Park Factors: Through Six Weeks

The ones farthest away from what we expected are:

• Colorado, 191 points below expected. You all know this story: Rockies management has been keeping their baseballs in
  a 90-degree, 40%-humidity chamber. I think the hype on this is a little overrated; if those numbers are correct, that works out
  to a dewpoint of 65 degrees or so, which is typical for an un-air conditioned summer day in Baltimore. In other words, it isn’t
  that extreme of an environment.

  Furthermore, a humid ball still would face some problems of air density. A curve ball still shouldn’t curve as much, for
  example, no matter how wet the ball is. There could be a secondary affect, though, of softening the cover enough for the
  pitchers to get a really good grip on the ball and to get the seams to stick up higher. Whatever… run scoring in Colorado has
  essentially been normal this year, and not steroidal.

• Oakland, 172 points above expected. This one is a shocker, since Oakland is traditionally a pitchers’ park, and all
  of the other West Coast parks are hovering around their traditional ratings. The A’s have been this year’s Rockies so far,
  scoring 5.8 runs at home and only 3.3 on the road–the biggest differential of any team in the majors. Their schedule has
  actually been fairly balanced, featuring home-and-homes with Anaheim, Seattle, Texas, Chicago, and New York, plus homestands
  with Boston (good pitching) and Toronto (bad). Statistical fluke.

• Cincinnati, 162 points above. In 16 road games, the Reds have scored only 53 runs and allowed 46, an anemic 6.2 runs
  a game, the lowest figure in the majors. While their home numbers are a little high–at 10.0 runs per game, they rank third in
  the NL–it’s the road numbers that do it.

  Those 16 road games: four in Wrigley, which is posting its third consecutive season as a pitcher’s park, and three each in
  Dodger Stadium (traditional pitchers’ park with good pitchers this year), San Francisco (pitchers’ park), Pittsburgh (neutral),
  and Philadelphia (neutral to hitters). Once their road schedule starts to even out, with the Arizonas and Houstons, their park
  factor will move back towards normal. It is conceivable that construction of the adjacent Great American Ballpark has changed
  the characteristics of Cinergy Field.

• Atlanta, 129 points above. The Braves have scored just 3.1 runs per game on the road, worst in the majors, and their
  6.4 total road runs per game is behind everybody except Cincinnati. They have been well-balanced, outscoring opponents 96-95 in
  22 home games, being outscored 49-53 on the road. Part of the story is an anomalous 942 park factor in 1999, the lowest in the
  history of Atlanta baseball, holding down the "expected" score.

• Milwaukee, 116 points below. Now this one might be more than just a fluke of the stats, although the odds are still
  that that’s all it is. We don’t have a track record to look at here to decide what is "normal" for this stadium. It
  may be a domed stadium–OK, retractably roofed–but it has such an open design that even when the roof is closed you can get a
  lot of cold air inside it. Neither team has scored more than eight runs in a game at Miller Park this season, while six of the
  Brewers’ 21 road games have featured a nine-run effort or more, and those will even out during the season. Probably.

(Update, May 16. The Brewers and Reds just finished a four-game set in Miller Park, combining for 26 runs in four games. That
will keep Milwaukee on the pitching side and Cincinnati on the hitting side.)

Clay Davenport is an author of Baseball Prospectus. You can contact him by
clicking here.