Cueto's fastball among most difficult to hit hard

We can go back and forth forever about whether Johnny Cueto "is an ace" or not, or whether he was correct in turning down $120 million from Arizona, as MLB.com's Steve Gilbert reported he recently did. (From this view: close, and probably, particularly without a qualifying offer.) But what we do know is that for most of his career, Cueto has found tremendous success not by missing a ton of bats, as so many of his colleagues have done. He's done it by making sure the contact he allows is the kind of contact he wants.

For years, that's something that's either been measured anecdotally, by onlookers attempting to make judgment calls on the types of contact allowed, or from extrapolating other data. But now, of course, we have Statcast™, and so we can actually put numbers to this.

In Statcast™'s first year, it certainly looks promising that perhaps limiting exit velocity is a skill elite pitchers have, at least judging by the fact that the four best pitchers (minimum 1,400 pitches) at it are Clayton Kershaw, Jake Arrieta, Noah Syndergaard and Dallas Keuchel, indisputably four of the sport's most elite arms. The worst mark was from Justin De Fratus, who had a 5.51 ERA. We don't know how this will hold up over several years of data, but in the first year, this is as expected. Hard-hit balls get hit, hard.

Cueto comes in just outside the top 10 of these 153 pitchers, finishing 11th with a mark of 85.6 mph, which is indeed very good. It backs up what we thought we knew about him in the pre-Statcast™ era. From 2012-14, according to FanGraphs, he led baseball with the lowest percentage of "hard-hit balls," and while that's not the same thing as Statcast™ radar tracking technology, it passes the sniff test. 

Still, let's dig deeper. That number includes Cueto's offspeed pitches. What if we just isolate his two-seam and four-seam fastballs, two offerings that combined for more than 51 percent of his pitches in 2015?

Four-seam exit velocity leaders (minimum 600 pitches, 149 qualified)
1. Arrieta -- 84.4 mph
2. Cueto -- 85.4 mph
3. Kershaw -- 85.6 mph

Two-seam exit velocity leaders (minimum 400 pitches, 76 qualified)
1. Mark Buehrle -- 86.2 mph
2. Cueto -- 86.3 mph
3. Keuchel -- 86.4 mph

Now we're talking. Those are some names, along with perhaps a bit of an explanation for how the ageless and soft-tossing Buehrle managed to survive that long. Long his calling card, Cueto's pair of fastballs allowed just a .227 batting average this year and only six homers on 1,886 pitches. (He's added a cut fastball in recent years as well, though its exit velo numbers are unremarkable one way or the other.)

At least somewhat surprisingly, there's actually not necessarily a very strong relationship for all pitchers between exit velocity and Batting Average on Balls in Play, because it's crucial to include launch angle and direction too, to say nothing of defense and luck. But despite that, Cueto over the past several years had seemingly figured out a way to make that skill stick, with incredible consistency.

In 2013, Cueto had a .236 BABIP (albeit in only 11 starts, due to injury). The next year, it was .238. Through 19 starts in 2015 before being traded, it was .234. It doesn't get more consistent than that, and with the MLB-average BABIP being .294 in that time, it was considerably better than most big league pitchers. But with the Royals, that BABIP jumped to a shocking .343, which, along with a lowered strikeout rate, was the source of all of Cueto's issues. More balls found grass than gloves.

So, you may think, based on how inconsistent and frustrating he was with the Royals, that Cueto's excellent fastballs suddenly got hit hard with Kansas City. But that's not necessarily true. If anything, his changes were with everything else:

The slight differences in Cueto's four- and two-seam fastballs weren't much. His cutter got hit a bit harder. Cueto's slider was actually better with the Royals, at least as far as how hard it was hit. But that changeup really fell apart, with real evidence of less downward movement keeping it flat, as his spin rate increased by 150 rpm on the pitch with Kansas City. (Higher spin is correlated with pitches staying higher, which is great for four-seam fastballs, and often less so for changes.)

Of course, all of Cueto's pitches were hit harder as a Royal, even if they weren't hit harder. What we saw was a pitcher out of sorts, at least until a historic shutout in Game 2 of the World Series (the first Fall Classic complete game by an American League pitcher in 24 years). There's just not one easy answer to point to for what happened to Cueto for much of his time as a Royal.

So we're left with the same question as every team in baseball must have, the question that the Diamondbacks have apparently found comfort with. Was Cueto's Kansas City BABIP explosion simply a result of bad luck, or catcher miscommunication, or a change in approach, or some combination of all of it, some short-term thing that's easily fixed as we saw in the World Series? Or is this evidence that truly no one can beat the BABIP gods forever, good exit velocity or not? Well more than $100 million hinges on the answer.