International impact, and explanation of the term "World" Series
The title of this championship is confusing to some international readers, because the World Series is confined to the champions of two baseball leagues that currently operate only in the United States and Canada.
The explanation is that when the term "World's Championship Series" was first used in the 1880s, baseball was almost exclusively confined to North America, especially at a highly skilled (and paid) level. Thus it was understood that the winner of the major league championship was the best baseball team in the world. The title of this event was soon shortened to "World's Series" and later to "World Series".
The United States continued to be the zenith of professional baseball some decades into the 20th Century. The first Japanese professional baseball efforts began in 1920. The current Japanese leagues date from the late 1940s. Various Latin American leagues also formed around that time.
By the 1990s, baseball was played at a highly skilled level in many countries, resulting in a strong international flavor to the Series, as many of the best players from the Pacific Rim, Latin America, the Caribbean, and elsewhere now play on Major League rosters. The notable exception is Cuban nationals, due to the political situation between the USA and Cuba (despite that barrier, over the years a number of Cuba's finest ballplayers have defected to the United States to play in the American professional leagues). Players from the Japanese Leagues also have a more difficult time coming to the Major Leagues because they must first play 10 years in Japan before becoming free agents.
Early in 2006, Major League Baseball conducted the inaugural World Baseball Classic, to establish a "true" world's championship in the way the term is normally used for other international sports. Teams of professional players from 16 nations participated, and Japan won the first World Baseball Classic championship. Olympic baseball was instituted as a medal sport in 1992, but in 2005 the International Olympic Committee voted to eliminate baseball, and it will be off the Olympic program in 2012.
The World Series itself retains a US-oriented atmosphere. The title of the event is often presented on television as merely a "brand name" in the same sense as the "Super Bowl", and thus the term "World Series Championship" is sometimes used. However, the origin of the term lives on, as with these words of Frank Thomas in the Chicago White Sox victory celebration in 2005: "We're world's champions, baby!" At the close of the 2006 Series, Commissioner Bud Selig pronounced the St. Louis Cardinals "champions of the world". Likewise, the cover of Sports Illustrated magazine for November 6, 2006, features Series MVP David Eckstein and is subtitled "World Champions".
A recent myth has arisen that the "World" in "World Series" came about because the New York World newspaper sponsored it. There is no evidence at all supporting that hypothesis.