# Jordan Zimmermann and the Luck Dragon

In the last two posts I've written I declared that Tyler Clippard was fine and that Nate McLouth should be seeing better results based on his contact rate. Since the Clippard post the Nationals reliever has pitched 14.2 scoreless innings in a row and after the post mentioning McLouth, the outfielder went 4-4 with a walk, a double and a stolen base. Clearly with such a large sample size of evidence we can conclude that my writing about a player's struggles instantly makes them better. Therefore, I have decided to apply my indisputable powers to tonight's starting pitcher Jordan Zimmermann. After 11 starts this year Zimmermann is in the possession of a very un-Zimmermann-like 4.07 ERA. To say this is a problem is an understatement in need of hyperbole. This has led many a fan to ask, what's wrong with Jordan Zimmermann?

At first glance the answer is simple: nothing. Zimmermann's FIP- (fielding independent pitching adjusted to league average) is 88, just a touch below his career average of 90 and about 12% better than league average. Additionally, his strikeout rate (19.4% 2014, 19.5% career) and BB% (5.0% 2014, 5.3% career) aren't out of the ordinary and his K%-BB% of 14.2% is well above league average of 12.3%. The best indicators of a pitcher's performance are right in line with Zimmermann's career averages. Nothing to see here.

Even at second glance the answer seems to be the same. When we drill down to the root of Zimmermann's pitching this year we see the same pattern. His average fastball velocity according to PITCHF/x is 93.7 miles per hour, right in line with his career average of 93.5 miles per hour and his average velocity in 2013 of 93.9 miles per hour. Hitter's plate discipline numbers against Zimmermann offer no solution either. As measured by PITCHF/x, his O-Swing% (33.7% 2014, 33.2% 2013) and Z-Swing% (63.5% 2014, 63.2% 2013) are almost exactly the same as they were last year. And opposing hitter's contact rate is actually down to 78.7% this year from his career average of 82.6%. That contact rate is explained more by this next stat. Below is a graph of his SwStr%+, a quick number I calculated that adjusts swinging strike rate to league average and indexes it so that 100 is league average.

As you can see, Zimmermann's SwStr%+ this year is up a little over 20 percentage points from 2013. Opposing hitters are swinging and missing more often at Zimmermann's offerings than ever before. Again, we're stymied as to why Zimmermann isn't seeing his typical production on the mound.

At third glance we turn to the two stats that Bradley Woodrum dubbed the Luck Dragons in a series of videos: LOB% and BABIP.

[embed]http://www.youtube.com/watch?v=ggFArD4tffk&index=2&list=PL5E48608074387D54[/embed]

Zimmermann's LOB%, or his percentage of runners stranded, is 71.1% this year. This is below both his career average 74.3% and the league average of 73.1%. He has had even more problem with his BABIP. Zimmermann has allowed an astounding .369 batting average on balls in play in 2014, well above his career average of .295 and the league average of .294. So we can just chalk it up to bad luck and get on with our day right? Wrong.

There's one more piece of evidence I would like to submit to the court. Mark Simon of ESPN Stats & Info tracks a stat he has dubbed HHAV, or hard-hit balls average, which tracks the percentage of at-bats that end in a hard-hit ball. The stat is measured similarly to defensive stats like DRS, a trained observer reviews each at-bat of a game on video and marks whether it ended in a hard-hit, medium-hit or soft-hit as defined by the trackers. It is a subjective stat, but can still give a fairly accurate picture of the sort of contact a pitcher is giving up. Below are the rankings of pitchers who gave up the most hard-hit balls Simon published last week.

[embed]https://twitter.com/msimonespn/status/470950655067439105[/embed]

By this measure Zimmermann is giving up the seventh highest percentage of hard-hit balls among pitchers qualified for the ERA title. So we can't chalk up all of his BABIP and LOB% problems to luck. Opposing hitters seem to be squaring up Zimmerann's pitches more and driving them and it doesn't take a baseball genius to know that harder-hit balls lead to more hits. Zimmermann's line drive rate of 23.1% this year, up from his career average of 21.1%, would seem to corroborate this. So what's the verdict?

Considering that almost all of Zimmermann's peripheral numbers beyond HHAV and LD% are either in line with his career average or better it seems likely that his overall production will improve as the year wears on. The number of hard-hit balls he's allowed so far isn't something that can just be waved away, but there doesn't seem to be anything behind it. Zimmermann's velocity is the same and his Zone%, the number of pitches inside of the strike zone, is 54.0%, not too far off his career average of 55.5%. With everything in mind, the safe bet with a pitcher like Zimmermann is that his ERA will fall to a more Zimmermann-like number by the end of the year.