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Joe Kelly's Evolving Mechanics

The complete lack of any kind of clever title for this particular piece is incredibly disheartening to me, but I just can't come up with anything at the moment. I'm sure the SEO people will be pleased, but I'm just depressed.

Steve Mitchell-USA TODAY Sports

If you've read much of my stuff here at VEB over the years, then you probably know that I am a bit of a pitching mechanics wonk. Not that I'm exceptionally knowledgeable about mechanics, mind you; only that I am hugely interested in the subject, and have read enough research that I can formulate a bunch of half-baked (often obnoxiously so), opinions relating to the same.

So, I was watching baseball over the weekend, as I am often wont to do. To be more specific, I was watching the Cardinals play Saturday night, against the increasingly-hated Pittsburgh Pirates. Francisco Liriano was on the mound for the Buccos, and taking the mound for the Redbirds was one Joe Kelly. That's the same Joe Kelly who beat out Carlos Martinez for the fifth and final spot in the Cardinal rotation this year, causing a fair amount of consternation amongst a certain segment of the fanbase, yours truly most definitely included.

Now, a couple things for background before I get into the meat of this post: my first objection to Kelly winning that rotation slot really wasn't about him, so much as it was about the player he was beating out. The thing is, I like Joe Kelly. I really do. But I think Carlos Martinez could be a top ten starter in all of baseball as soon as this season if given the chance. As much as I do, in fact, like Joe Kelly, there is absolutely no circumstance under which I think that same statement could be made of him.

My second concern about Kelly the starter is a little more nuanced. Kelly presents an interesting conundrum, in that I've always felt his profile fits best in a rotation, rather than as a reliever. He excels in rolling up high ground ball totals, but the strikeouts have never really been commensurate with the type of velocity, of raw stuff, that Kelly possesses. I actually prefer that sort of pitcher, a guy with a really solid batted-ball profile, as a starter. When it comes to relievers, I'm far less concerned with the kind of contact a pitcher generates, and more concerned there's just as little contact made as possible. I want my late-inning relievers in particular to strike out a whole giant load of hitters, with the rationale being that there are plenty of situations where a reliever is going to have to come into a game without enough margin for error to allow even a single well-hit ball in play, when a strikeout is basically the only result that really gets the job done. Starters, meanwhile, can have a bit more of a mixed-bag approach and still be very successful. Of course, the ideal would be for every pitcher on the roster to just strike out as many hitters as possible, but that's just not the way things work. As the leverage of a spot increases, the more I want to see a strikeout artist on the mound. In very sabr-y terms, I'm perfectly happy with a starter who looks really good by SIERA; when it comes to relievers, I just want the FIP to be good.

All of which is a very long-winded way of saying that I actually like Joe Kelly the pitcher better as a starter than a reliever, in terms of how he gets the job done. But -- and there's a fairly big 'but' here -- I also happen to have long been of the opinion that Joe Kelly has a horrible delivery, one that would very, very likely lead to injury at some point in the relatively near future. And what do we do with pitchers we believe are going to get hurt? That's right; we put them in the bullpen, because the lesser workload, both in terms of total innings and far less prolonged periods of work, should help to somewhat mitigate the extra stress they are incurring as they perform their duties. So I like Joe Kelly, groundball specialist, as a starter, but I hate Joe Kelly, mechanical problem child, as a starter.

One further thing: Saturday was the first time I had watched Joe Kelly pitch an entire game in 2014. I had caught bits and pieces of his spring training starts, but not a whole outing. Also, the always-strange camera angle of spring training is enough to keep me from really ever trying to determine much of anything about a pitcher in that setting. Horizontal variation in a camera angle I can deal with; mess with the vertical, though, and I just can't tell much about what's happening. So Saturday in Pittsburgh was the first I've seen of Joe Kelly in 2014 from a camera angle I had any confidence in as far as trusting what I was seeing.

Okay, that's out of the way. Now, here's why I'm actually writing this post:

I was watching Kelly pitch Saturday evening, and I kept thinking to myself, "You know, something about his delivery looks different. I don't know what, exactly. Maybe it's just my imagination."

The longer I sat there, though, the more I became convinced something was going on with Kelly that was different than in the past. So after the game, I went looking for proof. I, unfortunately, did not remember to DVR the game, so I had to go looking for said proof via the interwebs. So I cruised over to the Cardinals' website and pulled up a bunch of video highlights, and you know what? I'm pretty sure I was right.

For reference, the videos I was primarily looking at were this one, from last year's NLCS matchup with the Dodgers, and the highlight reel of Kelly's performance from Saturday night.

For further reference, just to see where Joe Kelly came from originally, I present you with a video from his time closing games in college at UC Riverside.

Now that, ladies and gentlemen, is a late arm. Watch where Kelly's arm is at the point his front foot plants; the ideal, I believe, is for a pitcher to be as close as possible to the high cocked position, in which the forearm of the pitching arm is vertical, at the moment he plants that foot. The further a pitcher deviates from that, the more it tends to increase the stress on his arm. There are plenty of other mechanical indicators when it comes to pitching, but most of it is window dressing; the vast majority of the stress a pitcher's arm will be subjected to in a delivery comes in the fractions of a second he's actually delivering the ball. Ergo, that's the most important part of the delivery, in terms of looking to reduce stress.

Remember, Kelly was never a pitcher before his sophomore year of college, if I remember correctly. He was a shortstop for most of his life (which shows in his remarkable athleticism, by the way), and only began pitching once he got to college. So when we're looking at Joe Kelly pitching in college, we're basically looking at a guy just sort of winging the ball up there as hard as he can, with very little idea of how to do so efficiently. I will say this: I do like how aggressive he is with his lower body in these early clips; there's a lot of power being generated by his very long stride. But timing wise, that's a really, really problematic delivery. His forearm, which again, should be somewhere close to vertical, is nearly parallel to the ground when his foot plants. His arm swing in general is just insanely long, in fact; and any delivery that long and complex is going to be almost impossible to manage.

Second clip, we move ahead to 2010, Kelly's first full season as a professional, when he was pitching for the Quad Cities River Bandits. The actual pitching starts around the 6:00 mark; it's a telecast from MLB Network, back when they put on minor league games instead of shitty talk shows featuring assholes who want to be Jim Rome when they grow up that really belong on some other network.

A quick aside: Kelly was pitching on this particular night against a very good Burlington Bees team, which is a Kansas City Royals affiliate. This was right around the time they had what was considered an historically great farm system; really odd part of the telecast: "Catcher, Will Myers."

Anyhow, the delivery is a little different here, but not much. The arm swing is still incredibly long, somewhat reminiscent of a pitcher like Octavio Dotel, to my eye. Unfortunately, due to the video quality, I can't get much of a screenshot to show you, but I did the best I could.


As I said, it's hard to see much of anything, but it's still relatively easy to tell his forearm is still in that near-horizontal position, similar to what he was doing in college. Again, that's incredibly late.

Now, I will say this: there are a couple positives about Kelly's arm action, even here. He has never been a guy who lifts the ball with his elbow, getting into that upside-down L position, or who brings his elbows up above shoulder level into the dreaded Inverted W. He's never had any of those pretty serious flaws; he was just a guy who had this crazy long arm swing that put his arm well behind where it should have been in relation to his body. (If you want to see what some of those other flaws look like, go watch Chris Carpenter throw. Or Mark Prior. Or, scarily, Shelby Miller.)

So, as of his first season in professional baseball, Joe Kelly's delivery was a real problem, I believe. Now, let's fast-forward to late 2013, when he was pitching against the Los Angeles Dodgers. Even last year, I didn't like Kelly's delivery much at all. It was no longer nearly so long as in his earlier days, but there were still some things I found problematic. His elbow was a bit high, for one. For another, at the back of his arm action he would show the ball to center field, a mechanical cue you'll occasionally hear about and usually results in the pitcher coming into the delivery part of his delivery with his thumb pointing down at the ground (pronated), which, again, tends to lead to his arm coming through late.

The nice thing here is the video quality from the Cardinal website is much better, so screenshots with a good amount of fidelity are possible. Two of them, in fact; the first is as close as I could get to the moment his plant foot comes down:


Notice that, thanks to the much more compact arm swing of Joe Kelly circa 2013, his arm is much closer to a cocked position here than it was back in 2010. In the Quad Cities clip, his forearm was still extended almost straight out, as he had yet to really even begin cocking it. That's the good part of this. The bad is that his arm is still quite a bit closer to parallel than perpendicular to the ground. So, still pretty late.

A second shot, from just a split second later:


His hips have opened, his shoulders have started to rotate, but his forearm is still shy of vertical. It's not terrible, the way it was in college, but it's still not very good. At this point, I would still say Joe Kelly's mechanics are very risky, and he's a reliever for me long-term.

And now, the metaphorical money shot. Or shots, as the case may be. I grabbed these screenshots from the Saturday night game at Pittsburgh; the angle is a little different, but not so much that I don't think they're extremely useful. I did the best I possibly could to get shots as close in time to what we have in the NLCS; it took me dozens of tries to get the video paused at the right moments. It's probably not perfect, but it's as close as I could get:


And, the second comparison shot:


Hips opening, torso rotating, and the vertical. I might still like his arm to get there a fraction of a second earlier, but we're talking milliseconds here. What we have here, in this latest iteration of Joe Kelly's delivery, is, in my ever so humble opinion, very good timing.

I also like the rest of his arm action now; his lifts his arm with the ball, rather than the other way around, his arm swing is relatively simple and compact, and watching him throw, I believe he may actually be able to repeat these mechanics, which should hopefully lead to improved command. Hopefully. He does seem a bit more passive with his lower half now, which isn't exactly a plus in my book, but if that's what it takes to get his timing to a better place, I'll take it.

What's kind of remarkable about this whole thing is Kelly appears to have drastically improved his delivery without sacrificing any velocity. Back in college, he topped out at 99 in short stints; in the outing Saturday, Kelly hit 98 mph at least once or twice I counted, and he was still comfortably pitching into the mid-90s as he approached the end of his night. Lower risk mechanics aren't always compatible with maximizing a pitcher's stuff; in Kelly's case, it appears he may have been so inefficient before that he hasn't lost anything in moving toward less-stressful ways.

So what does this all mean? Well, it means that, as we stand here today, on the morning of the eighth of April, I now believe that Joe Kelly may actually have a pretty good, pretty low risk delivery. Is it perfect? No, but there aren't too many deliveries out there I would call perfect. Does it mean he won't get hurt? Of course not; throwing a baseball is a brutally stressful activity, as there simply aren't many actions one can take which place so much stress on one particular body part. But I do believe Kelly has a much, much better chance of staying healthy now than I ever did before. And, from a mechanical standpoint, I think he's a pretty good fit as a starting pitcher.

Now, I would like to note that nowhere in this post did I necessarily say I think this means Joe Kelly is now a better pitcher than I thought he was before. The quality of a pitcher's output is often completely unrelated to how sound his mechanics are. Call it the Mark Prior Paradox; a pitcher with terrible mechanics can still be incredibly brilliant, right up until the moment when he just breaks. I hope that Kelly will be able to continue improving his ability to repeat his delivery and command his pitches, but there's really no guarantee that will be the case. And, just as importantly, I still happen to think Carlos Martinez is a better pitcher, no matter how you want to look at their respective roles or anything else. And so, I'm not really any less torn on things than I was before; I now think Joe Kelly is a better fit for the starting rotation than I did just a week ago, but I also still think there is a pitcher in the bullpen who would give the Redbirds a better chance at winning every fifth day out.

Still, I thought it was fascinating to look at how one guy has evolved over time in terms of how he goes about delivering a baseball. Joe Kelly is a phenomenal athlete, another trait I think should work in his favour, both in terms of health and quality of results (repeatability is a big function of athleticism, I believe), and it's clear to see that in less than five years, he's gone from raw thrower, relying on pure arm strength to just sling a fastball as quickly as possible to the plate, to something resembling a mechanically sound pitcher. Again, remember this is a guy whose entire pitching career is, at this point, roughly the last six years of his life. Maybe seven. That's really quite extraordinary.