Wednesday, July 06, 2011

Zack Greinke: A Cornucopia of Statistical Anomalies

Some observations:

1. Zack Greinke has a 7-3 record, but only a 5.66 ERA. This ERA is the second worst among National Leaguers with 50 Innings Pitched. This suggest that he has been very lucky, and pitched much worse than his record.

2. Zack Greinke has a 5.66 ERA, but a 2.94 FIP and a 2.15 xFIP (which is FIP, but with Home Runs calculated to 10.5% of fly balls). For comparison's sake, Roy Halladay has an xFIP of 2.40. For further comparison, when Greinke won the Cy Young Award in 2009, his xFIP was 3.09. This suggests that Zack Greinke has been very unlucky, allowing far more runs than his peripherals suggest.

3. Among NL pitchers with 30 IP, only Roy Halladay has a better strikeout to walk ratio. This suggests Greinke has been excellent.

4. Among NL pitchers with 30 IP, nobody has allowed a higher percentage of baserunners to score. This suggests Greinke has been abysmal.

What the heck is going on?

First off, the simple answers. Milwaukee has the 5th best offense in the NL, so it makes sense that any pitcher would have a W/L record that would exceed his ERA. Also, they have the fourth worst defensive efficiency in the league, so it also makes sense that a pitcher would underperform a FIP that is adjusted to the league, rather than team. Finally, the 15.5% of home runs on fly balls is almost 50% higher than league average. Given that his fly ball rates are actually lower than his career average, it seems like that portion is largely luck. Going against my tendency to speak in absolutes, I can state with certainty that Greinke's home run to fly ball rate WILL go down.

There's more going on here than a few extra home runs though. FIP analyzes a pitcher with his current (rather than expected) home run rate, and Greinke's is about half of what it should be. So why the disconnect?

The first assumption may be that Greinke has largely pitched either very well or terrible, with less middle ground, and a quick glance might lead one to stop there. In 12 starts, he has 5 with a game score of 60 or higher (topping out at 75), 4 with a game score of 39 or lower (bottoming at 15, yuck), and only three in between. In his four worst starts, he's given up more than half his runs. So he's pitched mediocre or better on a good hitting team 8 of 12 times, and has a 7-3 record? So when he stinks, he REALLY stinks - the nights where he doesn't have a feel for it, he gets shelled.

Let's dig deeper though. In those 4 worst starts, he's gone 16.3 innings, with four home runs, 7 walks and 21 strikeouts. That's too many home runs, but it doesn't seem like he's been 12.21 ERA bad according to those peripherals. In those bad starts, his striking out one of every 4.04 batters. That's lower than his season 3.30 rate, but still quite good, right along side Anibal Sanchez, better than Roy Halladay, Cliff Lee and Josh Johnson. His walk rate in those losses, is (somewhat freakishly) exactly the league average of one every 12.142857 batters. That's far below his full season rate of one every 21 batters. Just "average." His home run rate of one every 21.25 batters is awful in those four starts, which explains some of the badness, but not all of it. That's Brett Myers home run rate for the season. Brett Myers walks on of every 14.9 batters, and strikes out one of every 6.1, and he, in front of one of the few defenses worse than Milwaukee, has a 4.67 ERA. Hmmm.

Now let's look at Greinke's eight non-terrible starts. In 52 innings pitched, he has a 3.63 ERA, a tick above the NL average of 3.81. In those starts, he has 68 strikeouts, 7 walks and 6 home runs. Doesn't it seem like that pitcher with those numbers would be a quite a bit better than league average? First off, he's striking out one of every 3.07 batters, which is awesome. How awesome? Well, there are no NL starting pitchers anywhere near that number. The only two guys with 30 innings who have struck guys out more frequently are Craig Kimbrel (2.45 ERA), and Tyler Clippard (1.86 ERA). For another comparison, check out a couple Hall of Famers in their best seasons: Sandy Koufax struck out one of every 3.39 in 1965; Nolan Ryan in 1987 struck out one of every 3.22. Of course, they played in eras where batters made contract more consistently, so let's check a couple contemporaries as well: Pedro Martinez struck out better than 1 in 3.07 batters three times (1999, 2000, and the injury shortened 2001); Randy Johnson did it five times (1995, 1997, 1999, 2000 and 2001). Pretty impressive company. He's walked one of every 29.9 batters, a pace surpassed by only Roy Halladay (31.7) and Edward Mujica (31.0) to this point this season. His rate of a homer every 34.8 batters in these starts is worse than the league average, but far from terrible - it's a better rate than Wandy Rodriguez and Brandon Beachy, among others having an acceptable to good ERA.

So at his worst, Greinke is like a better version of Brett Myers. At his worst, he's like much better version of Wandy Rodriguez. So how in the world does he have a 5.66 ERA?

Refer to point #4: "Among NL pitchers with 30 IP, nobody has allowed a higher percentage of baserunners to score." 54% of the guys who get on base against Greinke end up scoring. The league average is 34%. Only seven other pitchers in the NL have allowed as many as 45%:

Zack GreinkeMIL874754.02%29.40021.0003.303
Aneury RodriguezHOU814251.85%23.36413.5266.119
Armando GalarragaARI703651.43%15.2319.0007.071
Pedro BeatoNYM412151.22%77.00012.8336.417
Randy WellsCHC693246.38%31.8339.0957.074
James Russell*CHC632946.03%21.88919.7006.793
Javier VazquezFLA1396345.32%28.64311.7946.468
Aaron HeilmanARI532445.28%20.85714.6004.710
League Average 34.44%42.50012.1435.313

Of the seven other pitchers on this list, six of them have ranged from mediocre to terrible. Only Pedro Beato has an ERA of under 4.50, but then you realize that he's given up 6 unearned runs, bringing his RAA to 4.81. Of the rest of the group, many walk too many batters - only James Russell walks fewer than one in fifteen. Aaron Heilman is the only who strikes out more than 1/6 of the batters he faces. Greinke does give up home runs more frequently than Beato and Randy Wells, but the pattern here is pretty clear - the other guys on this list have such a high rate of turning baserunners into runs is because they have simply pitched quite poorly. With Greinke, it's more than that.

If Greinke is allowing an abnormal number of baserunners to score, perhaps he's simply pitched much worse with runners on base, skewing his results. Here, I think, we are on to something.

GreinkeBAOBPSLG Average NL PitcherBAOBPSLG
Bases Empty0.2470.2870.430 Bases Empty0.2490.3110.392
Men On0.2740.3150.538 Men On0.2570.3310.389
RISP0.3430.3970.701 RISP0.2490.3390.379

Yikes. So, in general, it seems when the average pitcher has nobody on base, they will pitch more aggressively, leading to a higher SLG and a lower OBP. When a runner gets on base, the pitcher becomes more conservative, more willing to walk the batter in lieu of the big hit - particularly when those runners are in scoring position. Greinke? He's giving up an slugging percentage 60% higher with runners in scoring position than he is with the bases empty.

Some of this is certainly bad timing. With only 74 plate appearances with runners in scoring position, a couple home runs really jack up the numbers. It seems impossible to think that, over a full season, this wouldn't begin to even itself out. However, the issue may be one of pitching mechanics rather than anamalous statistics. In the fifth inning of his last start, Greinke was so uncomfortable pitching out of the stretch that manager Ron Roenicke visited the mound in the fifth inning and instructed Greinke to pitch from the windup, even with runners on base. Visually, his leg kick looks much smaller from the stretch. This is usual, but if it's interfering with his ability to get out the batter, they need to scrap it. A stolen base, on average, gives a player an 18-20% chance of scoring a run he wouldn't have otherwise scored. That's significant, sure, but not as significant as retiring the batter who, when hitting a home run, has a 100% chance of scoring himself and everyone on base ahead of him.

Greinke has had mechanical problems before. These problems, coupled with social anxiety disorder, resulted in Greinke almost quitting baseball back in 2006. According to all involved, the social anxiety portion is still completely under control, which is good news. Baseball men can be very good at putting players together again, but not necessarily people.

As far as Greinke's future, I think he will pitch better in the second half, if only by accident. Even acknowledging serious, serious issues pitching from the stretch, Greinke does enough things right in those situations that the home run/fly ball rate won't say so extremely high. Even if he doesn't solve the problems from the stretch, I think we'd see an ERA of 4.00-4.50 in the second half, which would be a serious improvement. If he manages to fix the problem from the stretch and be a bit luckier though? He would profile as a guy who could put up a sub-3.00 ERA and be the much needed complement to Yovanni Gallardo in the Brewers starting rotation in order to make a run at a championship. If that does happen, the Brewers rank just below the Phillies as the best bet to win the National League pennant. As always, "if."

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