A writer at Purple Row, SB Nation’s Rockies blog, by the name of “RhodeIslandRoxFan” penned a very thought-provoking column yesterday in which he hypothesizes that either the Sabermetric stat wRC+ is flawed when it comes to accounting for the effect of Coors Field, or that the Rockies’ home park is responsible for a very noticeable competitive disadvantage.
For those not familiar, wRC+, or weighted runs created, is a Sabermetric statistic found at FanGraphs. The plus sign, similar to OPS+, indicates that the stat has been normalized such that 100 is average. wRC+ takes the various contributions a player makes — hitting singles, doubles, triples, and home runs; stealing bases; drawing walks — and converts it into one single statistic telling you how many runs a player contributed to his team’s offense.
RhodeIslandRoxFan illustrates the disparity between the Rockies’ home and road wRC+ dating back to 2002, both when FanGraphs’ data begins and when the Rockies introduced the humidor. On average, the Rockies have posted a 99 wRC+ at home and 82 on the road. The 17-point difference is staggering, as the next-biggest gap is nine points, posted by the Diamondbacks, Cardinals, Braves, and Pirates.
While it is tempting to believe that the stat is not accounting for Coors Field properly, RIRF shows that the Rockies’ home wRC+ doesn’t differ terribly from the league average at home on a season-by-season basis. However, the Rockies’ road wRC+ does vary from the league average on the road. RIRF concludes:
The road numbers on the other hand tend to support the idea that the Rockies are operating at a competitive disadvantage to all the other teams in baseball. Like a drug addict not being able to function when they come off a high without a fix, Rockies’ hitters don’t seem to be able to function properly when they come off the high of hitting at Coors Field.
Of course, this is one study and isn’t by any means conclusive and exhaustive, but the author makes a very compelling argument. If you enjoy well-reasoned analysis, check out the full article.