Thursday, July 11, 2013

Does Joba Chamberlain Still Have Value?

Recent reports have the Yankees trying to trade Joba Chamberlain, a one time top prospect that has had problems with both health and ineffectiveness. The Phillies were rumored to be interested, but have since reported that they are not interested. So far this season, Joba is still missing some bats (but has seen a drop), but is walking too many hitters and is having some home run problems. Not the kind of relief pitcher that is going to be extremely valuable.

I think it will be helpful to look at three different seasons for Joba. First, 2009, the only year he was used as a starter in exclusivity (he did have 1 relief appearance, but 31 starts). Then,.2010, when he first moved to the bullpen full time, and because of injuries, really the only year he has been in the bullpen for a full year. As a starter, he was okay, below average, but a quality back of the rotation piece. In 2010, he had a very mediocre year in the bullpen by ERA, but had a good year by defensive independent metrics. The third year in this post that I'll look at is so far in 2013, as we want to determine whether or not he still has present value, by comparing this year to the two previous years, where he did have value.

I'll also break it down by platoon splits, as for his career, Joba has been about equally effective against both lefties and righties, and he was in 2009 and 2010 as well. Obviously 2013 is too small of a sample size to look at splits, but breaking up the graphs by splits gives us a better idea of how he is actually pitching on the whole. First, let's look at how he has pitched lefties since 2008 (including the years we aren't looking at individually)

One thing you notice is that he doesn't change the slider location horizontally by platoon, which can be a problem. However, he does move it vertically, much more than the average pitcher based on platoon splits. He makes sure he throws it lower to lefties on average, as you can see by looking at how he is pitched right-handed batters for his career

As I mentioned before, Joba has not had big platoon splits in his career. The slider is no different, actually better against lefties on a whole (19.6 % swinging strikes against righties, 25.6 % swinging strikes against lefties). The vertical difference would seem to play a big reason for this. Here is how Joba attacked lefties in 2009, as a starter

Obviously the velocity is a tick down, which you would expect as a starter, but it isn't drastically down. He still had pretty good stuff as a starter. The locations are basically the same (the slider might be a little higher), but there is at least some kind of bias, as 2009 has the most pitches. He kept the ball extremely glove side other than the slider. Here are how Joba's results broke down against lefties in 2009

This graph shows how effective the slider was against lefties. His problems came when he threw up in the zone and slightly more glove side (inside to lefties). The velocity drop on the home runs is a little curious. Here are how his average result locations looked like against lefties in 2010:

As a reliever, he clearly threw harder on average, lower and more glove side as well. His home runs came when he went up and in, but the contact came low in the zone like the average pitches, but slower as well. The whiffs came more arm side than they were in 2009, and they were also harder. Joba seems to be the rare pitcher that is more likely to get swinging strikes the harder he throws. Joba has never been a heavy changeup user, but he has just thrown 2 so far in 2013. He threw just 1 to left-handed batters in 2010 (so basically, since he has moved to the bullpen he has ditched the pitch, which makes sense considering his slider is effective regardless of the platoon). Because in 2010 he actually located his slider out of the strike zone on average, this graph is the one where the entire graph is not the strike zone (as the strike zone itself shows) 

The fastball is located both high and low about equally in 2010, showing how he was pitching lower that season. The curve was kept either further away from lefties that season as well. Fast forward to how he is pitching lefties so far this year:

 He is locating even lower with all his pitches on average now, with some reduced overall stuff. However, his fastball has actually seen an uptick. This is why I thought Joba was so interesting. At times I have seen him pitch this year, his fastball still looks great, especially velocity wise. The curve and the slider have dropped in velocity, and he is throwing more glove side with the curve against lefties. As a whole, the curve has been his worst pitch so far this year (by wRC + according to FanGraphs). Here are what his results look like against lefties so far this season

The whiffs are still coming low in the zone and glove side, the general area of the slider. The one home run came on a good fastball, a little higher and arm side than his average pitch, the same location as his average contact given up. The average contact is actually coming on harder pitches, showing that for some reason, his fastball is less effective. I think it does have something to do with the fact that he is throwing it lower on average, even if the contact is higher than the average pitch thrown. His fastball, one of a four seam variety (with an occasional FT tag, that I converted into FF for ease), is meant to be thrown high in the zone. This is what he did when he was a starter, but he isn't doing it anymore. How about against righties? The following three graphs in a row is how he has pitched by average locations and velocity in the three selected years:

Obviously the easiest part of the distinguish the difference is the lack of changeup in 2013, which is probably the least consequential, as he never threw it much anyway. The curve also provides a big difference, as he is throwing it harder (though he is throwing the slider softer, suggesting some tag confusion) and throwing it to the complete glove side, further away than he ever has before. Horizontal curve location, as long as it isn't inside to hitters, doesn't appear to matter much, but whiffs on curves usually come away from hitters, so it would appear, even though the pitch has been awful this year, that he is locating it in a good spot. While he is throwing the fastball more glove side than ever, he is also throwing it higher and harder. He is keeping it up, away, and throwing with premium velocity (the velocity increase from lefties to righties suggest that there probably should be FT tags for Joba, he probably is throwing a moving fastball). It should be more effective than it is.

Joba is getting the whiffs in slider and curveball locations and they are on pitches that he is taking velocity off of on average. The home runs are coming when he isn't getting the ball glove side, and his contact allowed is coming on pitches that are a little higher and more glove side than his average pitch. Compared to 2009-2010, his whiffs are coming on much lower pitches on average this year, but his home runs allowed are lower, and his contact is about the same:

Maybe there is a sequencing problem or maybe he is doing some kind of pitch tipping or has a release point that is easy to see. Because of the current numbers, and the injury concerns, Joba doesn't have much real value when it comes to the trade market, but I think he could be an interesting buy low guy. His command doesn't look broken, at least by average locations (he can still locate both arm side and glove side depending on platoon), and his stuff is still really good. Preferably, he gets the fastball up higher on average, but he has the tools to succeed, especially if he gets away from Yankee Stadium where he has struggled.


  1. If the Cubs trade Garza, and Carlos V, Joba could be an interesting buy low option if they wanted to give him a chance to prove himself in the rotation until the end of the year.

    It might take a Triple A stint to stretch him out.

  2. I disagree with your suggestion of moving him back to a starter. If he can't stay healthy in relief, then there is no reason to believe he will stay healthy as a starter. Plus he would have to bring back his changeup, something that is probably rusty.

    Anyway, thanks for reading Johnny.

  3. Great article. Fantastic amount of research was accumulated