When you picture a prototypical Major League pitcher, someone like Nestor Cortes is the last person you'd think of. But he's become baseball's most unlikely ace.

The Yankees' 5-foot-11 left-hander has gone from a journeyman who the Yankees let go to another team twice to the American League ERA leader. He has a 1.41 ERA and 42 strikeouts in 32 innings entering his start in Sunday's series finale against the White Sox. He almost threw a no-hitter this week. He threw an immaculate inning. And he's earned the nickname Nasty Nestor.

How did he do it? Here are four reasons why Nasty Nestor got so nasty.

The scattershot release points

Normal pitchers throw the ball from the same arm slot over and over again. Not Nasty Nestor. He throws pitches from every arm angle you can think of.

Here are Cortes' release points for 2022.

Look at how much area that covers. Here's the full range of his release point, both vertical and horizontal.

• Highest release point: 6.26 feet
• Lowest release point: 4.57 feet
• Most over-the-top release point: 0.51 feet from the center of the rubber
• Most sidearm release point: 3.20 feet from the center of the rubber

The difference between Cortes' highest and lowest vertical release points of the season is 1.69 feet. The difference between his most over-the-top and most sidearm horizontal release points is 2.69 feet.

He varies his release points with all of his pitch types, too. His fastball release points have a range of over two feet horizontally, and over a foot vertically. His cutter release points have a range of about a foot both horizontally and vertically. His slider release points have a range of about a foot and a half horizontally and vertically. Nothing comes from the same place every time.

Check out some of the strikeouts Cortes has collected with his different arm angles:

• He punched out Nicky Lopez on a sidearm sinker with a horizontal release point 3.16 feet to the first-base side of the rubber.
• He rang up Adolís García on a true four-seamer with a horizontal release point of 0.65 feet, basically straight above the rubber.
• He fanned Corey Seager on a drop-down slider that came from a vertical release point just 4.65 feet off the ground.
• He whiffed Robinson Chirinos on an over-the-top cutter with a vertical release point that was 6.02 feet high.

The Yankee cutter

One of the keys to the Yankees' pitching staff this season has been their widespread adoption of the cutter. Gerrit Cole has added a cutter. Luis Severino has added a cutter. And Cortes has added a cutter. 

Cortes never threw a cutter before 2021 -- not in his debut season with the Orioles, or his first stint with the Yankees, or his brief time with the Mariners. But when the Yankees got him back, he added a cutter to his repertoire. And now it's his most-used pitch. 

Cortes' cutter usage by season
2018-20: 0%
2021: 23.6% 
2022: 40.7%

Cortes' cutter comes in at an average velocity of 85.6 mph and gets above-average vertical and horizontal movement, dropping 0.8 inches more than an average cutter and breaking 2.3 inches more than an average cutter. 

The results have been great so far. Opponents are batting just .137 (7-for-51) and slugging .294 against Cortes' cutter, and he's gotten more swings-and-misses (34) and strikeouts (20) with it than he has with any other pitch type. 

That's already more cutter K's than Cortes had all of last season (16), when the majority of his strikeouts came on his fastball. Hitters also batted .271 and slugged .447 against the cutter last season, and didn't swing and miss as much (22.6% whiff rate last season, 28.6% this season). Cortes' cutter is just a better pitch in 2022.

The sweeping slider

The "sweeper" style of slider is the trend in baseball in 2022 -- sliders with a more horizontal movement direction -- and the Yankees are using it, too. They call it the "whirly."

New York pitchers like Lucas Luetge -- and Cortes -- have added tons of sweep to their slider. 

Look at how the average horizontal break on Cortes' slider has changed over his time in the big leagues. 

2019 (first Yankees stint): 5.4 inches 
2020 (Mariners): 6.1 inches
2021 (back to Yankees): 14.5 inches
2022: 16.2 inches

Cortes' slider is breaking over 10 inches more than it was the first time he was on the Yankees, and he's even added close to two inches of break from last year to this year. 

He's taken some velocity off the pitch (his slider velo has gone from 81.5 mph to 80.9 mph to 77.4 mph to 76.2 mph from 2019-22) and emphasized the movement instead. 

Cortes' slider is more of a complementary pitch to his fastball and cutter (he throws it 13.7% of the time), but a pitch with 16-plus inches of movement is a good extra piece to have.

The deceptive rising fastball

Cortes makes his living on deception -- the array of arm angles, the altered timing of the delivery and so on. And his fastball fits right in with that theme.

Cortes doesn't throw hard -- his four-seamer only averages 90.4 mph -- but the way he throws it actually gives it the "rising fastball" effect that makes it sneak up on a hitter.

Hitters are batting .206 (7-for-34) and slugging .239 against Cortes' four-seamer this season, with 13 strikeouts. They're not squaring it up well at all -- based on the quality of contact against Cortes' fastball, those hitters have an expected batting average of just .163 and an expected slugging percentage of just .235.

How? Despite its low velocity, Cortes' fastball gets +2.9 inches of "rise" above average. It's not an explosive rising fastball like his teammate Cole has, but it's a deceptive rising fastball that can carry past a hitter.

Cortes' fastball has dropped less and less season by season. He gets that "rising" effect because he throws a true four-seamer. The spin axis on the pitch is almost straight backspin: 11:30 on a clock face, where 12:00 would be the truest four-seamer. Cortes gets 94% active spin on his four-seamer, which means almost all of its 2,299 rpm spin rate contributes to the movement on the pitch.

That's how a fastball that barely breaks 90 mph can be such an effective pitch. Add that to the cutter, slider and deception, and you get Nasty Nestor.