The Atlanta Braves have locked up another franchise cornerstone, signing Julio Teheran to a six-year, $32.4 million deal that includes a $12 million option for the 2020 season. The 23-year-old righty was arguably the best of the Braves' home-grown rotation as a rookie. Teheran compiled the best strikeout-to-walk ratio (3.78) among qualified rookie starters and posted a park-and-league-adjusted ERA that was 21 percent above average, trailing just Miami's Jose Fernandez.
While Teheran has already established himself as one of the better young arms in the game, he could enter elite territory by limiting hard contact against left-handed hiters. He's not Charlie Morton Jr. or anything, but Teheran showed a sizable platoon split in 2013. He shut down righties, striking out 26 percent of batters faced and limiting them to a .317 slugging percentage. Against lefties, however, Teheran whiffed only 17 percent of hitters and allowed a .483 slugging percentage. To become platoon-proof, Teheran must miss bats with his fastball and better locate his breaking stuff.
Teheran isn't really a power pitcher, with an average fastball velocity (91.4 MPH) slightly below the big league average for right-handers (91.7 MPH). Don't tell that to righty hitters, though -- they swung and missed 24.4 percent of the time against Teheran's modest heat, the highest clip for an NL starter in righty-vs.-righty confrontations and fourth in the majors, behind Yu Darvish (28.4%), Hisashi Iwakuma (26.4%) and Anibal Sanchez (25.6%). Lefty hitters, by contrast, didn't have near as much trouble connecting against Teheran's fastball.
Righties' contact rate by pitch location vs. Teheran's fastball, 2013
Lefties' contact rate by pitch location vs. Teheran's fastball, 2013
Lefties swung through Teheran's fastball 13.3% of the time, below the 15.5% MLB average for righty starters against opposite-handed hitters and barely above the likes of punchout-challenged arms like Jeremy Guthrie and Kevin Correia. Righty hitters barely made a peep against Teheran's fastball (.339 slugging percentage), but lefties routinely reached the gaps (.490 slugging percentage).
Teheran's low-80s slider and slurvy, low-70s' curveball were also much more effective versus same-handed batters than lefties. Though he generated an equal number of whiffs with his breaking pitches (hitters on both sides of the plate swung and missed a third of the time), Teheran stifled righties (.315 slugging percentage) and got lit up by left-handers (.490).
Why the big difference? Command. Teheran threw 23.7% of his sliders and curves to the horizontal middle of the plate versus righties (under the 24.2% average), but 27.7% against lefties. Pitchers get pummeled when they leave breaking pitches over the middle of the plate -- hitters slugged a collective .451 last season -- and that's especially they case with Teheran. When he left a breaker over the middle, left-handers took him deep five times and slugged .765.
Teheran is remarkably polished for such a young pitcher, and he's already an asset despite a big platoon split. If Teheran starts deceiving lefties with his heat and spotting his breaking stuff, GM Frank Wren will look like a genius for buying out his potentially pricey arbitration years and a season or two of free agency.