The Yankees added a violent weapon to their arsenal in the summer of 2017 when they acquired right-hander Tommy Kahnle from the White Sox in a package deal that netted them veterans David Robertson and Todd Frazier. In his first season of donning the pinstripes in the Bronx, Kahnle posted a 2.70 ERA, 2.30 FIP, and a 12.15 K/9 in 26.2 innings pitched.

He pitched very meaningful innings that postseason, coming out of the pen in huge spots in the AL Wild Card game (2.1 innings), ALDS, and the ALCS. During that postseason, Kahnle compiled a 2.38 ERA in 11.1 innings pitched over seven appearances.

The New York Yankees had high hopes when it came to Tommy Kahnle going into the 2018 campaign. However, the right-hander only logged 23.1 innings with the major-league club in 2018 as he allowed 17 earned runs (6.56 ERA, 4.19 FIP).

Even though opposing hitters’ exit velocity was down from 2017 (87.5 mph in 2018, compared to 88.3 mph in 2017), more batters were barreling balls up. He allowed just five barrels across 1017 pitches thrown in 2017 (3.5% barrel rate), but he allowed seven barrels across 485 pitches in the majors in 2018 (11.3% barrel rate).

Kahnle’s control problems that had plagued him in the past (18.1% walk rate in 2015, 16.8% walk rate in ’16) has returned in 2018, as he walked 14% of batters. When he was at his best in 2017, he was only walking 6.6% of batters.

However, Kahnle has completely re-found himself again in 2019 with the Yankees. In 16.2 innings pitched out of the pen this season, he’s posted a 1.08 ERA, 2.20 FIP, and a 12.42 K/9.

Batters are only hitting .119 against him. He’s striking out batters at a 33.3% rate and only walking 9.5% of batters.

Kahnle’s .145 XBA (expected batting average against), .206 XSLG (expected slugging percentage against), and .232 XWOBACON (expected weighted on-base percentage on contact against) sit in the top-1% in all of baseball, according to Statcast. All of these numbers support why Kahnle has been so dominant so far in 2019.

These numbers also pretty much say that what he’s doing right now isn’t a fluke, by any means.

Kahnle had lost his fastball velocity in 2018, averaging out at 95.1 mph after his fastball averaged at 97.8 mph in 2017. Hitters were hitting .383 against it in 2018 with a XSLG of .605 and a 91.2 mph average exit velocity, after hitting .225 with a 89.4 mph average exit velocity the year prior.

With him losing his fastball velocity and getting shelled when throwing it, Kahnle started throwing his fastball less than usual. He had thrown it at a 63.4% rate in 2017 and 61.5% rate in 2016, but he threw it just 54.4% of the time in 2018.

Kahnle can’t throw his wipeout changeup and be dominant with it if he’s not successfully throwing his fastball.

His fastball velocity is back in 2019, as it’s averaging 96.2 mph and hitters are only posting a .185 batting average against the pitch, along with a XSLG of .203 and an average exit velocity of 88.8 mph. With the velocity back, he’s throwing it close to as often as he did in 2016-17, throwing it 58.2% of the time this season.

Going back to Kahnle’s wipeout changeup, batters haven’t been able to touch it this season, posting a batting average of .042 against it, along with a XBA of .099, .181 xSLG, 82.7 mph average exit velocity, and a 46.2% whiff rate.

In 2017, Kahnle threw 21.8% changeups and 11.6% sliders. This season, he’s using his changeup on 35.5% of pitches and his slider on only 6.2%.

Because of that, opposing hitters aren’t able to lift the ball into the air. The average launch angle against Kahnle is 4.0 degrees, compared to 4.2 degrees in 2018 and 14.9 degrees in 2017. Over the first five seasons of his career, he had never had a roundball rate better than 54.8%. This season, it’s 63.9%.

Kahnle’s slider is pretty much non-existent at this point—and that’s helped him early on in 2019 in keeping the ball on the ground and out of the air.

Kahnle has had one bad outing all year, which was when he allowed two earned runs on four hits (one home run) in two-thirds of an inning in Houston on April 9. Outside of that outing, he hasn’t allowed an earned run and has only allowed three hits (all on May 7 against the Mariners) in 16 innings.

The man has been sensational in 2019, and that’s helped the Yankees in a huge way in the absence of Dellin Betances. In a bullpen that has the likes of Aroldis Chapman, Adam Ottavino, and Zack Britton—all of whom have had solid starts to 2019—Kahnle has been the team’s greatest and deadliest weapon out of the bullpen.