Baseball used to be just the National Pastime, but now, America’s greatest game belongs to the world. Official Opening Day rosters haven’t been decided upon yet, but there’s a good chance the percentage of players born outside the United States could top 30% for the first time in history, further cementing baseball as the most diverse of the three major American sports (if Canadian and U.S. players are considered “domestic”, baseball’s international participation is  also greater than the NHL’s).

Comparison of International Participation Among Major Sports

Note: For NHL, domestic includes the U.S. and Canada.
Source: baseball-reference.com (2011); profootball-reference.com (2011-12); NHL.com (2010-11); rpiratings.com (NBA: 2011-12)

For much of its first 100 years, baseball was mostly composed of American born players. However, when Jackie Robinson broke the color barrier in 1947, that started to change. Soon after Robinson’s debut, an increasing number of international players, particularly those hailing from Cuba, Mexico, and Puerto Rico, began filtering into the league. As a result, the percentage of foreign born players increased from 3.6% in 1947 to 9.0% in 1961, the first year of expansion.

Domestic vs. International Participation in MLB, 1901 to 2011

Note: Data is not continuous, but based on five-year segments.
Source: Baseball-reference.com

With more teams came the need for a deeper talent pool, so over the next decade, international participation continued to trend up, reaching 12.5% by 1976, even though the number of Cuban born players was significantly curtailed by Fidel Castro’s revolution. Filling the void left by the absence of Cuban players was an influx of talent from Venezuela and the Dominican Republic as well as even greater participation from Mexico and Puerto Rico.

For the next 10 years, the number of international players remained stagnant. Perhaps not coincidentally, that was also the first decade of free agency. With a ready of supply of proven major league talent now regularly available, perhaps teams became less inclined to spend on international scouting? Whatever the reason, the number of foreign born players began to increase again in the mid-1980s, right around the time free agent salaries began to skyrocket. Since that point, the trend toward greater diversity has continued unabated.

Percentage of International Players, By Country

Note: Data is not continuous, but based on five-year segments. Percentages are based on international segment only.
Source: Baseball-reference.com

In 2010, the international presence in the major leagues peaked at 28.2% (the all-time high based on Opening Day rosters was 29.2% in 2005). Considering the increasing number of high profile international free agent signings and gradual development of foreign born prospects, both of those rates could be eclipsed in 2012, but for how much longer will the trend continue?

One of the key components of baseball’s new CBA is a provision that effectively creates a salary cap for amateur international free agent signings. Although not as extreme as folding foreign born amateurs into the Rule IV draft, this new system could have similar effects. In particular, there has been concern expressed about whether budgetary restrictions placed on international signings will discourage teams from investing overseas (i.e., why fund an academy if the ability to sign the prospects is limited?). Worth noting in relation to this concern is that since Puerto Rican players were added to the draft in 1990, the number of major leaguers hailing from the island has declined from 3.4% of all players and 24.3% of international players to 2.2% and 8%, respectively, in 2011. Needless to say, if a similar effect results from the new CBA, the percentage of foreign born players in the majors could reverse course.

Not only has there been a significant increase in the number of international players, but baseball has also experienced demographic shifts within the domestic population. For the first 30 years of the modern major leagues, the Rust Belt contributed the highest percentage of players, with Pennsylvania, Ohio, Illinois, and New York leading the way. By the 1930s, however, warmer weather states like California and Texas, which not coincidentally hosted some of the best minor leagues circuits in the country, began to take over.

Domestic Participation in MLB, 1901-2011

Note: Data is not continuous, but based on five-year segments.
Source: Baseball-reference.com

Baseball’s state demographics remained relatively stable from the 1930s to the 1960s, at which point the number of players hailing from California and abroad began to take its toll on the rest of the country. More recently, however, the Golden State’s share of the player population has started to abate, dropping from nearly 25% in the mid-1980s to the current rate of 16.1%. This decline allowed the number of foreign born players to surpass the individual rates of every state for the first time in 1996.

Over the past five years, there has been an uptick in the percentage of players born in Texas and Florida, which seems like a trend that will continue. On the other hand, every other state now falls below the 3% level, meaning nearly one in two American born players is a native son of California, Texas, or Florida. Of course, it should be noted that those states have three of the four highest populations, but even on a per capita basis, they rank among the leaders.

Per Capita Domestic Participation in MLB, Top- and Bottom-10, 2011

Source: Baseball-reference.com and 2010 U.S. Census data

Despite the increased concentration among domestic players, baseball’s international presence has fueled its unprecedented diversity. This melting pot has been a recipe for success, not only on the field, but in the board room as well. So, the next time someone tries to argue that baseball is no longer the National Pastime, just smile and nod your head. They’re right. Baseball is now the International Pastime.