Felix Hernandez’s changeup is one of the best pitches in baseball. How can we actually know this? You could, if you wanted, look at the assigned run values. Those’ll tell you what happened on Felix’s changeups, specifically. But, those run values get complicated, since all pitches are inter-related. One pitch has an effect on another pitch, even if it’s of a different type. Yet there’s a very simple solution to this. How do we know Felix’s changeup is amazing? Felix is amazing, and he uses his changeup a third of the time. So it stands to reason the latter has a lot to do with the former.

A year ago, I was talking to a major leaguer, and when we somehow got to the topic of Henderson Alvarez, the player remarked that Alvarez seemed like he was one little tweak away from becoming a superstar. That much is easy to understand — Alvarez is still very young and he still throws very hard, and all of his pitches have life. It’s easy to see the upside in Alvarez’s repertoire. Maybe he’ll never reach his ceiling, but because of his ability, his ceiling is higher than almost all others.

I was reminded in my chat earlier today that Alvarez has something in common with Felix. Actually, he has a lot of things in common with Felix. That would be another indication of Alvarez’s upside. If you’ve watched Alvarez, and thought to yourself he has an ace’s arsenal of pitches, you haven’t been wrong. He just hasn’t yet made the most of it.

I wanted to have a little fun with the Baseball Prospectus PITCHf/x leaderboards. The goal was to compare pitches to Felix Hernandez’s pitches, so I isolated right-handed starters in 2014, and looked at pitches thrown at least 100 times. I narrowed categories down to velocity, horizontal movement, and vertical movement, and — using z-scores — I calculated differences between different pitches and Felix’s pitch. I started to see a lot of Henderson Alvarez’s name.

Take sliders, for example. Alvarez throws his slider in the mid-80s. Ditto Felix. The movements are comparable. Alvarez is separated from Felix’s slider by 1.9 total standard deviations. This ranks his the fifth-most comparable slider, out of 96 candidates.

Move on to four-seam fastballs. Alvarez is separated from Felix’s four-seamer by 1.2 total standard deviations. This ranks his the ninth-most comparable four-seamer, out of 153 candidates.

Sinkers? Alvarez is separated from Felix’s two-seamer by 0.8 total standard deviations. This ranks his the third-most comparable sinker, out of 120 candidates.

And at last, we arrive at the changeup. Alvarez is separated from Felix’s change by 0.6 total standard deviations. This ranks his the first-most comparable changeup, out of 87 candidates. The next-closest is more than twice as far away. Felix averages a 90mph changeup. Alvarez averages a 90mph changeup. Both of them have the same tail. Both of them have almost the same sink. That Felix change is one of the league’s truly outstanding pitches. Its signature characteristic is being hardly separated at all from the fastball. Alvarez is as close a comp as you’ll find. The rumors are true: Henderson Alvarez throws Felix Hernandez’s changeup.

And it’s not an accident. From Juan C. Rodriguez:

Typically, pitchers strive for a 10-mph differential between their fastball and change. Alvarez used to be among those. During a game against fellow Venezuelan Felix Hernandez in 2012, Alvarez took note of his changeup velocity. “I told myself, ‘He throws his changeup 90-91, I can do the same thing,'” said Alvarez, whose fastball per PITCHF/x averages 93.6 mph, just 4.6 mph faster than his average changeup velocity. “From that time I started throwing it harder and it’s given me good results. It’s a hard changeup, but if it has a lot of action it’s good, too…The change and the sinker are my two biggest strengths. Without them I’m not a pitcher.”

From Brooks Baseball, here are Alvarez’s relevant pitch velocities before and after that game opposite Felix:

Pitch Before, mph After, mph Four-Seam 94.8 94.7 Sinker 93.8 94.0 Changeup 86.6 89.6

It really did just click. Alvarez has thrown the same fastball, and the same sinker, but he’s kicked up his changeup a full three miles per hour. And it’s not like Alvarez was working on some lousy, tertiary offering; his changeup was a scout favorite as he advanced through the minors. Observers liked Alvarez’s change. Then he tweaked it to be more like Felix.

And, just last season, Alvarez finished with a 2.65 ERA in almost 200 innings. That’s promising, and a hell of a lot better than what Alvarez did in an abbreviated 2013. Yet, obviously, Henderson Alvarez isn’t Felix Hernandez. Alvarez finished with almost league-average peripherals; Felix nearly won the AL Cy Young. Alvarez, for whatever it’s worth, generated slightly worse-than-average results with his changeup. Felix’s change was almost 25 runs better than average. By pitch characteristics, Alvarez’s change and Felix’s change are one and the same. So why doesn’t Alvarez’s change measure up?

Usage Patterns

Here’s the simplest way to look at this — for 2014, some changeup rates:

Split Alvarez Hernandez Overall 21% 32% RHB 12% 33% LHB 29% 31% RHB, 2 strikes 24% 55% LHB, 2 strikes 36% 36%

Now, this doesn’t explain the results. If anything, the results explain what you see above. But think of these as indicators of trust, along with usage. Against lefties, Alvarez throws just as many changeups. Against lefties with two strikes, it’s the same story. Against righties, though, they almost couldn’t be more different. Felix throws a few more changeups to righties than he does to lefties, which is unusual for any right-handed pitcher. Alvarez trims his changeup usage against righties to roughly one per eight pitches. With two strikes, the split is also large: for Felix, the change is a putaway pitch. For Alvarez, it’s one out of four. Felix uses his changeup a lot more against right-handed hitters. So, he has a lot more confidence in it against right-handed hitters. Alvarez, perhaps, should throw his changeup more. Or, there are reasons why he hasn’t yet. We continue!

Release Point Consistency

This is going to be a little less intuitive, but the numbers in this table are in units of feet. Again, this is for 2014. H refers to horizontal release point, where a negative number means the pitch was released that many feet toward the third-base side of the middle of the rubber. V refers to vertical release point, and that number means the pitch was released that many feet above the rubber.

Pitch Alvarez, H Alvarez, V Hernandez, H Hernandez, V Four-Seam -2.07 6.52 -2.21 6.22 Sinker -2.15 6.44 -2.28 6.19 Changeup -2.36 6.30 -2.23 6.16

Maybe it would help to look at the Felix side first. You see incredible consistency in the fastball, sinker, and changeup release points. The spread in horizontal release is less than an inch. The spread in vertical release is also less than an inch. Now look at Alvarez. The spread in horizontal release is more than three inches. The spread in vertical release is almost three inches. All these pitches are supposed to be thrown from the same angles, with the same motions. That’s a big part of what makes a changeup so deceptive — out of the hand, it looks like a fastball. Alvarez’s release points haven’t been wildly inconsistent; he just hasn’t disguised his changeup as well as Felix. The arm has dropped a little bit, relative to the fastballs, and if Alvarez had his way, this wouldn’t be the case.

I’m not suggesting that hitters can pick up on a difference of a couple inches from 60 feet away. Maybe they can and maybe they can’t, but what this implies is just that Alvarez’s overall throwing motions are more different than Felix’s are, between pitch types. Alvarez doesn’t perfectly mirror his own mechanics, so it makes sense that his changeup would perform worse than one of the best changeups anywhere.

Location

Here, the differences stop being subtle. This is a table of average vertical pitch locations. The numbers are in units of feet, where 0 refers to the vertical middle of the strike zone. So, a positive number means a pitch was usually in the upper half. A negative number means a pitch was usually in the lower half. Comparing, again, fastballs and changeups:

Pitch Alvarez Hernandez Four-Seam 0.10 -0.15 Sinker -0.30 -0.41 Changeup -0.60 -1.25

Alvarez’s average changeup was almost eight inches higher than Felix’s average changeup. The changeup, as you know, is a pitch you want to keep down, at the lower edge of the zone or below. That’s not always true, but that’s usually true, and an elevated changeup tends to be a mistake. More importantly, look at the separations between sinker heights and changeup heights. Alvarez’s average changeup was lower than his average sinker by fewer than four inches. Felix’s average changeup was lower than his average sinker by more than 10 inches. That’s how you get hitters to swing over the top of a change if they misidentify it as a two-seamer. With less of a gap, a hitter can still make contact by focusing on the same area.

A much simpler changeup table:

Location Alvarez Hernandez In Zone 39% 21% Out Of Zone 61% 79%

As suggested by the first table, Alvarez throws a lot more changeups in the strike zone. That’s fine, sometimes, but it’s often not the intent. The two pitches get about the same number of swings, more or less, but in Felix’s case, there are more swings at balls, which is the perfect outcome for a pitcher.

Let’s isolate just strikeout situations, so, here are two-strike frequencies:

Alvarez: 45% changeups low, below the zone

45% changeups low, below the zone Hernandez: 73%

Felix has been a master of burying his changeup where hitters can’t do anything with it. Alvarez, not so much. When things go right, this happens:

But, the numbers speak for themselves. Against Alvarez’s two-strike changeups last year, opponents batted .188. Against Felix’s, .057. It’s not that Felix never makes mistakes — he did allow four two-strike changeup home runs — but usually, with a changeup, Felix doesn’t give the hitter much of an opportunity. Hitters against Alvarez’s change have more of an opportunity. He doesn’t bury it nearly so much, and he throws it pretty close to where he throws his sinker.

By the usual identifiers, Henderson Alvarez essentially throws Felix Hernandez’s changeup. Which is extra interesting, because he also almost throws Felix’s four-seamer, two-seamer, and slider. Yet there’s throwing a pitch and there’s using a pitch, and while Alvarez’s changeup behaves like Felix’s, generally, it doesn’t quite behave the same, specifically. Alvarez’s throwing motion is a little different, and his locations are a little different, and because of this or perhaps not because of this, Alvarez doesn’t throw his changeup nearly so much against same-handed hitters. At the same time, you can see the promise in Alvarez, and you can see the gap between where he is and becoming an ace.

The good news: Alvarez isn’t yet 25. He’s a little over three years into his big-league career. Felix says that he mastered his changeup in 2009, when he was a little over three years into his big-league career. Henderson Alvarez, already, is a perfectly useful groundball starting pitcher. But he remains just one or two little tweaks away from becoming a superstar.