Denver is where pitchers' peripheral numbers go to die.
Humidors and huge outfields have mitigated the issue a bit, but that's still the first thing that comes to mind for most stat heads when the words "Coors Field" are uttered: Oh, those poor, poor pitchers.
There's evidence, though, that the ballpark messes with hitters, too. Rockies hitters have the biggest home/road splits in baseball over the past five years ... even after you correct for park effect. By weighted runs created plus, they're 17 percent worse on the road than at home, whereas the league average home and away split is 10 percentage points lower.
In other words, Coors Field seems to giveth at home and taketh away on the road. When I asked Rockies hitters about this and checked the numbers, a clearer picture emerged: The Rockies are pitched differently at home, and their response to that difference seems to lead to problems on the road. All along, we thought pitchers were the only ones negatively affected by playing half their games at Coors Field; turns out, hitters are affected, too.
Let's get to the root of what's happening. First, we'll look at how things are different at home, then explain how it's affecting the Rockies' performance on the road (at least those not named Nolan Arenado, who actually has more home runs and a higher OPS on the road this season).