SEATTLE — From a plain-eyed perspective, it is almost impossible to notice any difference with the way Zach Eflin has thrown pitches since returning from the injured list.

It’s so minute that it takes advanced analytics to really tell, and even then, when watching slow-motion video or analyzing the graph that shows Eflin’s release point is, on average, two degrees lower than it was before his injury, it’s hard to believe that could be enough to impact him in any way.

“It’s enough,” Eflin assured.

Like anything, this isn’t as easy as X equaling Y. The two poor starts from Eflin last month, when he allowed a combined 12 earned runs, weren’t entirely a byproduct of an arm angle being slightly lower than it usually is. But the arm slot, as baseball folk call it, can factor into how pitches play, and the lower angle from which Eflin has thrown since returning from a lat strain impacted all of his pitches.

As pitching coach Drew French explained it, each pitch is like a signature. No two are exactly alike — the E in Eflin signed on one baseball card might look somewhat different than the next. It’s the same way in delivery, from minor fidgets in a pitcher’s windup to the exact location the ball leaves his outstretched fingers.

To expect identical form is to expect a robot.

Still, in baseball, pitchers hope to find a repeatable, efficient delivery for many reasons. One, it can help with durability. But it can also maximize movement, velocity and deception. If a pitcher threw a curveball from an over-top angle yet threw sidearm sliders, that would be an easy tell for hitters to know what to expect.

Now, back to Eflin. At the beginning of this season, the average arm slot for all of his pitches was 26 degrees. Since returning from injury, his average arm slot has hovered around 24.

It has been a more noticeable difference for his breaking balls, which had an average arm slot of 28.4 degrees on opening day. His most recent outing ahead of Thursday’s series finale against the Seattle Mariners saw his breaking ball arm slot drop to 23.8 degrees.

That is hardly noticeable. It also matters.

“I expect pitches to do certain things, and when I’m two degrees lower than what I normally am, they aren’t doing the same things,” Eflin said. “I’m getting more lateral movement on my curveball, as opposed to the depth I’m accustomed to. My splitter is doing different things. My sinker is going to run as opposed to going down. So, yeah, I think that’s a big thing I was running into the last couple outings. The shapes weren’t where I wanted them to be. I felt great. I felt healthy. Knowing it now, I was a little lower slot.”

As Eflin has matured, so has his form. When he pitched for the Philadelphia Phillies early in his career, his average arm slot was 31 degrees — closer to his ear. That has dropped naturally over the years, and it fits now with what French sees from the rest of Eflin’s body. After all, the arm doesn’t act independently while pitching. The legs, from his stride foot to his landing, play as large a part in the delivery as anything else.

In that sense, French categorized Eflin’s arm slot as less than an issue and more of an interesting byproduct of a pitcher adapting with his body.

“Our North Stars are obviously producing movement, velo, command and durability,” French said. “And so, kind of the diligent way that we track things and looking at the efficiency of the delivery, we do notice it’s different. But we also notice, based on, if you go back to, like, 2020 to present day, the way he loads his lower half and his drive leg is much different than what it was in Philly versus Tampa versus now.”

When Eflin considers it, he figures that his three weeks on the injured list may have led to the slightly dropped arm slot. He pitched in one rehab outing for High-A Aberdeen before returning to Baltimore and, as he built back up, French and Eflin noticed the lower slot on film.

It helps explain why Eflin’s command was less predictable than usual, particularly for his cutters. “By raising my arm slot, I’m able to get on top of it and get more lateral movement on it,” he said.

But he’s not actively thinking about the angle at which the ball leaves his hand when he’s on the mound. There’s too much else going through his mind when he’s in the middle of an inning — recording outs any way necessary, for instance.

Between innings, French said, he and Eflin will consult the iPad available in the dugout. On the tablet, they’ll watch replays and see instant pitch feedback, and Eflin can make immediate adjustments as needed.

“You can tell him, ‘Hey, it’s pretty low and it’s pretty early,’” French said of Eflin’s release point. The uncharacteristic arm-side misses seen in recent outings are a telltale sign when Eflin needs to tighten those mechanics.

“I pretty much know where the ball’s going at all times,” Eflin said. “I’ll have some slipups and stuff. But, when I’m consistently missing off the plate or I’m consistently, my curveball is not depth-y like it normally is, then I know something’s kind of up.

“Sometimes you try to remind yourself out there but you’re also trying to get a guy out, and sometimes there are guys on and a lot of stuff is going through your head,” he continued. “I’d say more so between innings is where we have conversations of, ‘Hey, your slot’s dropping,’ because they have mid-inning reports on what our stuff’s doing, looking at video on the iPads and stuff to see what our stuff’s doing. So it’s just one of those things where, the sooner you can correct it, the better it’s going to be.”

Still, when taken in the context of how Eflin’s whole body is moving, French isn’t overly concerned by the lower arm angle. If Eflin can record outs and stay healthy, that supersedes anything else.

But, when Eflin thinks of his inconsistent return from injury, he is reminding himself to get his arm just a tad closer to his ear. In a game of inches, this is an instance of degrees — and even a slight difference can trip up an experienced pitcher.