Is Julio Teheran Truly the Atlanta Braves' Ace?

The Atlanta Braves have taken control of the NL East, and, once again, they've done so on the strength of their pitching. Both their starters and relievers have put up numbers that put them in the top half of the league, and that’s with losing two of their top pitchers – Kris Medlen and Brandon Beachy – before the season even started.

The pitcher who has risen to the cream of the crop has been Julio Teheran. He has a sparkling 1.77 ERA – the third-best number in the league – in a team-leading 76.1 innings pitched. But has he really been the Braves ace so far this season?

Some Troubling Numbers

For as great as Teheran's numbers look, the advanced metrics don't support them. His fielding independent pitching (FIP) is 3.64, and his SIERA is 3.75, numbers that would actually have him ranked near the bottom of the rotation.

So why is that?

Last season, he ranked 16th in the league with a 3.78 K/BB, but has seen his strikeout numbers drop while his walks are up. And it's certainly easy to poke holes in his incredible .191 batting average against, with a BABIP of .216 having a lot to do with it.

There's no denying the Braves have a great defense. The problem is no other pitcher on the staff has come close to putting up the same numbers.

It's possible that Teheran has been partly responsible for the number, just not enough to explain a .216 figure. Last season the best BABIP belonged toJose Fernandez at .240, and Teheran hasn't shown that same potential.

He had a BABIP at .288 last season, and has never had numbers much better over a full season at any level. And if that BABIP rises, you can expect his exceptional left on base percentage (LOB%) of 87.6% to drop, and his 1.77 ERA to rise.

The Competition

So if we can't trust Teheran's numbers, is there anyone else on the staff that has pitched like an ace?

Aaron Harang

He is the only other starter to log 11 starts so far this season, and the advanced figures seem to really love him. His FIP is the lowest on the team at 2.19, and only Alex Wood has a lower SIERA. He even has a 2.0 wins above replacement (WAR).

The biggest number that pops out for Harang is his 25.9 strikeout percentage (K%), easily the highest of his career. His average has been 19.1%, and the highest he’s ever put up before this was 23% in 2007 with the Cincinnati Reds.

Harang is getting swing and miss rates like he was earlier in his career. From 2005-2007, Harang was always over 10%, and this season he’s back above the mark at 10.2%. Remarkably, he’s done this by pounding the strike zone with his high-80s MPH fastball, a la Bartolo Colon – who did have the second-best ERA in the AL last season.

Harang’s 3.29 ERA isn’t near the top of the league, but he’s doing that with a BABIP of .331 and a 69.4 LOB% that’s below his career figure. Even more impressive, he’s managed to keep a BAA of just .244.

What scares you with Harang is a home run-to-fly ball (HR/FB) ratio at 2.9%. Unsustainable doesn’t begin to describe that figure - 6.3% is easily the lowest number he’s had over a full season, and his career figure is at 10.3%. There is just no way that number stays where it is.

It's also hard to imagine him continuing to get the strikeout numbers he's been putting up. After all, Colon managed to regress this season.

Ervin Santana

While his ERA of 4.06 is pretty pedestrian, even his advanced figures are better than Teheran’s.

Like Harang, Santana is putting up the best strikeout numbers of his career. He has a 22.9 K%, and has a swing and miss number at 12.2 percent. He’s even holding batters to a .259 average despite a BABIP of .319.

He’s also putting up the lowest home run numbers of his career, even with a HR/FB right around his career average at ten percent. But that’s about the last nice thing you can say about him.

In his five starts in May he has a 6.00 ERA and a 4.45 FIP. Worse, his line drive percentage (LD%) has skyrocketed this season. It’s up to 25.3 percent, even though he’s averaged less than 20 percent over his career.

Alex Wood

Wood is another pitcher that's seen an increase is his K%. In fact, he has the best K/BB in the rotation at 4.14. And his FIP and SIERA are two of the best figures on the team.

Overall he has a 3.40 ERA despite a BABIP at .353 and a HR/FB that's risen to 12 percent from 5.1. Even crazier, he has a LOB% of 81.1%, while giving up close to a home run over nine innings (HR/9) and sporting a relatively high BAA at .276.

But last season he had a high BABIP too. And while his HR/FB numbers have gone up, so has his fly-ball percentage (FB%). It's almost at 33%, after being close to 27% last season. He's also been moved to the bullpen recently. The Braves have a crowded rotation, and decided to move Woods to the pen to clear things up. That hardly screams ace.

No one else on the staff is really in the conversation.

Verdict

So back to Teheran.

It's important to note he didn't have a great FIP (3.69) or SIERA (3.55) last season either, and he still put up good numbers. And his low BABIP could be partly a product of better pitching. A low number usually comes from weak contact, and Teheran's 17.2 LD% – a drop from 21.2 percent – supports that. Even his K/BB hasn't dropped much from last season's stellar number, down to just 3.21 from the 3.78 number he put up last season.

But the most important number for Teheran is his innings.

You want the ace of your staff to be the work horse, and that's what Teheran has done so far. Teheran probably won't finish the season as one of the premiere pitchers in the league, but after all the injuries the Braves faced in the rotation, he is becoming its leader.