Brewers Farm Update

Nathan For You

His BP profile page might not reflect it yet, as it still sits vacant dating back to 2015, but one of the Brewers’ most intriguing mothballed minor-leaguers is finally getting his professional career off the ground.

Nathan Kirby was drafted in the supplemental first round of the 2015 amateur draft, 40th overall, by the Brewers out of the University of Virginia. At the time, it was considered a great value pick by the Brewers. Kirby had been a candidate to go in the top 10, or even the top 5, just months before the June draft. But inconsistent stuff and command, plus a strained lat that sidelined him for a time, plagued his senior year and he slipped to the supplemental round.

Just five appearances into his professional career, the Brewers shut Kirby down for Tommy John surgery, which is a fate that surprised few, given how he had regressed as a pitcher in 2015. Kirby missed all of 2016 rehabbing from the surgery, and this spring the team elected to keep him at extended spring training when the season started. But something still felt wrong.

Thanks to this latest setback, Kirby is just now getting to a mound again in late September, and has lost two full years of development since getting drafted. Going forward, it’s impossible to say what to expect from the once-promising lefthander.


In 2013, Kirby’s freshman year, he pitched primarily out of the bullpen for Virginia, making 22 relief appearances and 2 starts. His strikeout ratio aside, he didn’t really look the part of a future star that year, and three other freshman pitchers–Brandon Waddell, Josh Sborz, and Trey Oest–all saw more innings than Kirby. But that summer he pitched for the Keene Swamp Bats of the New England Collegiate League, won a spot in the Swamp Bats’ starting rotation, and went 3-0 with a 1.67 ERA in seven starts and a relief appearance. Kirby’s 12.56 strikeouts per nine innings were enough to turn some heads, too, and the sophomore was able to ride the momentum into Virginia’s 2014 starting rotation.

That year, Kirby made his case for a future career in the Major Leagues. He struck out 112 batters in 113.1 innings, posted a sterling 2.07 ERA, and issued just 2.63 walks per nine innings. And in those 113-plus innings, he surrendered just one home run. On April 4, 2015, he recorded probably the best pitching performance of the 2015 season by a collegiate hurler: an 18-strikeout no-hitter against the Pitt Panthers.

But just as quickly as Kirby had emerged, the hype was extinguished. Kirby’s walk rate spiked in 2015, from 2.62 to 4.5 BB/9, and he missed significant time with what was called a strained lat. Despite Virginia’s triumph at the College World Series, despite his polished surface stats, Kirby’s draft stock tumbled. When the Brewers found him available at 40 overall, it was too tantalizing to pass up.


Looking back, it’s not hard to isolate the significant factors which led to Kirby’s arm problems. As a 19-year-old college freshman in 2013, he pitched just north of 75 innings combined between spring and summer. He pitched out of the bullpen for the Cavaliers in the spring, and averaged fewer than seven innings per start for the Swamp Bats in the summer. One year later, in the above docu-short about Kirby’s historic no-hitter, his coach looked at the camera straight-faced as can be and said “It’s just amazing that you throw a no-hitter, and you have 18 strikeouts, and only throw 120-some pitches.”

(I added the boldface myself to highlight one of the most irresponsible butcherings of the English language I have ever heard come from the mouth of an adult human. “Only” 120-some pitches. He actually effing said that. That’s like going in to the doctor for your physical, and he wants to test you for STDs, and you tell him that you don’t need to bother because you’ve “only” had 50 new sexual partners in the year since your last physical. These are not contexts in which use of the word “only” is correct. But I digress…)

In addition to this sudden and violent acceleration of workload, Kirby the college pitcher had the type of mechanics that are all but guaranteed to result in serious injury.

That “Terrible T” that Chris O’Leary refers to in the tweet and the blog post it links to also appears in Tucker Blair’s BP Eyewitness Report on Kirby, which was written on the one-year anniversary of his 18-strikeout no-hitter that “only” took 120-some pitches. Blair calls it an “exaggerated stab,” not a “terrible T,” but the straight-arm pause pictured above is what both writers are communicating through very different phrasing. As O’Leary, a former collegiate hitting instructor who counts several current and former professional players among his clients, concedes in his blog post, this technique is effective in creating rapid, short-term velocity gains for young pitchers, “but those velocity gains are achieved by overloading the arm. It’s like running a car engine past the redline. It works. For a while.”

By the time Blair was scouting Kirby, his arm was already the equivalent of a dying engine that idles loudly and struggles to generate the power it’s capable of. Blair harshly graded his command as “fringe” to “fringe-average” across all three of his pitches, and repeatedly hammered his mechanics throughout the report, even suggesting bluntly that they “are in much need of work.” But don’t take his word for it. You can see the problem yourself in this video shared by FanGraphs in the leadup to the ’15 draft:

If you’re wondering why I cued the video in at the six second mark, well, it’s because that point marks the first of eight consecutive pitches in 40 seconds from the exact same camera angle; perfect for watching a pitcher’s mechanics over and over. And wouldn’t you know it, on each and every pitch thrown by Kirby his pitching arm comes to a complete stop in that exaggerated, straightened position before whipping forward wildly. Rather than his throwing arm working in sync with his lower body, that exaggerated stretch back and extended pause cause his lower body to come out of the stretch ahead, and his arm has to work overtime to catch up. This is exactly what O’Leary calls “running the engine past the redline,” how a pitcher can overstrain his elbow and shoulder to bleed extra velocity out of his arm. It’s simply not sustainable long-term.


That the Brewers are taking their time with Kirby, by keeping him in extended Spring Training early on this year, and now working him out patiently in the instructional league, is a good sign for the team, and its fans. He can still be a successful Major League pitcher. Fans would be foolish to expect that he will be a successful Major League pitcher, but he’s still just 23 and has proven himself capable of pitching at a high level. His fastball, slider, and curveball have all flashed plus at various points throughout his young career, and his changeup is capable of generating a lot of ugly, swinging strikes off of said fastball. Two years ago, before noting that his mechanics need refinement, Tucker Blair assessed in his conclusion that “there is a feel for pitching” in Kirby, and while you can teach proper mechanics, you can’t teach that. Put that whole package together and you’ve got a pitcher who could potentially help a Major League rotation someday. But it will be a far longer, and far less certain, journey to that destination than anyone foresaw in June of 2015.

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