Thanks to the work of pioneers of defensive independent pitching statistics like Voros McCracken, we know an awful lot about what goes into making a successful pitcher. Ground balls are good, because they don't turn into home runs; those are bad. Strikeouts are good, because they generally don't lead to base runners, and walks are bad for precisely the opposite reason.
Those three facets of pitching make up a lot of the advanced pitching stats, because they make up a bulk of what pitchers can control. Generally speaking, pitchers don't have much control over what happens to a ball once it is hit into the field of play, so keeping it out of play is of paramount importance, as is keeping it on the ground.
Generally speaking, defensive independent pitching stats do a pretty good job of matching up with what a pitcher actually ends up producing. Between 2013 and 2014, there were 169 pitching seasons that qualified for the ERA title, and 160 of them featured an ERA within 0.95 runs of the FIP either way; that's 94.7 percent.
I chose 0.95 runs because it represents the margin by which Reds starter Johnny Cueto has outperformed his FIP since the start of the 2013 season. His 3.41 FIP is a fine mark, good for 30th among all starters in that span; his ERA is second, at 2.46.
Cueto looks like the ultimate outlier, and by definition should not be able to keep this up. And yet, he has confounded our best metrics consistently by at least a half run in each season going back to 2011. At what point do we have to accept that what looks to be an unsustainable outlier might just be reality?
Cueto posts fine strikeout numbers and has better-than-average control, though he had never posted a walk rate below five percent before this season. He gets decent groundball numbers, but has allowed at least 10 percent of his home runs to go over the fence in each of the last three seasons, so it's not like he possess an impressive ability to keep the ball in the yard.
No, what Cueto does, consistently, is turn balls in play into outs. This is supposed to be, as you'll remember, the part a pitcher has the least control over. And yet, his .237 BABIP since the start of 2013 represents the best mark in baseball by 20 points. For his career, Cueto's BABIP is just .273, well below the league-average, which typically comes in around .298.
Typically, when looking for regression candidates, a BABIP well above or below league average is one of the first things we look for. This is why Nick Martinez should be at the top of your "Sell-High" lists, and why you should be trying to steal Carlos Carrasco if his owner is frustrated by his slow start. With Cueto, however, we have enough of a track record to say pretty definitively, this isn't a fluke at this point, it's a skill.
So, how does Cueto do it? What is it about the balls in play he induces that makes them so likely to turn into outs? In 2014, 24.7 percent of groundballs, 15.4 percent of fly balls, and 65.7 percent of line drives went for hits; for Cueto, those rates are 21.7, 18.4 and 67.7 percent. So, ground balls against him turn into hits less often than the league as a whole, but fly balls more often. So, that explains some of it, especially when you consider that he has played in front of some very good defensive infields, as well as in a bandbox of a stadium.
However, there is another place he has an even bigger difference. Per Baseball-Reference.com, in 2014, balls that were pulled went for hits 37.7 percent of the time against the league as a whole; for Cueto, that number is 37.9 percent for his career. However, on balls hit the other way and especially up the middle, Cueto has really fared well, posting opponent averages .030 and .015 points lower than the average for 2014, respectively. With Zack Cozart, Brandon Phillips and Billy Hamilton handling things up the middle, the Reds very well may have the best up-the-middle defensive trio in baseball.
Cueto also has a deep arsenal of pitches to draw from, with five different offerings he throws at least 12 percent of the time. Cueto doesn't mix up his speeds much, with 77.4 percent of his pitches coming in between 85 and 95 miles per hour this season. With how much movement he develops within that band of velocity, however, it's not surprising he can keep hitters off balance so effectively. Hitters can identify a pitch based on velocity, only for it to dive in on their hands as a 93 MPH two-seamer or cut outside the strike zone as an 89 MPH cutter.
The numbers back this up too, as Cueto has been one of the best pitchers in the game at inducing weak contact. According to FanGraphs.com, Cueto ranks 22nd out of 224 starters in soft-hit percentage since entering the league. Balls won't tend to go for hits when off-balance batters aren't making strong contact.
One thing to be concerned about if you are a Cueto owner is the trade rumors swirling around him. That's because the Reds have been one of the best teams in the league at turning balls in play into outs, ranking seventh in 2015, third in 2014 and 12th in 2013 in Defensive Efficiency, per BaseballProspectus.com. This is one place the Reds' bandbox park actually works out in Cueto's favor, as their fielders have less ground to cover in Great American Ballpark than in all but five parks, according to BusinessInsider.com.
Still, Cueto looks to have beat the system, somehow. For all we know about pitching, some players defy explanation. Cueto is just the latest, but he isn't the only one, as Matt Cain consistently outperformed DIPS in his prime thanks to low averages on balls in play. Some players just have that ability, and at some point, the sample size gets big enough where we just have to accept the results.
Cueto doesn't have the profile of an ace we usually look for, but in this case, the destination might be more important than the journey. Thanks to an unusual combination of skills and circumstances, he continues to defy the odds.