James Paxton’s worst pitch became his best pitch

No matter how you spin it, 2016 was a successful year for James Paxton.

Did it start well? Not at all. A subpar spring left him as the odd man out in a competition for the fifth spot in the starting rotation, resulting in a two-month stay at Triple-A Tacoma to start the year. His performance with the Rainiers was okay, at best: 50.2 IP, 4.06 FIP, 3.53 K/BB, and an inability to consistently work deep into games. And it’s not as if the results started out poor and got better as the year went along; in two of his final three starts he surrendered a combined 11 earned runs on 13 hits in in 9.2 innings.

He was hardly in a place where a call-up was ideal, but we all know the story: Mariners starters were hurt and hurt often. Thirteen different pitchers started a game this season, including multiple relief pitchers and something named Joe Wieland. Whether they wanted to give James Paxton more time or not, there really wasn’t a choice. He was called up in June to start against the Padres and away he went, and boy did he go:

Wow, tenth in all of baseball isn’t bad, but wait! A lot of those guys ahead of him have pretty tiny sample sizes. Got something a little more substantial for us, Jon?

That’s better.

So, what in the hell happened between 2015 and 2016 that turned Paxton into a juggernaut on the mound? The obvious points are the changes in arm slot and velocity, as evidenced below:

The vertical release point (final graph) seems to sneak back to his career norms towards the end of the season, but the horizontal release point (middle graph) gives the impression that you’re comparing two completely different pitchers.

Shannon Drayer wrote about these arm slot changes and their results almost immediately after Paxton was recalled:

Six innings of five-hit ball, including 10 strikeouts and just one walk against a red-hot Indians team, was quite a statement from Paxton, who had failed to secure the fifth spot in the rotation in spring training. Hitting 100 mph on the radar gun several times Monday was the exclamation point. Paxton has put in good work in Triple-A, which included a change of mechanics that brought him closer to a three-quarter arm slot rather than the more over-the-top delivery we had seen from him.

Throwing 100 mph is fun. It gets the crowd into it and hitters have like a billionth of a second to react and it’s just really damn cool, but generally, starting pitchers capable of hitting triple-digits aren’t getting by solely on this ability. Syndergaard has his slider. Sale has his changeup, slider, and wacky wailing inflatable arm flailing tube man mechanics. Yordano Ventura has his winning attitude.

Enter James Paxton’s cutter:

His cutter, in the sense that it was a pitch he threw that behaved like a cutter, wasn’t new. He threw it <100 times in 2015, but he most definitely had a cutter. The difference between his 2015 and 2016 cutter, however, was substantial. Take a look at these numbers I’ve compiled from Fangraphs:

In 2015, his cutter produced the third-worst value for a cutter in all of baseball. A year later, he finished fourth, behind only Yordano Ventura (who threw it a grand total of 51 times), Mike Montgomery, and Mat Latos. And while one can easily argue the cutter’s 2015 value due to the small sample size, we can still definitively say A) he had one and B) the quality of it was poor enough that he never seemed to be willing to throw it. A year ago, it clocked in as his least-valuable pitch by a substantial margin (-6.44 runs). In 2016, it ranked as his best pitch by a substantial margin (+2.83 runs).

Now, this wasn’t a weapon so deadly that he threw it a bizarre amount. The 15.7% usage is still relatively low, but the development of his cutter is the primary reason he posted career-lows in fastball-usage (62.4%) and curveball-usage (13.7%) in 2016. His fastball usage was down a full eight percent from 2015.

It’s not just a newfound velocity or movement on the pitch that’s making it effective, either. Paxton has commanded the pitch as well as he’s commanded anything:

He’s done a tremendous job peppering the edges while avoiding both the top and the right side of the strike zone.

Paxton’s career has been heavily burdened by inconsistencies. From year to year, it’s been incredibly hard to determine concrete expectations for the big lefty. If he manages to carry this cutter into 2017, however, he becomes all the more intriguing as a potential top of the rotation starter. This cutter makes him versatile. This cutter makes him dangerous. For the Mariners’ sake, may he carry it with him wherever he goes.