One of the classic criticisms of the front-page entries on FanGraphs is that it can sometimes look like writers are just scanning different leaderboards until they find a subject. Now, there’s nothing actually wrong with that, I don’t think. That’s why the leaderboards exist — so we can all learn from what they say. It’s not like we can easily and automatically keep track of everything by ourselves. Still, I understand where the criticism comes from. And so I’d like to be up front here: This post is about something I didn’t expect to see on a leaderboard. There’s no deeper inspiration. But when I saw a player’s line, I knew I couldn’t not write about it.

In the early going this season, the White Sox have been a pleasant surprise! They’re hanging tight with the Indians, and they’re well ahead of, say, the Royals. One element that’s driven the White Sox has been the pitching staff, and, specifically, the bullpen. Even coming into the year, the team had Nate Jones and David Robertson, so the bullpen wasn’t likely to be terrible. To this point, it’s second out of all big-league bullpens in ERA-. It’s first in K-BB%. That…isn’t what anyone expected. And now, a plot.

This is a simple plot of strikeout rate and walk rate. It includes every single pitcher who’s faced at least 25 opponents. That’s a small minimum, I know, but what do you want? It’s April 28. Everyone who isn’t on the White Sox is in transparent gray. Everyone who is on the White Sox is in black.

There are four White Sox pitchers toward the upper left. That area includes Zach Putnam. It includes Robertson. Somewhat surprisingly, it includes Anthony Swarzak, which, okay. Maybe Swarzak deserves a post of his own. But there’s one guy really up there. One guy with an FIP of -0.88, and an xFIP to match. The pitcher in question has faced 27 batters, and he’s struck out 15 of them. He’s issued one single walk. Don’t tell me about sample size. I know about sample size. It doesn’t make this performance any less impressive. Would you believe me if I said the pitcher up there is Tommy Kahnle?

Don’t feel bad if you aren’t familiar with Tommy Kahnle. To be completely honest, I only just learned the proper way to pronounce his last name. Kahnle joined the White Sox after being DFA’d by the Rockies. He joined the Rockies after being selected as a Rule 5 pick from the Yankees. Kahnle is 27 years old, and he’s not even a household name in Chicago. But this is one of those performances that you can’t pull off without having a certain bare minimum level of talent. To do what Kahnle has done is stunning, and his track record makes it all the more stunning still.

Don’t like comparing a fraction of one April against three other whole seasons? Very well.

Kahnle hasn’t pitched close to this level before. He didn’t tease with an amazing spring training. This was so unexpected Kahnle didn’t even break camp with the big-league club — he was optioned to Triple-A on March 22. He came back as an injury replacement two weeks later. Said Don Cooper:

“His arm doesn’t belong in the minor leagues,” Cooper said. “The only thing between him and staying here forever is just throwing his fastball, his breaking ball, his changeup over the plate.”

Right — control. Kahnle didn’t used to have control. I’d like to show you a selection of three of Kahnle’s most recent pitches. These pitches are pulled from a six-pitch strikeout of Salvador Perez on Wednesday. Two of these pitches were balls. None of the six pitches were horrible; I just didn’t want to include six clips when three will suffice.

First pitch: ball. No one wants to fall behind 1-and-0, but that’s a splendid first pitch. Just didn’t get the call. Oh, right, 99. Did I mention that Tommy Kahnle throws 99 miles per hour?

The count advanced to 1-and-2. Here’s how Kahnle tried to put Perez away.

Perfect changeup. I don’t know how Perez managed to hold back. 93. Perfect changeup at 93 miles per hour.

Perez, ultimately, got blown away.

Triple digits, located right on the black. An arm like Kahnle’s means you’ll get chance after chance to figure it out. Many times, a big-armed pitcher never quite figures it out, and the career performance record is spotty. I’m not saying Kahnle has figured it out, but he has been completely unhittable, and I’m reminded of Matt Thornton. Thornton threw hard when he was younger, but he walked one of every six batters he faced. The White Sox picked him up and Cooper immediately shaved seven points off Thornton’s walk rate. He became one of the league’s more reliable lefty relievers, and all it took was a fairly simple mechanical correction. Cooper fixed Thornton in 2006. The Sox might’ve fixed Kahnle in 2017. Or perhaps Kahnle fixed himself.

Here’s a clip of Kahnle from last summer:

He looks like basically the same pitcher, but keep your eye on Kahnle’s front foot. Compare this clip to the earlier clips, from Wednesday. I can spot what seems like a fundamental adjustment. In the clip from last year, Kahnle lands almost on the ball of his foot, and his toes are turned toward the righty batter’s box. He closes himself off a little bit, and has to throw across his body. More recently, when Kahnle has pitched, he’s directed his toes just about right at the catcher, and he’s landed more naturally, heel first. Kahnle has himself more in alignment, and although this might just be a fleeting mechanical fix, it’s clearly made an enormous difference. And if Kahnle keeps this up, well, what’s stopping him from season-long dominance?

Kahnle already threw hard before, but his average fastball in 2017 is up nearly two miles per hour. According to Baseball Savant, Aroldis Chapman is the only pitcher with a higher perceived fastball velocity. Kahnle gets it up there at 98 – 100, and although his zone rate, specifically, hasn’t budged much, you might’ve noticed that Baseball Savant recently introduced new pitch-location buckets. I selected all the zones that are either strikes or near-strikes, and this year, Kahnle has one of the game’s very highest rates. He’s right there with pitchers like Jake McGee, Craig Kimbrel, and Sean Doolittle. Kahnle is more consistently around the zone, presumably thanks to his streamlined delivery, and batters so far have been helpless. They’ve swung at half of Kahnle’s would-be balls, and even in the zone, just 62% of swings have made contact.

I understand that I’ve just cleared a thousand words on a journeyman middle reliever on a rebuilding team. Kahnle’s been good for a few weeks, and now his career WAR is up to 0.4. For all I know, Kahnle’s about to lose the zone again, and that’ll be that. But, the stuff is clearly there. And for the first time ever, Kahnle is pitching like a pitcher in control. A subtle mechanical adjustment can sometimes yield impossible gains. Watch Tommy Kahnle, and don’t lose hope. Power-armed pitchers are always floating around, seldom scraping their ceilings. Sometimes, they can get to those ceilings. Kahnle’s gotten to his in April. We’ll see about May.