Expected number of all-Confederate World Series

The World Series starts today. Atlanta vs. Houston. This is wrong for multiple reasons:

• the Astros are cheaters
• the Astros are a National League team
• as a native Philadelphian, I’m obligated to hate the Braves, even though I moved to Atlanta
• these are warm-weather teams and part of the fun of the ridiculously late postseason is that it’s not really baseball weather, but I just went for a walk and it’s pretty nice out.

Nathaniel Rakich observed that this is the first-ever World Series between teams from the former Confederacy. This surprised me! But there are only five teams in the former Confederacy, out of 30 in MLB (29 of which are in the US). In chronological order of formation, they are

• the Houston Astros (NL 1962-2012, AL 2013-present)
• the Atlanta Cobb County Braves (NL 1966-present, moved from Boston)
• the Texas (Dallas-area) Rangers (AL 1972-present, moved from Washington)
• the Florida/Miami Marlins (NL 1993-present)
• the Tampa Bay Devil Rays (AL 1998-present)

In particular Missouri never seceded, which matters quite a bit here because the St. Louis Cardinals have been in the World Series the second-most of any team.

First, a few words about Major League Baseball. There are currently two “leagues” comprising MLB, the National League and the American League. Each has 15 teams, of which one (the “pennant winner”) will make it to the World Series.

Organized baseball got started in the late 19th century, and its “classic” alignment of 16 teams were all in northern cities, since there were few large southern cities at the time. From 1903 to 1952 the teams were located as follows: Boston x2, Brooklyn, Chicago x2, Cleveland, Cincinnati, Detroit, New York x2, Philadelphia x2, Pittsburgh, St. Louis x2, Washington. In 1953-1972 a bunch of teams moved but since then MLB has mostly grown via expansion.

The former Confederacy is still is underrepresented in MLB – it has population of about 108 million, compared to the US population of 331 million, so it “ought” to have nine or ten teams. Or, if you’re going to argue that an MLB team has to be in a big city, nine of the thirty largest metropolitan areas are in the former Confederacy. (In order, they’re Dallas, Houston, Miami, Atlanta, Tampa, Orlando, Charlotte, San Antonio, and Austin. The first five have teams, and I believe the latter four have been thrown around as expansion candidates.) So although historically the country’s big cities may have been in the north, this is less true now.

Given the historical locations of the teams, how many all-Confederate World Series would we expect? We start counting in 1972, when the American League got its first team in the former Confederacy.

years	NL teams in former Confederacy	NL teams total	AL teams in former confederacy	AL teams total
1972-76 (5)	2 (Houston, Atlanta)	12	1 (Texas)	12
1977-92 (16)	2	12	1	14 (+Seattle, Toronto)
1993-97 (5)	3 (+Florida)	14 (+Florida, Colorado)	1	14
1998-2012 (15)	3	16 (+Arizona, Milwaukee)	2 (+Tampa Bay)	14 (+Tampa Bay, -Milwaukee)
2013-21 (9)	2 (-Houston)	15 (-Houston)	2	15 (+Houston)

So for example, in each of 1972-76, the chances of both pennant winners coming from the former Confederacy were 2/12 x 1/12 = 2/144. With the current alignment it’s 2/15 x 3/15 = 6/225.

The expected number of all-Confederate World Series is

5 x 2/12 x 1/12 + 16 x 2/12 x 1/14 + 5 x 3/14 x 1/14 + 15 x 3/16 x 2/14 + 9 x 2/15 x 3/15 = 0.978

which is honestly lower than I expected! But it’s only fairly recently that there have been an appreciable number of MLB teams in this part of the country, and the fact that you need teams from both leagues to get through really keeps this number down.