The Big Four in polo was the American polo team that competed for the International Polo Cup.
History
The term was first used in 1909 for the team of Devereaux Milburn, Harry Payne Whitney, Lawrence Waterbury, and James Montaudevert Waterbury, Jr.. The term was still in use for the 1927 team of James Watson Webb, Sr., Thomas Hitchcock, Jr., Malcolm Stevenson (polo) and Devereaux Milburn.
References
Big Four (polo) Wikipedia(Text) CC BY-SA