Pirates' Seth Hernandez Putting Together Stellar Pitch Mix

Hernandez can throw his four-seam fastball up to 100 mph and is averaging 97.3 mph so far, but is also getting good velocity on his slider, 88.4 mph, while getting more expected velocities for his curveball and changeup.

These five starts have seen Hernandez rely mostly on his four-seam fastball, throwing it almost 50% of the time, but also throwing his offspeed pitches the other half, mixing them all up about evenly.

Why It is Working for Him So Far

Just having these pitches isn't why Hernandez has excelled in his first five starts, it's how he's using them that make them so dangerous.

The four-seam fastball usage means hitters are generally waiting for it, as he has a lower whiff rate on it, but this allows his offspeed pitches to work far more effectively, especially in a strikeout situation.

Hernandez has a 70% whiff rate or higher on his offspeed pitches and 33 combined strikeouts on them as well.

A big reason for those high whiff rates is the movement that Hernandez generates on his offspeed pitches, relying on big breaks and drops that baffle Single-A hitters.

Hernandez is getting a big drop on his curveball, more than 50 inches in each start, while his slider and changeup are each dropping about 30 inches or so as well.

Pirates catcher Rafael Flores Jr. who caught Hernandez this offseason described his changeup as a "parachute" with how it comes out of his hand and just drops down into the catcher's mitt.

One other thing that Flores noted was the confidence with which Hernandez pitches, showing maturity far beyond his age and having the talent to do that as well, which makes him so special.

"He can throw wherever he wants," Flores said on Hernandez. "The heater, changeup, curveball, slider, everything, he can throw where he wants. And for him being 19 only, being able to do that is insane."