After being traded in part of the Mark Reynolds deal, going from the Orioles to the Diamondbacks, David Hernandez was one of the league’s most dominant relievers for two years, especially in 2012, when he struck out 35.3% of batters he faced. So far in 2013, his strikeout rate has dropped nearly 12% and while his walk rate hasn’t increased, he has become much more homer prone.
I think more interesting to the Hernandez story is that he was projected to be a mid-rotation starter in the big leagues the year before he came up. In 2009, the Orioles brought him up to be a starter, and he failed miserably. They eventually moved him to the bullpen where he had a decent year in 2010. He didn’t become the elite reliever however, until after the trade to the Diamondbacks. Looking at his average pitch locations by year (all pitches, entire graph is strike zone), I think we can see why he failed as a starter:
Hernandez had the problem that many young starters have, they work arm side very heavily and have problems finishing their deliveries and getting the ball to the glove side of the plate. As a reliever, he didn’t really start throwing the ball lower in 2010 and 2011, but got the ball more glove side, actually becoming a glove side pitcher in 2011, his first year with the Diamondbacks. In 2012, his really dominant season, Hernandez starting working more arm side (though not as arm side as he was when he was a starter), and lower in the strike zone on average. In 2013 so far, we see him getting even lower on average, but also more arm side. It is hard to imagine that the slight difference in 2012 and 2013 is the difference of being basically unhittable and extremely hittable. Hernandez is a four pitch pitcher, and really hasn’t changed his usage much from being a starter to a reliever, so let’s break down the rounded velocity and average location of each pitch, starting with the four seam fastball (I’m using the MLBAM tags for this post, and I am only look at 2009, 2012, and 2013 for these graphs, just for ease)
In both 2012 and 2013, he is throwing it in the same location, slightly higher and more glove side than he did as a starter. His velocity is down slightly this year, but he is locating it basically the same. It has been alarmingly ineffective, so much so that I don’t think the slight drop in velocity explains it. Hernandez also throws a moving/2-seam fastball (Brooks Baseball, with pitching tags done by Harry Pavidilis, combines all his fastballs into 4-seamers) according to MLBAM tags, and here is how he has located them in the three years we have been looking at:
This pitch hasn’t seen a real velocity decrease, but has also seen quite a regression in effectiveness. The locations show basically the same as what we saw with the 4-seamer, he is locating it the same in 2013 as 2012, higher and more glove side than he was as a starter. Basically, he is locating the pitch the same as the 4-seamer, so I think Brooks Baseball is probably right about Hernandez really just being a 3 pitch pitcher, with just one fastball. Hernandez’ most effective pitch, with this year being no exception, even though it has regressed heavily, is his curveball. In the minors, it was called a slider, and Baseball America said he had the best slider in the Orioles system two years in a row (along with the best breaking pitch in the AA Eastern League in 2008). However, both MLBAM and Brooks call it a curveball, and the movement data suggests that it is a curveball (not to mention the velocity)
Hernandez also locates the curveball like a curveball and not a slider, glove side and down, but not exclusively or dramatically glove side. Strangely, he is throwing the pitch harder and lower, and yet it is still less effective. Hernandez also throws a changeup very rarely (one of the reasons scouting sites thought he might not develop as a starter was because of the lack of changeup effectiveness and in 2009 it was clearly his worst pitch), and in 2013 so far, he is thrown it 28 times and not given contact on it so far. Just to complete the look, let’s see how he is locating the pitch
Arm side is usually good on the changeup, and it seems he has gotten more arm side as a reliever. In reality, Hernandez is basically a two pitch pitcher, and the velocity hasn’t really dropped dramatically on the fastball, and he is locating the same or better than he was in 2012, so why isn’t Hernandez having the same success? My next guess was release point, and there appears to be something there:
After giving up on being a starter, Hernandez started releasing the ball a little lower and further out. It was obviously working for him in 2012, and he had platoon splits, but was still good against lefties, despite being so far out and not having an effective changeup. This year, as he has moved further out and released the ball a little lower, he has been hit extremely hard by lefties. He is still striking some out (he actually has a higher strike out rate against lefties than righties), but he is walking a lot of them and giving up a lot of home runs.
The release point seems to be the difference for Hernandez so far this year, as he is locating the same and throwing roughly as hard. Why his release point has changed is another question. He is 28, so there shouldn’t be an age question, and he hasn’t cracked 70 innings since 2010, when he did make some starts, so usage shouldn’t be a question. He did pitch in the World Baseball Classic, but there is no way to say for sure whether that hurt him or not. For the meantime, it seems unlikely that Hernandez will return to his old self without changing his release point back to the 2012 average, so left-handed hitters don’t pick up the ball quite as easily.