Someone can find more information about pennants for situations such as sporting events and teams at a company that makes pennants for your sports team, or at the online blogs of the people that have experience with pennants.
Custom made pennants can be purchased used off of eBay, or from certain manufacturers. Companies that produce pennants usually focus on sports, but custom-made pennants can be bought from independent designers.
The Los Angeles Dodgers have 18 National League Pennants second to the New York Yankees with 40 Amearican League Pennants. The Oakland Athletics have the second most in the American League with 14 pennants.
The Yankees have won 40 American League pennants.
The Oakland A's have won 15 American League Pennants in their history.
Since 1950, the Yankees have won 24 American League pennants.
Boston
The New York Yankees won 40 American League pennants. That is the most in major league baseball.
The first known pennants appeared at ballparks at the turn of the century, and from 1905-1910 the first pennants bearing team or city names were produced. The first World Series pennant for the Boston Braves appeared in 1914. In the 1970's the traditional felt pennants were replaced by Synthetics which were added to the fabric, making a stronger, thinner, and less expensive pennant. For more information on vintage baseball pennants visit the link I left below.
The Dodgers franchise has won 21 National League pennants, 9 of which came in Los Angeles: Pennants in Brooklyn: 1956, 1955, 1953, 1952, 1949, 1947, 1941, 1920, 1916, 1900, 1899, 1890 Pennants in Los Angeles: 1988, 1981, 1978, 1977, 1974, 1966, 1965, 1963, 1959
Cardinals
The Yankees won five pennants during the 1930's.1932, 1936, 1937, 1938 and 1939.