After an absolutely dominant April and May for the Yankees, where Nestor Cortes posted a 1.70 ERA and 30.2% K%, Nasty Nestor hit a skid in June. His ERA was a mediocre 4.15, and his 5.08 FIP was alarming. Furthermore, Cortes had a K% under 23%, meaning more batted balls for hitters creating a scary 2.03 HR/9 that month. The pitch of concern was his cutter, which had a .365 wOBA and .595 SLG% against, and it seemed as if Cortes had been figured out.
Yankee starters across the board got their cutters crushed in the month of June, a scary trend that created adjustment periods for everyone, with some still trying to sort it out, like Jameson Taillon. Gerrit Cole rebounded nicely in Seattle, Severino has not returned from the IL, Montas is looking to bounce back against Boston, but Cortes is already ahead of the curve. The one with the least appealing “stuff,” the one who was never a highly coveted prospect, the constant underdog, Cortes has once again found himself leading this pitching staff.
The league adjusted to Nestor Cortes, so he’s now returning the favor and mixing things up.
Aggressive Fastball Usage
Against the Rays in late May, Nestor’s in-game fastball velocity reached a season-high, and it maintained ever since, but it didn’t change the ugly results he’d end up getting just weeks later in a blow up start versus Minnesota.
Against the Mariners, Nestor was able to blow fastballs by hitters, and that’s due to greater aggression in the zone with elevation. Nestor’s 19.6″ of Induced Vertical Break gives him natural ride up in the zone, and while it doesn’t mean you only throw fastballs up in the zone, it does mean that it plays up in the zone where hitters will be more likely to expand above the zone or swing and miss more.
This change has reflected in his strikeout rates, generating a 36.0% K% and just a .240 wOBA since the start of July on his Four-Seam Fastball. That level of excellence on the pitch re-establishes his primary pitch and gives him the ability to pepper the strike zone, get swings and misses, and work effectively. It’s back to being one of the best fastballs in the sport results wise, ranking in the top 10 among all pitchers in Four-Seam Run Value (via Baseball Savant)
With Nestor Cortes adjusting his fastball usage, how have his secondary pitches been realigned to help tunnel and generate whiffs and soft contact?
Cut Down on Cutters, Slide In the Sliders
Nestor Cortes’ Cutter began causing problems for the southpaw, as his it got worse progressively after a hot start with the pitch in Spring.
- April: .197 xwOBA
- May: .272 xwOBA
- June: .309 xwOBA
- July: .351 xwOBA
- August: .402 xwOBA
xwOBA is Expected Weighted On-Base Average, a metric that takes into account the quality of contact alongside strikeouts and walks. Scaled like OBP, lower for pitchers is better, seeing it balloon is not a great sign. Cortes’ Cutter had regressed. This just wasn’t a pitch Nestor could keep using as much as he had if he wanted to continue his successful season, he needed to find a new secondary pitch.
Nestor Cortes has always had more of a sweeping Slider, a pitch that generates a lot of horizontal movement and typically should be a high whiff pitch. Cortes didn’t get a ton of whiffs and strikeouts on his at first, but he began using it more instead of his Cutter, and it yielded great results.
The two pitches swapped usage, with the Slider being used more and the Cutter being used less. His slider has generated a .164 wOBA and 21.4% K%, filling in nicely as Nestor’s secondary pitch. What’s even more encouraging is the increase in whiffs as Nestor has used the Slider more and more. It’s a matter of comfort with the pitch, and I imagine as he uses it more and more, it’ll be greater in it’s effectiveness.
Nestor Cortes Is Setting the Tone For Pitchers on the Yankees
Nestor Cortes has posted a strong 2.45 ERA and 26.3% K% in his last 5 starts, leading the way for this struggling Yankee squad. His ability to remain successful and dominant on the mound could help set the tone for the Yankees as they try to find their way to synch up their great outings and great offense to win ballgames. They’re always one big pitch and one big hit away from going on a tear, and the leadership of Cortes to be the ace of this staff when other guys are struggling speaks volumes as to how important he is for this Yankee staff.
From 36th Round Pick to arguably the Yankees’ best starter this season, it’s no surprise that the second the league starts to get a hold of Nestor Cortes, he checkmates them and makes the adjustments needed to keep shoving. His magical 2022 season has a new horizon, and he’s geared up to have a strong finish to the season as he looks to take on the next challenge of his postseason debut.