It was an inauspicious start to the season for Michael Feliz. It’s been an inauspicious start to the season for the entire Houston Astros ballclub. One of them’s turned it around, providing hope to the other.

Feliz’s numbers, on the whole, are impressive, and even they come with something of an asterisk. In 20 innings of relief work, the 22-year-old right-handed rookie has struck out 33 batters and walked four — only two pitchers in baseball currently have a better K-BB%, and they both wear pinstripes. You’ve probably heard of them. The asterisk is that Feliz has walked just four batters all year, and they all came in his season debut, a 107-pitch relief outing back on April 6 after starter Collin McHugh recorded just one out. Feliz was thrust into action in the first, asked to eat innings, faltered, and was promptly sent to the minors for a fresh arm. He was recalled a couple weeks later, and since then, he’s been completely unhittable.

Dating back to that April 26 recall, Feliz has struck out half of the batters he’s faced, and he’s walked none of them. He’s getting ground balls, and he’s working multiple innings. Before the year, you might’ve only known Feliz’s name by being an Astros fan or a prospect hound — while he fell just outside of preseason top-100 prospect lists, most evaluators viewed him as a top-10 piece in a deep Astros’ system. Now, he’s turning heads, with the kind of numbers that practically demand attention.

The fastball sits 94 and touches 98, and while it’s always the heater that makes itself most visible, it’s Feliz’s slider that’s really stuck out. He says he’s been focused on working on the pitch, pitching coach Brent Strom says the shape and power of the offering make it a completely different pitch than the one he first saw in 2013, and manager A.J. Hinch agrees that it’s a “full grade better” than it was last year. The numbers can’t speak to what it was before, but they can paint a pretty good picture of what it is now.

Take every pitcher with at least 100 sliders thrown this year, and sort them by swing-and-miss rate. Feliz shows up fourth, right behind Andrew Miller and right ahead of Corey Kluber. Feliz has thrown 102 sliders, gotten 40 swings, and on more than half of those swings, the hitter’s come up empty. Nobody’s gotten a hit off it in more than a month. It’s worth pointing out, too, that on that same slider whiff rate leaderboard where Feliz is fourth, Feliz’s teammates, Luke Gregerson and Ken Giles, are one and two. As far as the slider goes, Feliz shows up to work surrounded by good company.

So, that improvement to which Strom and Hinch both referred? It comes in the form of velocity, where Feliz has picked up a tick since last year, and it comes in the form of movement, but more than anything else, it might come in the form of consistency. The concern among scouts with Feliz, beyond the development of a third pitch, which we’ll get to momentarily, was always the command of the secondary offerings. From Baseball America’s offseason scouting report, Feliz “rips off a good slider roughly two out of every five times he throws it.”

What Feliz has shown this year is a slider that’s been consistently buried along the bottom edge of the zone, and rarely left out over the plate:

Let’s watch an at-bat. It always helps to watch an at-bat. I watched a handful, and one in particular against Manny Machado stuck out as something close to representative of the way Feliz works, and how it might inform his present and future standing. Let’s now observe.

Feliz starts Machado off with a slider that misses for ball one, but nearly generated the sort of swing Feliz wants. Despite falling behind in the count, this pitch is in a good spot, and in my book it counts for “ripping off a good slider.” We also take note of the fact that his over-the-top delivery gives this pitch more of a 12-6 plane, suggesting it might be more effective against opposite-handed hitters than the typical slider.

Now we get to see the heater. It comes in at an easy 96 and it gets another check swing, but another that’s held, and Feliz is down in the count 2-0 after two pretty good pitches.

Machado, ahead in the count, is almost certainly sitting fastball. He get sit, but Feliz hits the glove on the outer-half of the plate, and Machado can only foul it off.

There’s one of those bad sliders, the type scouts saw too many of in the minors, the type Feliz has been attempting to (and mostly succeeding to) eliminate. But they still exist from time to time, and one rears its ugly head here, putting Feliz on the brink of his first walk in a month.

Back with another good fastball, thrown when Machado would be expecting one, but spotted well enough to prevent any damage. Count full.

That swing Feliz didn’t get on the first pitch, he gets here. The 3-2 slider suggests great confidence in a secondary offering largely viewed as inconsistent, and the result rewards the battery’s confidence. It’s spotted perfectly, it’s 14 miles per hour slower than the previous pitch, and it makes one of baseball’s best hitters look silly.

It’s the kind of at-bat that makes you want to see more, and evidently, seeing more of Feliz is a discussion the Astros are having, with Hinch saying that Feliz could have the stuff to be a starter with improvement of the changeup. The fastball has improved, the slider has improved, but we didn’t see a changeup in that Machado at-bat because Feliz hasn’t thrown a changeup to a righty all year. Righty-on-righty changeups aren’t particularly common, though they’re becoming more so, and it could just be that Feliz hasn’t needed one. But it also hints at a lack of confidence in the pitch, which can only be reinforced by this:

That’s every Feliz changeup this season, and that’s not a particularly inspiring image. He’s thrown them exclusively to lefties, perhaps because if he were to throw one to a righty, he might end up with a hit batsmen.

The fastball’s seemingly improved, the slider’s seemingly improved, and with 29 strikeouts and zero walks over his last 59 batters, it sure looks like the Astros have themselves a new weapon out of the bullpen. The lack of a consistent third pitch may keep him there for now, but the improvement of two other pitches leaves hope yet. And a bullpen weapon is better than no weapon.