The Rockies are
batting .273/.340/.431 at home vs. .263/.332/.429 on the road. They're scoring 4.9 runs per game at home and 4.6 runs per game on the road.
Maybe the visiting pitchers have figured out Coors as well as the Rockies pitchers have, although it seems unlikely that the whole league would get it at the same time.
You have to understand the magnitude of this change. It would be like the
entire league dropping 30 or 40 points of batting average
at the same time. By way of comparison:
Rockies Slugging Percentage
Year Home Road
1993 .482 .362
1994 .479 .401
1995 .556 .384
1996 .579 .357
1997 .523 .432
1998 .519 .401
1999 .549 .390
2000 .538 .368
2001 .554 .410
2002 .496 .348
2003 .503 .388
2004 .506 .403
2005 .460 .359
2006 .431 .429
On average, over the past 13 seasons, the difference between home and road slugging for the Rockies was
134 points. This season, it's two points.
This season, the Rockies have their second-best road slugging percentage in club history. But their home slugging percentage is by far the worst in club history, by 29 points.
Maybe clubs have figured out Coors. Maybe it's a statistical anomaly. Maybe it's the humidor. Maybe's it's the weather.
I don't know what it is. But it's as significant a difference as between the deadball era and the lively era was for baseball as a whole. It's not some minor blip.