James Paxton is heating up

Maybe James Paxton was the key starter the Yankees acquired at the deadline. His five starts since the deadline passed have been in line with the results many Yankee fans expected of the Big Maple and are hands-down the best he’s produced since his knee injury earlier this year. Paxton’s success has a lot to do with his altered pitch usage, and with the playoffs right around the corner, his successes couldn’t have come at a better time.

James Paxton’s fastball has been -- and probably always will be -- his bread and butter pitch, In 2019, he throws the pitch just over 60% of the time. No starter in the league throws more fastballs by percentage (minimum 2,000 pitches). What makes that fact shocking is that Paxton is throwing fewer fastballs this season than in any of his prior seasons as a big leaguer.

Predictive statistics tell us the fastball is still an effective pitch. There have only been minor fluctuations in his fastball expected batting average, expected slugging, and expected wOBA on contact from 2018 to this season, but those figures have taken a step back since Paxton’s breakout 2017 season. Plus, predictive statistics can only tell us what should be expected, and aren’t necessarily a reflection of actual performance. It’s in the latter category where the fastball-heavy approach has failed J-Pax.

Hitters have a .290 batting average, a .532 slugging percentage, and a .383 wOBA against the fastball in 2019. To be fair, Paxton’s battled (and likely pitched through) a left knee injury in 2019 and probably isn’t physically 100%, but those numbers are not good.

In recent starts, Paxton has backed off the fastball in favor of his curveball in particular, and the results have been more favorable. Since August 2nd, his fastball usage has dropped to about 50% of the time, and his curveball usage is up to around 25%, nearly doubling his curveball rate in July.

The curveball itself has been an extremely effective pitch. Hes generates whiffs at a 46.6% rate with the pitch, and when hitters do make contact, it’s not usually very effective. They’re slugging just .310 and own a .240 wOBA against the pitch.

More curveballs have kept hitters guessing in all other counts too. His fastball usage has gone down, and FanGraphs’ pitch weights suggest it’s a better pitch than before. Paxton’s cutter has had a dip in exit velocity but also has seen an increase in whiffs despite no different movement or velocity.

In his last five starts, Paxton has thrown 30.1 innings with a 3.56 ERA while striking out 35 and walking nine. Technically, that rate of strikeouts is lower than his season average of 11.40 K/9, but his swinging strikes are up about two points to 16.4%. That rate is good for fourth in the big leagues behind only Jacob deGrom, Lucas Giolito, and Justin Verlander -- good company to be in for sure.

The last five starts represent the most sustained success he’s had all year long, and it culminated in Friday night’s start against the Dodgers. He got 29 swings-and-misses on 109 pitches, many coming off the curveball. Here’s some video:

James Paxton is finding more success now than he’s had pretty much all year long and definitely since his knee injury. Throwing more curveballs and fewer fastballs has definitely played a part in that success. No doubt, Paxton’s fastball will always be his best pitch, but the curveball is working right now. Hopefully he’ll ride this success through the rest of the season and well into the playoffs.