NL East Rotation Showdown

So a mini-argument broke out on Twitter today. No one got hurt, fortunately, but feelings may have been bruised. It all started when radio host Kent Covington suggested that the starting rotation in Atlanta is better than the one in Philadelphia, which is not an outrageous claim in and of itself. However, he suggested that the Phillies’ duo of Roy Halladay and J.A. Happ is only marginally better than the Braves’ duo of Jair Jurrjens and Tommy Hanson.

As a proclaimed radio host, I’m sure his intention was just to ruffle some feathers. He did so successfully, as his Twitter feed is mostly a litany of responses to outraged Tweeters. I don’t write this to call him out, however. It was a thought-provoking claim and it broke up the monotony of the baseball-less winter.

Still, I was curious. Is the Braves’ rotation better than that of the Phillies? Which rotation in the NL East is best? To answer these questions, I took the PECOTA projections from Baseball Prospectus (using WARP) and each team’s starting five according to the playing time projections from Heater Magazine. Here’s what I found:

  • Phillies (Halladay-Hamels-Blanton-Happ-Moyer): 11.7 WARP
  • Braves (Hudson-Lowe-Jurrjens-Hanson-Kawakami): 10.2
  • Marlins (Johnson-Nolasco-Volstad-Sanchez-Miller): 8.1
  • Nationals (Marquis-Lannan-Olsen-Martin-Stammen): 5.4
  • Mets (Santana-Pelfrey-Maine-Perez-Nieve): 4.7

PECOTA thinks the Phillies’ rotation is tops, about 1.5 WARP better than the Braves’ five. Additionally, Roy Halladay and Cole Hamels are the top two pitchers in the NL East according to the projections.

A nifty chart for you visual learners (click to enlarge):

Note: Pitchers are ordered by WARP, not by probable spot in rotation.

Of course, these are just projections and the baseball season will never pan out exactly as the projections say they will.

Kent lost me when he attempted to put Jair Jurrjens on the same pedestal as Roy Halladay. In several Tweets, he said:

Didn’t forget a/b Halladay. Jurrjens posted 2.60 just ERA. Halladay has never posted an ERA that low in a full season.

Jurrjens has yet to prove he can be quite the innings horse that Halladay is, but my point is, Halladay isn’t 1995-Maddux.

Jurrjens had better ERA, opposing average, & fewer HR’s. Now then, I agree that Halladay had a tougher road in the AL East…
…& I’m not even saying that Jurrjens is better than Halladay. But when you look at numbers, it’s hard to make a credible…
argument that Hallday’s in a completely different class. The facts just don’t support that claim.

The only reason I highlight this is to stress the use of BABIP in analyzing pitchers. Frequent readers of this blog are likely tired of me harping on this, but it is so important. BABIP does not correlate from year to year. When that BABIP significantly deviates from .300 (the league average), barring an obvious explanation, we attribute that season to luck and label the season an outlier. Both Hamels’ 2008 and ’09 seasons were outliers thanks to the respective .270 and .325 BABIP.

Jurrjens last year had a .273 BABIP, which is nearly as low as Hamels’ in ’08. What makes it worse for him is that he didn’t have the favorable strikeout and walk rates (and subsequent K:BB ratio). Thanks to the depressed BABIP, Jurrjens was also able to strand an abnormal amount of runners — nearly 80% to be specific.

Jurrjens struck out a meager 6.36 and walked 3.14 per nine innings, a K:BB ratio of just over 2:1. It’s decent, but nothing awe-inspiring.

Halladay, meanwhile, struck out 7.83 and walked 1.32 per nine innings last year, which gave him a K:BB ratio of nearly 6:1. He had a BABIP of .313. As noted here, Halladay has compiled his eye-popping numbers in the most offensively-potent division in the Majors: the AL East. It is very reasonable to expect his numbers to improve given the weaker level of competition in the NL East.

In no universe, except the Bizarro universe, is Jurrjens comparable to Halladay. PECOTA puts Jurrjens at about 3 WARP in 2010; I will bet the under on that. Halladay is at about 4.5 WARP; I’ll take the over. And I’m not just being fannish — I’m the guy calling for a significant regression for J.A. Happ for reasons along the same lines as Jurrjens.

Tommy Hanson, on the other hand, had a .280 BABIP in 2010 and he’s an example of a pitcher we can reasonably expect to post a slightly below-average BABIP due to his high strikeout rate (8.2 per nine last year). Matt Swartz of Baseball Prospectus found the following:

Pitchers who are at least one standard deviation above average in strikeouts enjoy the benefit of even lower BABIPs than moderately high strikeout pitchers. These extreme power pitchers have overall BABIP of about .285, and this drop in BABIP is consistent among all four count types.

If I’m a Braves fan, I’m putting my eggs the basket of Tommy Hanson; not Jair Jurrjens. Anything that Tim Hudson, Derek Lowe, and Kenshin Kawakami give is dessert.