For those who subscribe to the notion of "aces" in baseball, when looking at Julio Teherán's stats on the surface this season, it'd be hard not to immediately describe him as a member of that club.
The 23-year-old Colombian righty, through eighteen starts and 126 innings this season, has posted a stellar 2.29 ERA, good for fifth in baseball, and a 108:26 K:BB ratio. Needless to say, a better than four-to-one ratio of strikeouts to walks and an ERA that would be good enough to lead the league in many seasons would suggest that the Braves' Opening Day starter has quickly and fairly easily ascended from being a standout prospect to a legitimate "ace" on a playoff-contending team in the Major Leagues.
Teherán's 2014 success comes on the heels of a successful rookie campaign in which he rebounded from a poor performance as a member of the AAA Gwinnett Braves in 2012, posting a 3.20 ERA with a 3.69 FIP (3.76 xFIP) and finishing fifth in Rookie of the Year balloting. His 2014 success isn't completely unexpected, as many suggested that Teherán would build on the success of his first year in the bigs and become a front-line starter for Atlanta sooner rather than later. His efforts, and to some extent, his potential, were rewarded in February with a six-year contract extension (with an option for a seventh year) worth $32.4 million, a deal that looks to be a steal for Atlanta going forward, with the obvious possible injury caveats.
We all remember the consternation and grumbling about the Braves' purported lack of an "ace" that occurred last season, especially as the playoffs neared. Many fans, and even writers and analysts, believe that it's necessary for playoff teams to be able to trot out an "ace" in a do-or-die game, as if doing so ensures victory. Although this type of thinking is flawed and fallacious (hello, World Champion 2013 Boston Red Sox!), it would be silly to argue that having an "ace" isn't a valuable commodity for any team. Teams with bonafide frontline starters such as the Dodgers with Clayton Kershaw and the Mariners with Felix Hernandez may not be guaranteed a win every fifth day, but it's certainly advantageous to be able to rely on a starter who consistently stymies opposing offenses.
So, this brings me back to Julio Teherán and the outstanding results that he's achieved so far in 2014. Teherán has been selected to participate in the All-Star Game in Minneapolis next week, and deservedly so. ESPN's Christina Kahrl wrote a nice piece detailing Teherán's success this season and certainly doesn't shy away from throwing the "ace" designation on Teherán. He has been a workhorse and an anchor of the starting rotation on one of the Majors' best pitching staffs, and has excellent traditional stats despite peripherals suggesting that he may be the beneficiary of some fortune thus far this season. Just how much luck has Teherán received, though, and can we expect him to achieve "ace-like" results going forward?
One of the primary criticisms of defense-independent pitching statistics such as FIP, xFIP, and SIERA is that pitchers have an ability to influence their BABIP allowed. One of the classic cases of this is the career of former Brave Tom Glavine. Despite a career FIP of 3.95 that would suggest a merely good, as opposed to Hall of Fame-worthy, pitcher, he consistently outperformed his peripherals and finished with a career ERA of 3.54. In other words, Glavine was able to win over 300 games and go down in the annals of baseball as one of the best pitchers of his era despite a decidedly non-sexy number of strikeouts and a walk rate that was merely above-average. Glavine induced "weak" contact to the tune of a career .280 BABIP against and a low number of home runs allowed, allowing his concrete results to outpace those expected by DIPS-oriented statistics.
It's certainly possible for pitchers to control at least part of their BABIP allowed, as pitchers who induce ground balls and lazily-hit fly balls (many pitchers with good IFFB% numbers will have some of the lowest BABIPs allowed in any given year) and limit line drives and hard contact generally have stronger BABIP numbers than those who don't. Additionally, research such as this 2005 piece by JC Bradbury which touches on the matter has shown that pitchers with the ability to strike out a high percentage of hitters generally allow lower BABIPs. This is somewhat intuitive, as pitchers who have the ability to miss bats should also have, in theory, the ability to prevent hitters from squaring balls up and generating solid contact.
To this point, Julio Teherán has allowed a .269 BABIP in his 337.2 career Major League innings, a number that is considerably lower than the generally agreed-upon league average that hovers somewhere around .300. Teherán's batted ball profile probably isn't what you'd expect for a pitcher who has allowed such a low percentage of batted balls against him to fall as hits, as he is a decidedly fly-ball oriented pitcher whose career ground ball percentage is a mere 36.8%. His numbers aren't much different in 2014, as his current batted ball splits currently look like this:
Here's a batted ball map to visualize the balls put into play against Teherán this season, courtesy of Fangraphs.
So, we can see that Teherán induces tons of fly balls. Luckily for Julio, Atlanta's outfield defense, headlined by all-world defender Jason Heyward, is one of the strongest in the Major Leagues by almost all accounts. Braves outfielders rank second in baseball with a UZR/150 of 12.1, sixth with 17 defensive runs saved and second with 25.2 range runs, which basically demonstrates that the Braves have an outfield that saves a bunch of runs by displaying excellent range as a whole. This plays into Teherán's strengths as a pitcher, allowing a high ratio of fly balls to be converted to outs by the Upton brothers and Jason Heyward.
While excellent defense behind him has been a large component of his successful season, his .242 BABIP against to this point in 2014 simply isn't sustainable, no matter how proficient a defense is at converting balls in play into outs. ZiPS projects Teherán to allow a .306 BABIP through the rest of the season (Steamer is a bit more optimistic regarding his ability to control his own BABIP fate, projecting .282), and I think this is likely a bit high considering his relatively low career baseline and the batted ball profile that allows the Braves' defense to play to his strengths.
Another red flag on Teherán's statistical profile that is something that will likely work in conjuction with some deflated batted ball luck is his abnormally low HR/FB%, which sounds complicated but isn't. Simply put, Teherán is allowing a lower-than-expected ratio of home runs to fly balls allowed; thus far, only 7.2% of fly balls given up by Teherán have gone over the fence. It goes without saying that HR/FB% luck is a big deal for fly balls pitchers such as Teherán. Last year, the ratio of homers to fly balls given up by him was much closer to the league average (10.1%), which tends to fluctuate around 9.5-10%. Even by taking a look at the embedded hit chart above, it's possible to see that Teherán has given up quite a few long fly balls that haven't left the yard. He's been fortunate in this regard so far in 2014, but it'd be surprising to see his fortunate run continue.
So, with those two potential areas for regression mentioned, what should we expect from Teherán going forward? Will he continue to produce numbers worthy of front-line starter status, or is he due for serious and painful changes in his results?
|2013 Julio Teherán||22.0%||5.8%||10.1%||80.9%||.288||78.5%||10.5%||3.55||3.20|
|2014 Julio Teherán||22.0%||5.3%||7.2%||79.9%||.242||77.1%||11.4%||3.51||2.29|
If you throw out the BABIP and the HR/FB numbers (as well as the ERA, obviously), it's almost stunning how similarly Teherán has pitched in 2014 as he did in 2013. He is striking out the same percentage of batters, is walking only marginally fewer hitters, and is stranding roughly the same percentage of baserunners as he did last season. He has seen marginal improvements in opponents' hitters' contact percentages and swinging strike percentages (I would propose that his increased confidence and usage of his changeup this season has something to do with this), which could indicate that he may see a slight bump up in his strikeout rate as the season continues. However, my favorite DIPS indicator, SIERA (on which a primer is available here), indicates that Julio is just continuing to be nearly the same pitcher that he was last season.
Our former colleague Mark Smith wrote an analytical piece on the evolution and metamorphosis on the evolution of Teherán last August that does an excellent job detailing how Teherán altered his M.O. as a pitcher and found success last season. Which brings me to the final sentence of his piece...
...it's been a joy to watch Teheran begin to blossom as a major-league starter. We just have to remember that he's not an ace ... yet.
So, has Teherán taken that step towards becoming an "ace" yet?
As a disclaimer, the definition of "ace" varies depending on who you ask and is arbitrary. However, considering Teherán's likely home run rate and BABIP regression, it seems that his true talent level and what we can expect from him going forward may not quite be at the level of "acedom."
Despite some subtle improvements in swinging strike percentage and contact percentage allowed, Teherán hasn't improved his strikeout percentage. This could change and it wouldn't surprise me to see a slight bump up for Teherán in his strikeout rate, but I wouldn't expect any dramatic improvements. This isn't necessarily a bad thing though, as he still strikes out an above-average number of hitters. This, in combination with a walk rate that's borderline excellent, provides a solid base for Teherán as a pitcher. Nonetheless, he still isn't an elite strikeout pitcher (this could change in the future, mind you) and is still going to be somewhat susceptible to the whims of batted-ball luck. Fortunately for Teherán, he's going to be aided going forward by excellent outfield defenders behind him, which will help him keep his ERA lower than what certain DIPS indicators would suggest.
ZiPS projects Teherán to achieve a 3.38 ERA (3.48 FIP) the rest of the way in 2014, and this seems like a fair estimation considering the elements of his game as a pitcher that I've spoken about beforehand. While a starter who puts up those numbers could safely be considered a solid number two starter, it may not quite be an ace-worthy figure that we've seen thus far from Teherán, and that some may expect from him going forward.
This isn't meant to be an article that proposes that Julio Teherán is a mirage and can't be expected to succeed at the front of the Braves' rotation going forward. Simply, I think it's just okay to acknowledge that he, at this stage in his career, may not be realistically expected to live up to the "ace" billing that some have bestowed upon him lately. He's been the beneficiary of a bit of luck on the BABIP and HR/FB fronts and of pitching in front of a defense that plays to his strengths perfectly, which makes him appear a bit better on the surface than he "truly" is at this point. It might be just a little too high of an expectation to pin the "ace" tag on him just now.
Nonetheless, Atlanta will be fortunate to have a pitcher of Teherán's caliber (especially considering his age) for this season and five more, at least. Pitchers tend to transform and adapt as they age, and it wouldn't be a stretch at all to think that Teherán could become a bonafide front-line starter and ace in the near future. He certainly has the tools, and perhaps we could see him continue to better utilize his changeup going forward in order to further his progress.
At any rate, Julio Teherán is a quality, front-end starting pitcher in the majors at 23 years of age, and almost certainly the best starting pitcher on his team. "Ace" or not, that's a highly valuable commodity and absolutely nothing to scoff at.