Hernandez throw from a similar arm slot, but Hernandez leaned on his slider more last year. Chapman is going to pump triple-digit heat from that same arm angle. That’s still challenging for a hitter.

“You never want to be throwing out the same type of guy two or three times in a game,” Borucki said. “By the third guy, it’s the same mix. I think that’s the key to this bullpen. Everyone’s a different look.”

The Pirates need this bullpen to be successful. They have some talented arms in the mix, and not all of them are going to make the Opening Day roster. This team has more optionable reliever depth than it had had in the past, and those relievers can play into this many-different-looks bullpen.

“It’s definitely a weapon,” Shelton said. “I think we’ve seen teams that have built really effective bullpens with guys who can do different things with different repertoires from different arm angles. So, it’s something that we’ve been very aware of, in terms of how we’re going to build our bullpen. And it’s not just the eight guys who are going to be in it but the guys that go to [Triple-A Indianapolis], too, and the weapons they have to come up and facilitate.”