In a recent thread, a comment was made by FanInJapan about a different divisional alignment that would be favourable to the Jays. In a response, MjwW posited that defining West, Central, and East based on current MLB cities is very difficult due to the longitudinal locations of several cities.

This got me thinking whether I could devise a geographically-based definition for East, Central, and West teams based on the upcoming 2013 realignment, which will see the Houston Astros move from the NL Central to the AL West.

Did I do it? Find out after the jump.

Interestingly (ok, maybe not), the Astros' move actually defining the West-Central border easier than it is now. When the Astros make the leap, the definition of West for MLB purposes will be "any team located in a state that lies entirely to the west of the Mississippi River and does not border the river." In fact, only 1 central team (the Royals) will be located in a city that lies wholly to the west of the Mississippi, but Missouri does border the river, so the Royals don't need to be in the AL West. I would argue that this is a geographically sound definition for "West" for the purposes of divisional alignment.

Defining the border between East and Central is tougher, since Atlanta (NL East) is located farther west than Cleveland, Detroit, and Pittsburgh. Given that 2 AL Central cities and 1 NL Central city lie east of Atlanta, we cannot simply create different longitudinal borders for each league and leave it at that. We need to be more creative to find a solution.

Which I have done.

I will lay out my proposed MLB East-Central border verbally below. It will initially sound needlessly complex, but if you follow it on a map, you will see that it is actually fairly simple and makes some sense, closely following the contour of the American Eastern Seaboard, which travels in a NE-SW manner based on longitude.

Here is the definition of the border: Start at any point along the New York-Pennsylvania border (79 45' W longitude). The border follows this meridian northwards to the North Pole. Follow this meridian south until it meets the Virginia-West Virginia border. Follow this border southwest until the Kentucky-Virginia border. Continue southwest along this border until you reach the Tennessee-Virginia border. Go east to the Tennessee-North Carolina border and follow it south to Georgia. Follow the Tennessee-Georgia border west to the Georgia-Alabama border. Follow this south to the Florida panhandle and extend it down to the Gulf of Mexico.

As complicated as this sounds, MLB East is basically defined as anything east of the New York-Pennsylvania border's longitude until it reaches the West Virginia-Virginia border and then every team in a state south of that point that borders the Atlantic Ocean. The southern part of the East-Central border also closely mirrors the Monongahela-Jefferson-Washington-Nantahala National Forest complex in Appalachia.

So there you go - everything east of that line is AL/NL East, and everything west of it is AL/NL Central. Check it out on a map!