The Curious Case of Zack Greinke

As I sit here and watch the AL beat up on the NL in the All-Star game (for the 8th straight time) I can't help remembering the high hopes we Royals fans had for Zack Greinke this season. Even though I wasn't as optimistic as some because of what I called Greinke's "old pitcher skills" (which are a good thing), there is no way I would have forseen the collapse which ended with 20 hits and 10 earned runs in his last 10 and two-thirds innings pitched.

For the season he has a 6.20 ERA and given up 126 hits in 97.1 innings, walking 26 and striking out 58 while giving up 11 homeruns and sporting a 1-11 record. As you can imagine when compared with last season his walks per inning pitched are up from 1.6/9 IP to 2.4/9 IP, his strikeouts are down (6.2 to 5.4), his strikeout to walk ratio is down (3.85 to 2.23) but his homerun rate is also down moving from 1.6/9 IP to 1.0/9 IP. I'm also encourage that his ground ball to fly ball ratio has increased from 0.81 in 2004 to 1.05 this season. Although his walks have increased and his strikeouts have decreased he still has very respectable ratios of both and when combined with his low homerun rate and increasing ground to fly ratio it kind of makes you wonder how he could have given up so many hits.

A quick look at The Hardball Times stat pages provides three clues to the answer. First, Greinke's line drive percentage is 21.7%. That places him third behind only Bruce Chen (24.5%) and John Lackey (23.7%) in the AL. Line drives become hits 75% of the time whereas groundballs are converted into outs 75% of the time. If Greinke had given up the league average of 18% line drives he would have given up 9 or 10 fewer hits which may translate into a handful of earned runs saved. Last season he gave up just 16% line drives. One of the cautions about Greinke I mentioned previously was that he doesn't have an "out" pitch and so his ability to locate his pitches and change speeds become even more important. If his location starts to suffer it follows that he'll get hit harder as evidenced by an increasing line drive percentage.

Secondly, the Defensive Efficiency Rating (DER) behind Greinke this season is just .667. In other words the Royals defense converts balls put into play into outs when Greinke is on the mound 66.7% of the time with the league average being around 69%. Tops in the AL is Jose Contreras of the White Sox who has as DER of .764. Certainly, some of that difference is the fact that Greinke has given up more line drives but not all. The Royals defense has played a role. And that leads us to the most important clue and that is Greinke's FIP. FIP stands for Fielding Independent Pitching and is an attempt to measure those things for which a pitcher is responsible for and estimate what his ERA "should" be all other things being equal. FIP is calculated as:

FIP = (HR*13+(BB+HBP)*3-K*2)/IP

plus a league-specific factor usually around 3.2. Greinke's FIP is 4.47 which is a difference of -1.73 from his actual ERA. Only Jose Lima has a bigger difference. So why is the difference so large? You'll notice that hits aren't included in the calculation of FIP since things like walks, strikeouts, and homeruns are a better predictor of pitching performance than hits given up since there is more variability in whether a batted ball is converted into an out or not. And in 2005 Greinke's batting average on balls in play is near .340. Some of this is due to his high line drive percentage, some to poor defense, and some to plain bad luck.

So in short, Greinke's performance in 2005 has been disappointing but not quite as disappointing as a 6.20 ERA might indicate. I'd look for some improvement in second half.