Suggestions

• What are the major professional sports leagues in the United States and Canada?

• Which major North American professional sports leagues use a draft system?

• What factors distinguish major professional sports leagues from other sports leagues?

• What is the player development process in North American sports leagues?

• What are the other prominent leagues in the United States and Canada?

• What are some related topics to the Big Four leagues?

• How long have baseball, American football, and ice hockey had professional leagues?

• What is the reference for the list of major pro sports teams ranked by market size?

• Which leagues are considered the 'Big Four' in the United States and Canada?

• What is the reason for the closed league system in North American sports?

• Which two leagues have higher concentrations of teams in the western United States?

• Which major league has no team based in a Canadian city?

• Which major league has teams in every U.S. market with over 4 million people?

• Which leagues have been short-lived in Canada?

• How do North American sports leagues differ from leagues in other regions?