Who is Jacob Turner? The Marlins, who just picked him up as part of the Anibal Sanchez/Omar Infante deal with the Tigers, hope he's the top-25 prospect lauded as a future power pitcher at the top of the rotation. But is he that guy? Turner has punched out less than seven batters per nine frames at Triple-A (6.8 K/9) and just 5.4 per nine in 25 big league innings spread across the 2011-12 seasons.
ESPN's Keith Law thinks Turner is having an identity crisis with his fastball, perhaps sacrificing stuff for the sake of ground balls and control (subscription required):
Turner was consistently up to 97 mph with his fastball in high school, touching 99, but is more 90-94 now. He works with a two-seamer that has some tailing life and generates a few more ground balls than his four-seamer does, but not enough to overcome the fact that he doesn't miss bats like he should...As much as I understand the idea of making starting pitchers more efficient, I don't get the idea of taking a power pitcher like Turner and turning him into a finesse/ground ball guy; I think he's lost a little arm speed, but that could also be a function of trying to 'pitch' too much instead of just letting it go.
Turner's fastball velocity has ranged from 88 MPH to 95 MPH in the majors, averaging 91.6 MPH overall. He's certainly putting the pitch over the plate (53.2 percent of his fastballs have been thrown in the zone, compared to the 51.9 percent average for starting pitchers) and keeping the ball low in the zone (45.7 percent of his fastballs have been thrown low, versus the 29.9 percent average). But so far, Turner's fastball is producing neither whiffs nor an exceptional amount of worm-burners. It's just getting crushed.
Here's Turner's fastball contact rate by pitch location in 2011-12, and then the league average:
League fastball contact rate by pitch location
Hitters have missed Turner's fastball just 10.7 percent of the time they've swung at it, far below the 14.5 percent MLB average for starters. That wouldn't be so bad if Turner generated lots of grounders with his fastball. But he has been more good than great in that regard:
Turner's ground ball rate with his fastball by pitch location
League average GB rate by pitch location on fastballs
Turner has generated grounders 48 percent of the time with his fastball. That's good -- the MLB average for starters is about 43 percent -- but not exactly elite. With few swings and misses and moderate ground ball proclivities, Turner's fastball is getting pounded. Take a look at his slugging percentage by location with the fastball:
League average slugging percentage by pitch location on fastballs
Opponents are slugging .619 against Turner's fastball to this point, sixth-highest among starters who have thrown at least 250 fastballs since the beginning of 2011:
|MLB Avg. for SP||.435|
None of this is to say that Turner can't become a quality, perhaps even elite, big league starter. He's just 21 years old, has thrown just 80 frames at the Triple-A level and has what amounts to a month's worth of MLB innings to his name. It's understandable that he still needs some polish. But he needs an identity. Is the whiff-inducing power pitcher who crept up on triple digits in high school? Or is he a ground ball juggernaut? Currently, he's just batting practice.