Swinging-strike rate: 11.8 percent
Sean Manaea wraps up the first page of results, ranking at the 30th-best whiff inducer on Fangraphs, just behind former teammate Sonny Gray and Hyun-jin Ryu. With Manaea, we’re working with a guy who has above-average stuff yet still has fanned just 7.9 batters per nine. He’s right around the league averages in walk, strikeout and groundball rates, but Manaea seems to just have much, much more left in the tank.
His second half in 2016 tells the story of what he’s capable of, as he posted a 2.67 ERA, 8.0 K/9 and a WHIP of just 1.02 while toiling in relative anonymity for another forgettable Oakland Athletics club. What we see from Manaea that has us intrigued was that he’s getting a healthy 7.6 percent whiff rate on his four-seam fastball, and each of his secondary pitches are in the 20 percent vicinity. For some reason that isn’t entirely clear, he’s backed off his offspeed and breaking stuff a bit this year in favor of the fastball, and the reason why could be as simple as the slight uptick in his walk rate.
If Manaea working from behind hitters, that would mean more fastballs, and as a result, worse numbers overall due to count leverage. Nevertheless, the repertoire here from the lefty is electric, and he should only provide improved results the more familiar he gets with the league. He could be a breakout arm in 2018.