James Paxton, the New King from the North

Yesterday, the Mariners were completely and thoroughly shut down by Chris Sale. This isn’t unusual, as the funky lefty has been absolutely dominant this season. He’s struck out 211 batters in just 148.1 innings, and it’s no surprise that his FIP is correspondingly low: 1.92, best in all of MLB among pitchers with at least 100 innings pitched.

The name in that list’s runner-up position, however, might surprise you. No, it’s not all-world Clayton Kershaw, nor is it Max Scherzer or Corey Kluber.

Instead...

Joe Camporeale-USA TODAY Sports

Yep, you interpreted that correctly. It’s James Paxton slotting in at #2 in all of MLB in FIP.

Everyone who follows the Mariners knows that Paxton has been a completely different pitcher since visiting AAA last year and working with Tacoma pitching coach Lance Painter. To wit:

Side-note: Every single one of his top 20 single-game average fastball velocities are from either 2016 or 2017. Talk about lighting up the radar gun!

It’s one thing to improve, however, and another to be, arguably, one of the top five pitchers in all of baseball. In July, Paxton has a sparkling 1.49 FIP, with 38 strikeouts and only six walks in 33.1 innings pitched. Anybody who watched him on Monday saw the dominance evident in basically every pitch he threw.

Again, though, none of this is really new. Pax overhauled his motion last year (as detailed in this piece by Eno Sarris), not this year. Sure, The Maple Grove has been a breath of fresh air, but even its Eh-plus powers wouldn’t actually affect Big Maple on the mound. So what’s been the biggest difference?

In a word: luck. Or his contact profile, more specifically. You see, last year, hitters posted a .347 batting average on balls in play against Paxton, second-worst among all pitchers with at least 100 IP. (Incidentally, the one hurler with a worse BABIP is Robbie Ray, whose ERA has dropped from 4.90 to 3.15 this season while his FIP- has remained the exact same. Regression!) This year, that number is down to .297, or right around league average — and his ERA has followed, dropping from 3.79 to 2.84.

Of course, that’s not just because he was unlucky last year. His soft contact rate has jumped from 14.1% to 18.0%, with his hard contact rate falling from 33.1% to 29.5%. He’s generating more fly balls, and specifically more infield fly balls, which have an incredibly low BABIP. In essence, he’s probably less unlucky, but he’s also helping his defense out by giving them easier balls to field.

Paxton has also induced opposite-field contact at a career-best rate — in fact, his 33.7% oppo rate is best among all MLB pitchers with at least 100 innings this year, and just 1/10 of a percentage point behind the best season rate for any MLB starter in the past five years. It follows: if you hit the ball in the air, and to your opposite side, you probably won’t hit it very hard or very well.

Jose Rivera

The other big thing that Paxton has found is consistency. If you overhaul the mechanics you’ve been using your entire career, it’ll probably take some time to be able to repeat the motion every single time. Here’s a graph of Paxton’s horizontal release point over his career; check out how much more consistent he is in 2017 than he was in 2016!

And, for the sake of thoroughness, here’s his vertical release point:

The advanced stats do indicate a flaw or two, however. His HR/FB rate is second-lowest of the 74 pitchers with at least 100 IP this year, which tells me some of his noisy fly ball outs will soon turn into noisy fly ball home runs. Paxton’s xFIP is 3.28, a very good figure but not quite otherworldly.

But that’s a problem for Future Readers. Present-Day Readers shouldn’t worry about such troubles. James Paxton has figured something out, and he’s a bona fide ace. Let’s enjoy watching him once every five days, and let’s turn The Maple Grove into the new place to be at Safeco. James Paxton is ours, and you can’t have him.