Jacob Nix's unique changeup could prove to be devastating, considering his high-octane fastball

When Jacob Nix threw the first changeup of his big-league career last Friday night against the Phillies, Statcast initially registered it as a curveball. Just his third pitch of the game, give MLB’s pitch-classifying algorithm a break. An 81.2 mph offering to César Hernández, the changeup in question came in north of 13 mph slower than Nix’s first two fastballs, which averaged a cool 94.7 mph.

Take a look at the average pitch speed around the league in 2018, per Pitch Info.

Working with little information, Statcast erroneously classified Nix’s changeups as curveballs because — by speed alone, at least — they looked more like curveballs than changeups.

On the night, Nix ended up tossing a dozen changeups that averaged 81.4 mph, with his fastest one traveling at 83.5 and his slowest at 79.9, according to Brooks Baseball. Nix also maintained his fastball velocity throughout the game, averaging 94.4 mph. Out of his 19 hardest fastballs — he topped out at 96.5 on his fourth pitch — 14 came in the first inning, with the other five being delivered in his final frame, the sixth. In between, he sat in the 93-94 range.

On average, Nix threw his changeup 13 mph slower than his fastball. Does anyone (outside of Bugs Bunny, anyway) possess that large of a speed differential between the two pitches? Well, no — not among regular starters in 2018, anyway.

Among the 147 starters with at least 30 innings and a 5 percent or higher changeup usage rate, only 15 have posted speed differentials bigger than 10 mph so far in 2018. While the four listed alongside Nix above hardly qualify as a Cy Young-caliber quartet, the 10-and-up group also features Max Scherzer, Luis Severino and Tyler Anderson.

Does the speed gap mean Nix’s changeup is likely to be better than the average one, though? It might.

As you can see, the group of pitchers with a large speed differential between their fastball and change have gotten more whiffs this season, while pitchers with a small differential have induced more grounders. Note the last two columns, which are FanGraphs’ pitch-specific linear weights for the changeup and fastball. In both categories, the large-differential group prevails, perhaps a credit to the better interplay between the two pitches. (The large-gap group also has better numbers than the middle tier in those last two categories, in case you were wondering.)

The results seem to jibe with much more rigorous past research. In 2013, Harry Pavlidis found that both fastball speed and FB-CH speed differential lead to higher whiff rates (at the expense of groundball rate) for the changeup. To go along with a league-best differential, Nix’s 94.4 mph fastball is more than one mph higher than the league average for starters and would rank in the top third of the league if he had enough innings to qualify. Nix has both factors in his favor, which could turn his changeup — often ranked behind his curveball by scouts — into a true swing-and-miss secondary option.

Let’s take a look at some of Nix in action.

First, a fastball to the Phillies’ best hitter, Rhys Hoskins:

Then, on the following pitch, a changeup:

OK, so there’s another thing that makes Nix’s changeup interesting.

In Pavlidis’ research, he also found that a large gap between a pitcher’s vertical fastball and changeup movement correlated well with whiffs. In fact, it correlated better than either fastball speed or FB-CH speed differential. Sure enough, Nix’s 7.7-inch movement differential ranks 33rd out of the 555 pitchers to throw at least one four-seam fastball and one changeup this season, in the same range as pitchers like Zack Greinke, Carlos Carrasco and Scherzer.

Note how Nix dots the up-and-in corner with the 1-1 fastball. To that point, Hoskins had seen seven fastballs and three curveballs in his three at-bats. Righty on righty, he probably wasn’t sitting on a two-strike changeup, a pitch he sees only 11 percent of the time in that situation. Nix threw it, and for a split-second, Hoskins probably assumed it was a heater headed for the middle part of the plate. Then it slowed down and dropped off the table, inspiring only a foolhardy hack from Hoskins.

Nix pulled out all the stops in his final inning. Going into the sixth, he had started batters with 16 fastballs and five curveballs — not a single changeup led off an at-bat. In the sixth, he started both Carlos Santana — he threw five of his 12 changes to the switch-hitting Santana — and Odúbel Herrera with changeups. Herrera, gearing up for a mid-90s fastball, nearly screwed himself into the ground when Nix delivered him a first-pitch changeup at 81.1 mph.

It was only one start, of course, and Nix has questions to answer in start No. 2 and beyond. Can he continue to command his fastball well, hitting the edges of the strike zone? Will his curveball — which didn’t coax a whiff on Friday — become more effective? And can he maintain deceptive arm action on such a slow changeup, avoiding some of the common pitfalls of his slow change comrades?

There’s only so much we can learn from 12 pitches, but thanks to baseball’s pitch-tracking technology, we can already identify that Nix has a unique changeup. Combined with a high-octane fastball, it could help him cement a position in the middle of a soon-to-be-crowded Padres rotation.

(Top photo by Jake Roth/USA TODAY Sports)