The Puzzle of Phillies prospect Mark Appel

Acquired from the Houston Astros in the Ken Giles trade, Philadelphia Phillies right-hander Mark Appel is one of the more puzzling prospects around. He was sent down to minor league camp earlier this month and will open the season in Triple-A but will certainly be on the short list for a big league promotion when the Phillies need an arm later this year. In spring camp he's thrown four innings, giving up just one earned run but with four walks against three strikeouts.

What can we expect? Appel still ranks highly on many prospect lists, but his status as an elite arm is starting to slip. First, check out this article by Chris Mitchell at Fangraphs back in December. Mitchell breaks down Appel's statistical comps using the KATOH system and comes up with a list of disappointing failures (Clint Nagoette, Greg Gohr, Chuck Lofgren, Kyle Drabek for example), but also some guys who struggled at times but eventually broke through (Homer Bailey, Wade Davis, Jake Arrieta).

The list. . .includes examples of pitchers who had good stuff, but mediocre minor league performance, and still succeeded in the majors. Pitchers are fickle creatures, and it’s not at all uncommon for breakouts to occur with little notice.

Second, here's my take on Appel from the 2016 Baseball Prospect Book:

Mark Appel, RHP, Philadelphia Phillies
Bats: R Throws: R HT: 6-5 WT: 225 DOB: July 15, 1991

Mark Appel is an odd duck. Fastball: 92-96 MPH, sometimes up to 97-98. Plus slider. Plus change-up. Usually throws strikes. Workhorse build, easy heat with low-effort delivery. Bright kid. Hard worker. That should all add up to rotation anchor but somehow it doesn’t. He is Philadelphia’s problem now, coming over from Houston in the Ken Giles trade, and perhaps the change of scenery and some fresh coaching eyes will help him. Last year I compared him to Luke Hochevar, "an enormously talented and intelligent pitcher who for whatever reason could never make it work for more than a few weeks at a time." I still think that is an apt comparison and who knows, maybe Appel will eventually find himself as a reliever as Hochevar did. Heck they even have the same height/weight data. Grade B, which feels generous actually.

Third, we turn back to Fangraphs and Dan Farnsworth's detailed analysis of the Phillies farm system, posted just this morning. He ranks Appel as the sixth-best prospect in the system (I had him at number seven on my own Phillies list). Farnsworth writes:

Appel keeps putting up numbers that bely his raw stuff, and it’s my opinion that the baseball community has glossed over some functionality issues with Appel’s stuff and delivery that contribute to his lackluster results. At his best, he pounds the zone with mid-90s heat, a strong breaking ball and a changeup with a good velocity differential. The problem is a general lack of feel, consistency and true command that makes his fastball too straight and hittable, the shape and location of his slider too unreliable and his changeup too straight.

I think Farnworth is very correct about Appel's straight fastball. It tends to play down; I've seen him get hit quite hard despite throwing 95-96. Dan knows a lot more than I do about pitching mechanics and offers this detailed breakdown, perhaps explaining why the results don't match the stuff:

His shoulders and arm end up almost dragging his hips into turning, rather than starting the move with the much stronger muscles in his hips and his core. When you ask an arm to provide both the majority of the force needed to throw, and also the precise adjustments for feel at release, it’s nearly impossible to do both consistently.

That type of movement inefficiency is rather difficult to change for the better. It’s not a matter of mechanics, really, since many pitchers have unique movement patterns they use to great success. In a rotational sport like baseball, the ability to properly sequence movements is a fundamental athletic requirement for the exceptional performers in the sport. Some are able to make up for it in compensatory ways, but Appel hasn’t found that key so far.

And this:

It’s not so dire that I don’t think he’s a major league starter, but his ceiling grade is lower here than most are ready to admit.

I agree with that entirely.

Let's try a thought experiment. What if Appel had been a fifth round pick instead of the first-overall choice in 2013?

Instead of a disappointment, he'd be seen as a promising arm who still needed to make some adjustments but could be a fourth or fifth starter. There's nothing wrong with that.  The problem of course is that in our universe Appel did go first-overall and will always be considered disappointing if he doesn't turn into an ace.

Appel still has time to turn things around. There are some positive statistical parallels as Mitchell points out (Arrieta and Bailey in particular). Another of Mitchell's KATOH's comps, Wade Davis, found himself in relief, as did my comp of Hochevar.

Where do you stand? Does Appel need to be traded to the Royals and moved to the bullpen to find success? Will he make some major adjustments and emerge as another Arrieta? Or will he be a mediocre starter? What's your take on this puzzle?