If you've ever heard an announcer reference the ever horrific west coast road trip you'll know exactly what I'm talking about when I say the idea that east coast teams generally lose on the west coast has been instilled into your membrane. In theory it makes sense, after all the players are experiencing time zone changes, long travel time, and general proneness to losing focus. However, why is it that we never hear about the west coast teams traveling close to the Atlantic? After all they're the ones losing three hours - the east coast teams technically gain rest.
What about subsequent trips to either coast? Are teams more prone to winning earlier in the seasons or during the late season roadies? With those questions in mind I decided to do some schedule searching and tally the wins and losses on each road trip. I went against including runs scored and allowed totals because for the large part it was dependant on who the team was playing, for example playing at the Padres is quite a bit different than playing in Colorado.
As you see the western seaboard teams faired better than their counterparts on the road which defies a bit of logic. Consider that the combined team records were 1049-1057 (roughly .500) and 680-618 (roughly .520), that should suggest the two sides coming close to a split in winning percentage, but reality doesn't see things that way, holding the east coast teams to a .410 winning percentage and the west coasters to a .520 percentage.
One reasoning behind the split is that the weaker teams in the east played more west games. The Pirates and Reds - winners of a total of 16 west coast games and 140 regular season games) played the most out west, a combined 47 games. Meanwhile the Angels, Dodgers, Rockies, and Diamondbacks played the most games in the east; all of those teams won at least 82 games last year.
Another theory would be that it's purely luck - after all most ballparks out west are bigger than the ones in the east, or how about that most of the east coast games for the western teams come late in the season, after they've made subsequent trips to the border? Perhaps teams are more comfortable or just overall better? After all by the third swing across the country I imagine most teams have tweaked their rosters quite a bit since spring training.
The exact cause for the difference is unknown, but at least we know the theory that east coast teams aren't so hot out west is actually true, a bit surprising if you ask me, but even more so surprising is that west coast teams don't seem all that bothered by playing on the east coast.