According to Jon Morosi, the Mariners are one of three teams interested in signing Zach Kroenke to a MiLB contract. The 28 year old left-handed pitcher spent the year in the Arizona Diamondbacks AAA, pitching 6 times (if I am counting the Game Logs right) against the Mariners’ AAA club. Kroenke pitched both as a reliever and a starter and didn’t have a lot of success, with a 4.55 FIP (.36 worse than league average) and 5.21 SIERA (.94 worse than league average). He struck out just 11% of the batters he faced, while walking 6.7 % of them (which is a good walk percentage, but not a good K/BB thanks to the bad strikeout rate). There really isn’t a lot redeeming about Kroenke’s season (other than he threw strikes at an above league average rate), as his GB % wasn’t very good either. He gave up a lot of contact, and it wasn’t weak contact.
Kroenke has thrown 10.2 innings in the big leagues in his career (a little in 2010 and a little more in 2011), obviously not enough to glean anything statistically, but it does give us some Pitch F/X data to look at (and a few spring training outings gives us some more data as well). He seems to be a sinker heavy pitcher, throwing it over half of the time in Pitch F/X parks (Again, because of small sample size issues, I wouldn’t put too much emphasis on this, and that is why we aren’t looking at the breakdown by counts data). This obviously explains the lack of strikeouts (but not the lack of ground-balls). The sinker averages 91.15 MPH, while his “normal fastball” (sometimes Pitch F/X has problems dealing with the differences between 4-seamers, 2-seamers, and sinkers, which is evidenced by FanGraphs’ insistence that he throws mainly normal fastballs) averages 91.53 MPH. So he has slightly below average to average (especially once you factor in the fact that he is left-handed) velocity, and also throws a slider and changeup. You can get an idea as to how those pitches break, along with where he normally places them with this image:
So it seems you can the difference between the sinker and the fastball by the way he throws the fastball high, while throwing the sinker lower. The slider and change (with the slider looking slightly lower) go lower than the sinker usually). The slider is somewhat in the softer to average category, averaging 82.93 MPH (the average slider in the Majors in 2012 was 83.3 MPH, but his sinker is nearly a full MPH above average. Most pitchers have a bigger difference in velocity between their sinkers and their fastballs). Kroenke’s change is 81.54 MPH on average, working as his softest pitch.
It is a starter’s repertoire of pitches, as he is not reduced simply to sinker/slider. However, if moved to the bullpen more permanently, I would imagine he would dump the change. I think he is stuck in the bullpen, most likely for a combination of reasons, but specifically for one I found interesting. When looking at his pitch mix, there is one thing really missing (or this is at least what I thought). A slow pitch or even a curveball (Brooks Baseball says he has thrown exactly one curveball, I am sure that is a classification error).
If you look at starters that throw anywhere between 90-92 MPH on their fastballs (on average, using FanGraphs data here), I count 94 out of the 107 pitchers in that category that throw either a curveball (9 were above 80 MPH on average though) or have a pitch that is lower than 80 MPH (on average). The 13 pitchers that didn’t fall into that category were Ross Ohlendorf, Jeanmar Gomez, Jason Berken, Nathan Adock, Bartolo Colon, Roberto Hernandez, Anthony Bass, Ervin Santana, Zach Britton, Tom Gorzelanny, Drew Smyly, Bud Norris, and Alex White. Those pitchers averaged an awful 122.93 FIP -, with only Colon and Smyly as above average pitchers. A 123 FIP – (rounding up) is exactly what Ricky Romero’s disastrous season came out to be. It is not a skill set that translates to starting very well (there aren’t a lot of good sinker/slider starters are there?).
So Kroenke should be brought in (if he is brought in), purely as a reliever. In 2011, he started 23 games in AAA, and wasn’t very good with a FIP .24 over league average and SIERA .51 over league average. His strikeout rate was a little better and his ground-ball rate was considerably better than in 2012, but it still wasn’t a very good year. If the Mariners have any thought of using Kroenke as a starter, it is just for AAA depth, as they may need a guy to eat up innings in Tacoma to replace some departing pitchers. Other than that, I would have to imagine that they think he could possibly help them in a relief role, even if he has to start in AAA. In his first year with the Diamondbacks organization (2010), he was used mainly as a reliever and was pretty effective, with a 3.68 FIP in the PCL. This makes his usage as a starter by the Diamondbacks even more puzzling, as they have some minor league pitching depth and the Reno Aces are consistently good (and won the championship for both the PCL and the AAA as a whole in 2012). In 2009, his last year with the Yankees organization (where he was drafted in the 5th round in 2005, one pick above Mitchell Boggs), he was effective as a reliever with a 3.64 FIP in the more pitcher friendly International League. The point is, I think he can pitch a little, as long as it is out of the bullpen.