Remember when Nestor Cortes stunk?
Nestor Cortes has emerged as one of the very best pitchers in MLB. He's second in the American League in ERA (1.50) and bWAR (2.6). It's no longer a surprise or small-sample-size mirage. He's a legitimate ace. This is because he has figured out the secret to pitching. It really isn't very complicated:
Throw more innings.
Give up fewer runs.
Grow better facial hair.
This is like saying robbing a bank is as simple as going into the building and walking out with a bag of money, but that's equivalent to what Cortes has accomplished. From 2018-2020, he surrendered 62 runs in 79 innings. Since 2021, he has only allowed 43 runs in 153 innings, including just 11 in 60 this season.
He accrued most of his ugly early-career numbers as a member of the 2019 Yankees. Nestor wasn't a memorable member of that 103-win club, but he threw 66.2 innings over 32 relief appearances and one start. He posted a 5.67 ERA that season with 16 home runs allowed. His 2.2 HR/9 was the second-worst in MLB among qualified relievers. The Statcast percentile rankings weren't pretty:
His pitch arsenal wasn't quite the same as it is now. Notably absent was his devastating cutter, which he throws 40% of the time in 2022. He didn't incorporate that pitch until last season. He primarily featured a four-seamer/slider/changeup mix in 2019. His slider in particular illustrates the difference between control and command. Here's his slider heat map from 2019:
By contrast, this is where he locates his slider in 2022:
Having control is merely the ability to avoid walks. Cortes did that in 2019 but frequently left pitches in the middle of the plate which could be blasted over the fence. In 2022, he displays outstanding command by dotting the outside corner against right-handed hitters. Here's an example of what happened to those middle-middle hanging sliders in 2019:
https://sporty-clips.mlb.com/8e57571a-1fad-4f33-abc2-889793cb8ecb.mp4
Of course, it wasn't just the slider's fault. When he threw this 88 mph fastball in Rougned Odor's wheelhouse, it landed 440 feet away for a grand slam:
https://sporty-clips.mlb.com/2f33e886-9c58-40b3-aab7-d28151929a44.mp4
This changeup down the pipe hardly moved at all, which might be why he barely ever throws it these days:
https://sporty-clips.mlb.com/ce9ff083-af29-4120-8513-667cd6c7dad8.mp4
We're all grateful Cortes isn't that guy anymore. The new-and-improved Nestor locates his pitches in places that are nearly impossible to hit. That's why his WHIP dropped from 1.55 in 2019 to 0.87 this year and his home run rate is more than three times lower.
Of course, the real major change he made was the mustache. He just doesn't look right clean-shaven, but it was still better than whatever this was:
https://twitter.com/mlbtraderumors/status/984961800369311744
The new Nestor is here to stay. As long as he keeps locating his pitches flawlessly on the outside corner, the only questions will be whether or not he should start the All-Star Game and if he can win the Cy Young.