The White Sox already traded their most valuable asset. By shipping Jose Quintana to the Cubs, Rick Hahn got the trade deadline moving. And you could safely assume that Hahn and the White Sox aren’t finished — David Robertson is likely to go somewhere soon. Ditto Todd Frazier. Ditto maybe a few other guys. The White Sox are selling, and this is what a sale looks like. There’s little sense in keeping present assets when the focus is squarely on the future.

It might feel like Quintana was the last major splash. Frazier won’t fetch very much, and Robertson comes with a pricey contract. I have a name for you, though, and it’s a name we’ve previously discussed. Now, around trade-deadline time, the prices for good relievers skyrocket. Every team in contention wants a better bullpen, and good relievers can be leaned on more heavily in the playoffs. It makes a certain amount of sense, and earlier, Dave submitted one reliever name who’s mostly off the radar. Me, I want to revisit Tommy Kahnle. Kahnle’s going to be a tricky one, because on the one hand, he’s just Tommy Kahnle, but on the other hand, holy crap. Maybe you haven’t seen what’s been happening.

I wrote about Kahnle’s hot start in April. Travis followed up in June. You can’t post awesome numbers without getting noticed, and we noticed what Kahnle was up to. All along, it’s been a question of: can this sustain? Is it a blip, or is it a breakout? Because the numbers have looked like breakout numbers. But relievers are, you know, relievers.

Kahnle has now worked in 37 games. He’s thrown 36 innings. You could call it a little more than half a season, or you could call it the equivalent of five or six starts. The point is just that the sample keeps getting bigger. And I’d like to share some information with you. Why don’t we start with Kahnle’s fastball velocities?

Kahnle can use his fastball to brush triple digits. It’s a hot one, and it’s hotter than ever. That’s one encouraging step. Why not also look at how Kahnle has done in terms of generating chases, out of the zone?

Again, looks like a new level. So let’s just get to the walks and the strikeouts. No more beating around the bush.

One season ago, with the White Sox, Kahnle looked mostly like himself, but he had 20 walks and 25 strikeouts. This season, as a guy about to turn 28 years old, he has seven walks and 60 strikeouts. His strikeout rate has doubled, in other words. And he’s trimmed more than two-thirds off his rate of free passes.

Kahnle still has a journeyman’s background. It can take a while for people to come around, and that’s sensible, because relievers are famously volatile. For example, consider, oh, I don’t know, 2017 Tommy Kahnle. But this version of this pitcher is something sensational, something outstanding, and in case you don’t believe me, you should consult the following table.

A Reliever Comparison Stat Andrew Miller Tommy Kahnle PA 171 141 Strike% 70% 69% 1st-Strike% 65% 64% GB% 40% 41% SwS% 16% 17% K% 40% 43% BB% 6% 5% K-BB% 33% 38% O-Swing% 42% 40% ERA- 36 57 FIP- 37 32 xFIP- 54 37 xwOBA 0.224 0.235

Has there been a bigger recent trade-deadline success story than Andrew Miller? Kahnle and Miller are different pitchers, with different styles, and Miller tends to work more often. Of course, you should consider Miller the more reliable of the two pitchers, today. But there’s no denying the statistical similarities. Take it for whatever it’s worth. Baseball is a game that comes down to its results, and, by the results, this year Kahnle and Miller have been on the same level. And Miller himself was a sudden pop-up at one point; he didn’t get good until 2012. He didn’t get great until 2014. Miller made adjustments, and hasn’t looked back. Kahnle has made adjustments. For the first time in his life, he’s found the strike zone. I don’t know if he’s going to look back, but this could be the start of something amazing.

Here’s a Kahnle fastball from a recent outing:

Here’s a different Kahnle fastball from the same outing:

He can be overpowering. He’s been overpowering. I know it’s not necessarily much to strike out Mike Zunino, and no one’s impressed if you blow away Jarrod Dyson, but videos are anecdotes. You’ve already seen the more meaningful data.

Among righty relievers, against righty hitters, Kahnle ranks fourth in baseball in K-BB%. That’s very good. Among righty relievers, against lefty hitters, Kahnle ranks eighth in baseball in K-BB%. That’s also very good. Kahnle isn’t so exploitable; he’s not a typical righty reliever, with a big giant platoon split. Everyone has had trouble catching up. Strikes and velocity are a hell of a combination.

Kahnle is nearly 28. He’s also in his final pre-arb year, which means he’s eligible for arbitration in 2018, 2019, and 2020. What that means is that he’s under about three and a half years of team control, so you might wonder why the White Sox would want to trade him in the first place. Technically, he could be seen as a longer-term asset. And that’s true, but to go back to something from the other day, rebuilding teams should subscribe to the idea of ABTR: Always Be Trading Relievers. They are volatile, and the known value is in the shorter-term. Kahnle would mean more to somebody else. Somebody with a shot. Somebody with a need.

What’s surprising to me is that the most recent time Tommy Kahnle has been tagged on MLB Trade Rumors is May of 2016. I haven’t really seen his name around, and I don’t get it. But teams out there are smart, and they surely know what Kahnle has been up to, even if rumors of interest haven’t flown around in public. Kahnle isn’t Miller, or Aroldis Chapman — he isn’t so much of a known entity. You don’t trade for Tommy Kahnle and instantly know you just made your October bullpen better. The mystery, the skepticism — they’re going to mitigate how much Kahnle could get. And yet, there will be intrigue, and there will be plenty of teams on the other end of the line. In getting Tommy Kahnle, some club in contention could land a possible bullpen-ace breakout. That would be more good news for a rapidly-improving White Sox farm system.