With the Miami Marlins' starting pitching staff struggling to find successful answers to their current holes in the rotation, the cries to get top pitching prospect Jacob Turner are getting louder from the Marlins faithful. When your team acquires a pitching prospect with the sort of pedigree that Turner has, it is not surprising. Turner came into the 2012 season as the 22nd ranked prospect in all of baseball according to Baseball America, and he was close enough to the majors in 2011 that he actually received three starts at the level last season.
But so far, Turner's work in the upper levels of the minors and in the majors has been underwhelming to say the least. Sure, Turner has a 2.99 ERA In two seasons at two different Triple-A affiliates, but his peripherals look a lot worse than those numbers suggest.
The real concern comes from the work of 2012, during which Turner has only struck out 15.0 percent of batters while walking 9.6 percent of hitters. Even at his age, that is not a good sign. Strikeout and walk rates are the first numbers you look at it in the minors just because that data shows whether a pitcher has the stuff and control to make it in the majors. Thus far, Turner's limited showings in the upper levels have not merited his prospect status.
But can even strikeout or walk numbers be deceptive? While a good amount of the blame is on Turner struggling to get strikes, some of it has been an inability to get the strikes at the right time.Swinging Strikes
Even though we consider strikeouts a "peripheral" stat that better shows a player's true talent, strikeouts in and of themselves are made up of even more parts. One of those parts happens to be something that is likely a "stable" statistic that varies more with skill and less with luck, and that is swinging strike rate or whiff / contact rate (if you look at the stat on a per-swing basis). Swinging strikes are likely very closely correlated with strikeouts. In 2011, among pitchers with at least 30 innings pitched, the coefficient of determination for strikeout rate and swinging strike rate was 0.65, meaning 65 percent of the change in strikeout rate can be explained by swinging strike rate in a linear regression. For contact rate, it is 67 percent.
So while it is not an entire determinant, swinging strikes are certainly a large determinant of strikeout rate. So what can this say of Jacob Turner's strikeout rate potential? In the 2012 season, his swinging strike rate in the minors has been at 8.7 percent in between his time in the Tigers and Marlins organizations. The 8.7 percent rate would rank fairly middle-of-the-pack in the majors; in fact, such a mark would have been tied for 47th among qualified major league starters.
What type of starters had swinging strike rates around the mark Turner put up? Here are the ten men who had the closest swinging strike rates from the list.
Only one of these pitchers, Trevor Cahill, posted a strikeout rate below average using these swinging strike rates. Again, while swinging strike rate does not correlate one to one with strikeouts, the r-value for swinging strike rate is at 0.81, which is still fairly high. If Turner can simply maintain that swinging strike rate in the majors, he has a very good chance of at least hitting the league average strikeout rate between 18.5 and 19.5 percent (19.6 percent so far in 2012).
We can use a similar approach using contact rate. Both in the minors and in his brief major league stint in 2012, batters made contact with just about 80 percent of Turner's pitches at which they swung. Here are the ten pitchers with the closest contact rates in 2012 among qualified starters.
Only two players were shared among the two lists, yet the strikeout rates of the two lists were identical. Then again, this should come as no surprise, as contact rates and swinging strike rates likely correlate extremely well, almost at a one-to-one level. But the point here is that, with the kind of stuff that Turner has displayed even in a down year this season in Triple-A and in his poor showings in the majors, he is likely to be capable of striking out more batters than he has thus far. That is a positive sign for Marlins fans.
Scouting His Stuff
It is also easier to believe that Turner can turn around those strikeout concerns based on his impressive repertoire of stuff. The descriptions of his stuff prior to this season were all fantastic, claiming a low- to mid-90's four-seam fastball and a low-90's two-seamer with heavy sink, one of the best curveballs in the minors, and a solid third pitch in his changeup. Scouts vary as to the excellence of these pitches, ranging from average to plus, though they all agree that the curveball is a plus offering.
With that kind of consensus on his stuff, it is hard to see Turner not turning around the strikeouts. It is well known that he has gotten by more with control than overwhelming stuff thus far in his minor league career, so it is likely that he will not start his career with rates even similar to the 21 percent strikeout rate listed above from his comparables. Still, there should be a good chance that Turner ups the rate close to 17 or 18 percent once he reaches the majors full-time. With some regression in the absurd home run rates, all that will be left is to see if he can use the command and control from previous season and drop that walk rate.
Marlins fans, Jacob Turner should be just fine.