For years, the presence of Grayson Rodriguez and DL Hall atop the Orioles’ pitching prospect depth chart meant there was a huge gulf between them and the next level of players who eventually could help the major league team.

It didn’t help that, during that time, the Orioles acquired pitchers primarily in the back half of or after the draft, or in trades that subtracted from the major league team. Factor in a pandemic that kept many of these pitchers off a mound for a full season in their formative years, and it has taken time to sort out what the Orioles have in terms of pitchers on the farm.

Now that eyes are turning to the next wave of arms coming through the system, it’s time to figure out a way to present them to the world. Cade Povich has distinguished himself over the last year, but others are emerging as well. Throughout the season, this series — Arms on the Farm — I’ll use firsthand observation, data analysis and insights from the pitchers and their coaches, along with opinions from professional scouts who cover the Orioles, to provide as much information as possible about these prospects.

We’ll begin with Justin Armbruester, a breakout arm from 2022 who is off to one of the system’s best starts at Bowie in 2023.

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Where did he come from?

The Orioles’ emphasis on selecting pitchers on the third day of the draft has become apparent in recent years, and Armbruester, a 12th-round senior signee out of New Mexico in 2021, is one of the better examples of that paying off. He was conference pitcher of the year at NCAA Division III Pacific Lutheran in 2019 after leading the nation in strikeouts, then again at the Division I level after transferring to New Mexico.

What do the numbers say?

Armbruester has been developed as a starter for the entirety of his pro career, beginning last year at High-A Aberdeen. He made 12 starts with a 4.02 ERA, a 1.12 WHIP and a 4.53 fielding-independent pitching (FIP, which approximates ERA based on controllable factors for a pitcher such as strikeouts, walks and home runs), while striking out 10.57 batters per nine.

At Bowie last year, he made 14 appearances (10 starts) with a 3.69 ERA, a 1.03 WHIP, a 5.04 FIP and 8.95 strikeouts per nine in 63 1/3 innings. Through seven starts this year, he has a 1.58 ERA, a 1.10 WHIP and a 4.17 FIP, while striking out 29 in 40 innings.

Taken together, Armbruester has a 3.27 ERA, a 4.65 FIP and a 4.15 xFIP — which normalizes home run rate to the league average — over 157 innings between Aberdeen and Bowie. He has 8.89 strikeouts per nine and a 1.08 WHIP. Out of 504 pitchers with at least 100 minor league innings since the start of last season, his WHIP ranks 27th.

It seems his home run rate explains most of the relatively wide discrepancy between his expected and actual statistics, because Armbruester has yielded 1.43 home runs per nine since the start of 2022. He allowed 21 home runs in 2022 but just 11 doubles. That could come down to park effects and conditions, but he also might have been having his mistakes punished in the most drastic way possible. This year in Bowie, he’s controlling that better, having allowed four home runs in 40 innings (0.90 per nine). It could also have just been noise, but it is worth monitoring as the season progresses.

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What does he throw?

The Orioles have clearly targeted pitchers with specific traits, in the draft and in trades. Armbruester boasts those traits and is an example of some of the development paths that can grow off that.

He has a riding four-seam fastball with hop that sits in the 91-93 mph range and plays up because of a funky arm action. It has the ability to miss bats up in the zone and broadly stay off barrels. It’s an above-average pitch, although there’s plus potential in short spurts if he ever moves to the bullpen. The four-seam/sweeper combination that the Orioles seem to favor is a significant feature of his arsenal because he added sweep to his low-80s slider throughout 2022 and now features the pitch prominently to righties.

Around the midway point of 2022, shortly before he was promoted to Bowie, Armbruester started working on a cutter that sits in the 88-90 mph range and ended up generating the highest percentage of swinging strikes in his arsenal. Both play as average pitches with the potential for a tick better than that.

His cutter is seen as an effective pitch against lefties because it runs in on their hands, but Armbruester has been trying to add another pitch — be it a changeup or a curveball with more horizontal break than his sweeper. On May 16 in Bowie, he mixed in some curveballs in the high-70s as that weapon, although earlier in the season he was still using a changeup.

That he has improved the sweep on his slider, added a cutter and now brought along a curveball speaks well to Armbruester’s ability to spin the baseball. His aptitude at developing them means there’s hope he can continue to develop a changeup or, given the Orioles’ favorable view on the pitch, a splitter, to give him a way to attack lefties better.

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Outside of his raw stuff, Armbruester’s success is bolstered by his ability to fill up the strike zone and locate quality pitches. He had one of the top zone rates in minor league baseball last season, and he is continuing to throw strikes in 2023.

What does the future hold?

Armbruester’s pitch mix and talents make it easy to see why he’s had the success he’s had. They make a path to at least the major league bullpen realistic for him. Continued refinement of the pitcher he is now, with his current arsenal, would make Armbruester a relatively standard right-on-right reliever who could pitch multiple innings or maybe work in bulk on the right day.

It’s at once necessary and unfair to focus on what someone with that many pitches doesn’t have in his arsenal, but here’s where Armbruester’s effort to add a weapon to use against lefties comes in. Left-handed hitters fared far better than righties against Armbruester in 2022. Lefties had an .836 OPS and 12 home runs in 163 plate appearances against him, compared to a .564 OPS with nine home runs in 265 plate appearances for righties.

That has neutralized somewhat in 2023; he’s faced 80 lefties and 80 rights this year, with lefties producing a .679 OPS and righties a .583 OPS. There are plenty of right-handed major league starters who get by without a changeup, although they compensate with elite pitches elsewhere in their repertoire.

Armbruester has the benefit of development time before a determination on his future needs to be made. The Orioles are loath to move anyone to the bullpen before they have to, and even once he gets to the more crowded rotation in Norfolk he’ll likely pitch in bulk outings to continue his development in longer spurts. There’s no rush, because he’s not eligible for the Rule 5 draft until after next season. In the meantime, Armbruester can work off the widely held belief that he can at least come out of a big league bullpen while attempting to enhance his arsenal for a more significant role with the Orioles down the line.