Zac Lowther has been deceptively good. In 20 starts this season between Low-A Delmarva and High-A Frederick, the 22-year-old southpaw boasts a 2.11 ERA and has punched out 134 while allowing just 76 hits in 106.2 innings. He came into the campaign No. 10 on our Orioles top-prospect list — no other publication had him ranked higher — and his propensity to miss barrels is due in large part to his delivery. Eric Longenhagen described the 6-foot-2, 235-pound hurler as “a low-slot lefty with vexing funk.”

Lowther has heard similar things from opposing hitters.

“I don’t have overwhelming velocity, but guys tell me the ball kind of jumps out of my hand,” related Lowther, whom the Orioles drafted 74th overall last summer out of Xavier University. They’ll say, ‘I don’t know what you do,’ and I’ll be like, ‘I just throw the ball as well as I can.’ It’s not something I actively think about. It’s more of them telling me I’m deceptive, as opposed to me figuring it out.”

Which doesn’t mean that he hasn’t figured out. Pitchers almost always understand what makes them effective, so Lowther knows as well as anyone why he induces a lot of uncomfortable swings.

“I’m very quick with my arm,” explained the lefty. “My angle is low three-quarters, and the way my arm comes through… it’s a whippy motion. There’s a lot of external torque going back, and then I also have good extension, a really long stride. My arm gets way out in front of my body, and I release it from there.”

Scouting footage of Lowther at Xavier.

He also has above-average spin, which helps his low-90s fastball play up even more. Lowther’s heaters are all four-seamers — a two-seamer is “something I’m looking into maybe adding” — and he throws a boatload of them. While that pitch will remain his bread and butter, he does see a need to “start working in more offspeed pitches, and sequencing better” as he moves up the ladder. He considers his changeup — “it’s a modified circle” — his second-bast pitch and his curveball the third-best one.

The erstwhile Musketeer augments his deception with strike-throwing ability. And while he considers himself “more of a location-and-command guy who prides himself in being able to work both sides of the plate and up and down,” he’s not a finesse-maven reliant on his defense. Lowther led the Cape Cod League in strikeouts in 2016, and last year he set Xavier’s single-season strikeout record before becoming the Big East school’s highest-ever draft pick. His K/9 in 160 professional innings is a crisp 11.7.

A lot of number-crunching was happening behind the scenes as Lowther headed into the 2017 draft. But while Xavier “had Rapsodo, and my coaches gave that data to some of the scouts,” most of his pre-draft conversations were more traditional in nature. Regardless of the subject matter, his hometown team wasn’t among those actively kicking the tires.

“I didn’t have many conversations with the Indians,” Lowther told me. “It would have been nice, with me being from Cleveland, but they didn’t show a lot of interest. The only team that really came out and said anything was the Padres. For the most part, it was pretty quiet until draft day.”

It would be an exaggeration to say that Lowther is creating a loud buzz in his first full season. By and large, he’s still under the radar in terms of national recognition. But as for the hitters who have stepped into the box against him this summer… let’s just say radar might come in handy. You can’t hit what you can’t see, and thanks to “vexing funk,” Lowther has been delivering plenty of invisiballs. He’s emerged as a must-watch prospect in the Orioles organization.