What makes Andrew Miller so good? There’s a variety of contributing reasons — there’s the velocity, the fastball, the slider, the delivery, the body, the mentality, and so on and so on. Every part of Miller comes together to make him nearly perfect. But, what’s the mechanism? What’s the statistical explanation for Miller’s dominance? In essence, he warps the hitter’s idea of the strike zone. Hitters don’t swing at many strikes, and they swing at too many balls. They have the statistical discipline of bad-hitting pitchers.

So far this season, Miller has gotten opponents to swing at pitches out of the zone 43% of the time. Once again, that’s super high — by O-Swing%, Miller ranks second in baseball. There’s one guy in front of him. That one guy is Anthony Swarzak?

Sure, why not. It’s 31-year-old journeyman and minor-league-contract acquisition Anthony Swarzak, pitching out of the White Sox bullpen. I’ve already written about how Tommy Kahnle is overachieving. Now here’s Swarzak, too, basically out of nowhere. I’ve got a plot for you.

That’s Swarzak in red. Compared to last year, his O-Swing% against has improved by 14 percentage points, and his Contact% against has improved by 15 percentage points. So Swarzak is way, way out there, having now adjusted well to full-time relief. Let me take that back; Swarzak has mostly relieved for a while. First he was a starter. Then he was a swingman. Last year, with the Yankees, Swarzak for the first time dramatically increased his slider rate, overtaking his number of fastballs. Swarzak has kept that up in 2017. The difference this time around is in location. The Yankees got Swarzak to change his pitch mix rather aggressively. The White Sox have gotten Swarzak to focus on one specific area around the plate.

From Baseball Savant:

Last season, Swarzak threw 63% of his pitches to the glove-side half, which was one of the higher rates around. This season, Swarzak has thrown 85% of his pitches to the glove-side half, which ties him for the highest rate in the league. The next-closest pitcher trails by more than 10 percentage points. Swarzak works righties away, all the time. He works lefties inside, all the time. He throws his fastball to the glove-side, and he throws his slider to the glove-side. His locations have gotten precise, and consistent, and hitters haven’t really known what to do.

In January, Anthony Swarzak was basically nothing. I’m going to guess he signed with the White Sox because he figured there he stood a better chance of getting a big-league opportunity. He was right! And for a month and a half he’s been one of baseball’s more effective relievers. I don’t know what to tell you. This is our shared reality. How about Anthony Swarzak?