Did you know the Rockies tend to put up big home and road splits? Of course you did. The Rockies are the very most important example of why park effects matter. Also, the most obvious. Over the past decade, Colorado ranks first in baseball in total runs scored at home, by more than 200. During the same period, the Rockies rank last in baseball in total runs scored away from home, by more than 100. Hitting in Coors is easy! Hitting not in Coors is hard. Or so the Rockies make it look, at least.
Coors Field just does strange things to baseball. It's not an unsolvable problem, and it might not necessarily be a problem, but it's something. Again, over a decade, the Rockies rank 14th in winning percentage at home. Meanwhile, they rank 28th in winning percentage on the road. If you look at the following table, you'll note that the Rockies are exceptional in this way. They experience either a home-field advantage, a road-field disadvantage, or both.
| Team | Home W% | Road W% | Difference |
|---|---|---|---|
| Rockies | 0.547 | 0.389 | 0.158 |
| Pirates | 0.512 | 0.378 | 0.134 |
| Brewers | 0.567 | 0.447 | 0.120 |
| Rays | 0.563 | 0.450 | 0.113 |
| Blue Jays | 0.554 | 0.443 | 0.111 |
| Astros | 0.494 | 0.385 | 0.109 |
| Cardinals | 0.601 | 0.498 | 0.103 |
| Braves | 0.579 | 0.483 | 0.096 |
| Tigers | 0.579 | 0.483 | 0.096 |
| Yankees | 0.622 | 0.531 | 0.091 |
| A's | 0.564 | 0.473 | 0.091 |
| Nationals | 0.522 | 0.432 | 0.090 |
| Reds | 0.544 | 0.456 | 0.088 |
| Red Sox | 0.589 | 0.501 | 0.088 |
| Padres | 0.528 | 0.443 | 0.085 |
| Indians | 0.539 | 0.457 | 0.082 |
| Mariners | 0.499 | 0.417 | 0.082 |
| Rangers | 0.555 | 0.478 | 0.077 |
| Twins | 0.525 | 0.451 | 0.074 |
| Orioles | 0.502 | 0.430 | 0.072 |
| D-Backs | 0.517 | 0.446 | 0.071 |
| Giants | 0.540 | 0.470 | 0.070 |
| Dodgers | 0.560 | 0.494 | 0.066 |
| White Sox | 0.535 | 0.473 | 0.062 |
| Cubs | 0.498 | 0.436 | 0.062 |
| Royals | 0.463 | 0.416 | 0.047 |
| Angels | 0.583 | 0.536 | 0.047 |
| Marlins | 0.494 | 0.448 | 0.046 |
| Phillies | 0.557 | 0.520 | 0.037 |
| Mets | 0.516 | 0.484 | 0.032 |
It's the Rockies, then the Pirates, some distance away. It's pretty obvious the Rockies haven't been as comfortable on the road as they have been in Colorado. Every team plays worse on the road, but the Rockies perform especially so, and because this is so consistent year to year, that causes people to theorize. Everyone wants to figure out why the Rockies have been so lousy away from home. Answer that, and maybe one could find a solution.
I remember reading, many many years ago, about a proposed Coors Field hangover. This was supposed to affect hitting, and the idea was that, upon reaching sea level, Rockies hitters would have to get re-accustomed to seeing pitches break normally. That is, in Colorado, pitches don't move like they do in other places, and Rockies players get used to that. So when they go on the road, normal movement looks like abnormal movement, and then it takes time to adjust. Time that the Rockies don't always have. I remember thinking the evidence was pretty compelling. Unfortunately I don't have a link, but what I do have is a re-examination. I wanted to look at this for myself. Have Rockies hitters just taken a few days to get used to conventional pitching on road trips?
I scanned 10 years of batting logs, and I threw out the occasional road trip that kicked off a season, before the Rockies ever played a home game. When I identified the road trips, I labeled each game as the first, second, third, etc. In the end, it was just a matter of grouping and math. Way I figure, even though this is a somewhat simple approach, if there's an effect, it ought to show up. This wasn't real promising, on the team level:
Team winning percentage
Sure, there's a little improvement, but it's from a 62-win pace to a 64-win pace. At the start of road trips, the Rockies have sucked. At the end of road trips, the Rockies have sucked almost just as much. But let's focus just on the offense, which is the whole point of this. This is an awful big table:
| Game | BA | OBP | SLG | OPS | BB% | K% |
|---|---|---|---|---|---|---|
| 1 | 0.246 | 0.309 | 0.384 | 0.693 | 7% | 22% |
| 2 | 0.237 | 0.303 | 0.356 | 0.659 | 7% | 22% |
| 3 | 0.243 | 0.311 | 0.382 | 0.693 | 8% | 22% |
| 4 | 0.239 | 0.310 | 0.382 | 0.691 | 8% | 21% |
| 5 | 0.250 | 0.316 | 0.391 | 0.707 | 8% | 20% |
| 6 | 0.223 | 0.293 | 0.360 | 0.654 | 8% | 22% |
| 7 | 0.252 | 0.313 | 0.383 | 0.696 | 7% | 22% |
| 8+ | 0.238 | 0.304 | 0.364 | 0.668 | 7% | 21% |
If there were a definite hangover effect, you'd expect the numbers to get better and better. As the Rockies' hitters adjust more and more, their productivity should get higher and higher. What we see here is ... practically nothing. Oh, sure, there's some bouncing around. There's a .707 OPS in there, for Game 5. There's an ugly .659 OPS for Game 2. The table isn't totally smooth. But then, this version of the same table sure is totally smooth:
| Game | BA | OBP | SLG | OPS | BB% | K% |
|---|---|---|---|---|---|---|
| 1 thru 3 | 0.242 | 0.308 | 0.374 | 0.682 | 7% | 22% |
| 4 thru 6 | 0.238 | 0.307 | 0.378 | 0.685 | 8% | 21% |
| 7 thru 11 | 0.244 | 0.308 | 0.372 | 0.679 | 7% | 21% |
That's almost inarguable. The batting averages stay almost exactly the same. Ditto the on-base percentages. Ditto the slugging. So, ditto the OPS, and the walk rates, and the strikeout rates ...
In case you're a visual learner, this might add some information, even though it's already been covered by the tables above:
There's one important thing I should point out: I've only looked at this information for the Rockies. So, I can't actually compare them to a league-average team. Though the Rockies' hitters haven't gotten better as road trips have gone on, it's possible that the average team actually hits worse and worse, which would support the initial theory. However, I find that unlikely. And the Rockies' numbers remain undeniably symmetrical. Basically, I don't see even a shred of convincing evidence that there's a hangover effect that gradually resolves itself over longer trips.
Which isn't at all to say that there isn't a hangover effect. Something might still be troubling these hitters. Perhaps it just doesn't fix itself as the Rockies play longer and longer away from home. When you play in Colorado, it's unlike playing anywhere else in the major leagues. Rockies players have to be prepared to play in Coors Field at least 81 times in six months. Maybe it just takes longer to forget what that's like. Maybe players need a change of scenery to get back to playing baseball like they came up to the bigs with. Dexter Fowler was able to adjust to playing in Houston. Seth Smith has survived Oakland and San Diego. Chris Iannetta has figured out sea-level baseball in Anaheim. Hitters aren't ruined once they put on a Rockies uniform.
Yet as they wear the Rockies uniform, they have all kinds of trouble hitting on the road, and there aren't any signs that gets better over one or two or three series. Some of this, surely, is just the talent level. The Rockies, by and large, just haven't fielded very good teams, and they've probably just looked a bit too good at home. But as for the Coors Field hangover, I might classify it less as a hangover, and more as a disease. This has been more than a two-day bug.
