When Chicago Cubs starter Kyle Hendricks takes the mound Monday night in St. Louis, he’ll do so with an MLB-best 2.07 ERA. As manager Joe Maddon likes to say, that’s good stuff. But it’s only when you begin to burrow beneath that sparkling figure that the full scope of Hendricks’ breakout season begins to take shape.
Hendricks’ lead in ERA over second-place Noah Syndergaard (2.48) is now .406. That’s the largest gap between first and second place in MLB ERA since Jake Peavy’s .469 gap over Brandon Webb in 2007. And it keeps getting bigger: Since the beginning of July, Hendricks has a 1.22 ERA, which is .9 runs better than any other pitcher in baseball. Washington’s Max Scherzer clocks in a distant second at 2.12.
We should acknowledge that if Dodgers ace Clayton Kershaw had not been injured, we would not be harping on Hendricks’ ERA gap. Kershaw has a 1.89 ERA, but is almost certainly not going to qualify for the ERA title.
That aside, if Hendricks retains his current ERA advantage, at season’s end the gap would be the 30th-largest gap in 146 years of big-league ERA champs. During the 60 years that Cy Young awards have been handed out, it would rank 13th. Either way, it’s about a once-in-five-years performance.
Unfortunately, having a huge ERA gap doesn’t guarantee Cy Young hardware. Of the 12 Cy Young-era hurlers who have won the ERA title by a bigger margin than the one currently enjoyed by Hendricks, eight won the award:
Bob Gibson, 1968
Ron Guidry, 1978
Greg Maddux, 1994 and 1995
Pedro Martinez, 1999 and 2000
Randy Johnson, 2001
Jake Peavy, 2007
And four did not:
Whitey Ford, 1958
Hoyt Wilhelm, 1959
Kevin Brown, 1996
Roger Clemens, 2005
HOW HE HAS DONE IT?
Hendricks is in the middle of an amazing Cy Young chase despite a much-discussed absence of power pitching. His average fastball speed (87.9 MPH) ranks 78th out of 82 qualifiers, and two of those behind him are knuckleballers.
Yet it’s not fair to say that Hendricks’ fastball is ineffective. His .735 OPS allowed on fastballs ranks 22nd in baseball and is 65 points better than the big-league average. The biggest reason for this is movement: Hendricks’ average break length on fastballs (6.3 inches) ranks fifth among qualifiers. Second, there is command: Hendricks gets his fastball into the lower half of the strike zone about 13 percent more than the league average.
Hendricks actually has a max velocity of around 91 to 92 MPH, but has learned that movement and location are more important for him than velocity. During his postgame chats with the media, one of his first self-critiques of any outing is about his fastball command, and never is the word “stuff” uttered. In fact, Hendricks has rarely overthrown his fastball this season. But last season, he allowed a .935 OPS on pitches of 90 MPH or more. He threw 111 such pitches. This season, he’s thrown just 34.
So while Hendricks has a “slow” fastball, the pitch is really quite effective. And any fixation with that pitch ignores the fact that the most important thing about Hendricks’ fastball is that it sets up his changeup, which has become one of the best weapons of any pitcher around. Only three pitchers have thrown more changeups than Hendricks. And his success on that pitch has yielded a haughty strikeout rate (29.1 percent) and a .338 OPS allowed that ranks 14th out of 203 pitchers who have thrown at least 100 changeups.
BUT CAN HE KEEP DOING IT?
What we really want to know about Hendricks' run is how likely it is to continue. The question of sustainability not only is crucial to what we can expect of Hendricks’ postseason prospects, but perhaps also to his Cy Young candidacy. On that latter front, you figure the more his performance is sustainable, the more it’s a product of things under his control and less subject to variance. In theory, that bolsters Hendricks’ award viability, because then you can’t as easily dismiss his numbers as mirrors and great defense.
Though Hendricks doesn’t have a power-pitcher makeup, the effectiveness of his pitches has resulted in unremarkable peripheral stats. His strikeout rate is just a tick below the big-league average. His walk rate is better than that, but not anything like Kershaw. His homer rate is better than average but not extreme. And while he’s more of a ground ball guy than a fly ball guy, on the whole, his ball-in-play hit types are fairly balanced. There is nothing here screaming regression to the mean, either in a good way or a bad.
That brings us to what may be the key metric behind Hendricks’ success. This statistic is called “well-hit average,” a metric in the ESPN database compiled by Inside Edge. It rates every ball hit into play according to how well it was struck, and that information is aggregated for both hitters and pitchers. Among qualifying hurlers, Hendricks leads the majors in WHA at .096.
Here’s what we want to know: To what extent is WHA sustainable? It’s a cool metric, but if it’s not something that holds up from season to season, it’s merely descriptive.
To test that, we looked at all two-year stretches (since 2009) in which the same pitcher threw a minimum of 100 innings in both seasons, and ended up with 694 matches. Then we measured the year-to-year correlation in four areas: strikeouts per 9 innings, walks per 9 innings, homers allowed per 9 innings and well-hit average. Perfect correlation is 1.00, and the closer you get to that figure, the stronger the year-to-year correlation, or sustainability, of the metric. The chart at right shows how our categories ranked.
Good news! (Well, if you’re rooting for Hendricks.) Esoteric as it sounds, well-hit average is a metric that seems to have a high level of year-to-year correlation. In this sample, it’s not as strong as strikeouts, but a little more sustainable than walk rate and way more than homers. This suggests, rather strongly, that the key metric explaining Kyle Hendricks’ success is sustainable, a product of his efforts and not luck, or other unseen forces.
Nothing is guaranteed of course, especially in the playoffs, where randomness probably trumps everything. But if you want to nitpick Hendricks' lofty ERA, good luck. It’s for real. Simply put, the guy is hard to hit.