The most enduring American contribution to polo has been the creation of the handicapping system. This was set up in 1888 by H. L. (Henry Lloyd) Herbert so the teams could be more evenly matched and equalize tournament play. At that time, the maximum was 5 goals and there were only two players with that rating: Foxhall Keene and Thomas Hitchcock Sr., both of New York.
The attainment of a 10-handicap rating is extraordinary in the sport of polo. The 0-10 rating was established by the Polo Association of America in 1890, and in 1891 Foxhall Keene became the first 10-goaler in history. In England the maximum has always been a 10 rating since 1910 when the Hurlingham Polo Club Committee adopted the handicap system. It was then established by Argentina in 1911.
This system has continued, with minor modifications, to the present day. There is still no globally homogenous and all-encompassing system. The handicaps of players are determined by the respective country associations (mainly AAP, HPA, USPA). Only 5 (all Argentineans) are rated 10-goals by all three associations.
In the history of polo in the United States only 21 American born players have been elevated since 1891 by the USPA to 10-goal rated status for field play: (1) Foxhall Keene, 1891, (2) Thomas Hitchcock Sr., 1894, (3) John Cowdin, 1894, (4) Rodolphe Agassiz, 1894, (5) Lawrence Waterbury, 1900, (6) James Waterbury Jr., 1902, (7) Harry Payne Whitney, 1917, (8) Devereux Milburn, 1922, (9) Louis Stoddard, 1922, (10) J. Watson Webb, 1922, (11) Thomas Hitchcock Jr., 1925, (12) Malcolm Stevenson, 1929, (13) Elmer Boeseke Jr., 1934, (14) Cecil Smith, 1937, (15) Stewart Iglehart, 1939, (16) Michael Phipps, 1939, (17) Tommy Wayman, 1982, (18) Owen Rinehart, 1992, (19) Michael Azzaro, 1994, (20) Adam Snow, 2003, (21) Pablo Pieres, 2016.
Only 9 players from England since 1911 have attained a 10-goal rating (the last in 1939) from the HPA for field play: (1) Walter Buckmaster, 1911, (2) Edward Palmes, 1911, (3) Ralph Ritson, 1911, (4) Frederick Barrte, 1912, (5) Vivian Lockett, 1913, (6) John Hardress-Lloyd, 1913, (7) John Woodehouse, Earl of Kimberley, 1914, (8) Charles Roark, 1932, (9) Gerald Balding, 1939.
There was no Argentine born 10-goal player until 1943, when three players reached the highest AAP rating: Enrique Alberdi, Luis Duggan and Charlie Menditeguy. In 1944, two more players joined the 10-goal club: Juan Carlos Alberdi and Julio Menditeguy. Today there are 7 Argentine born players with a 10-goal rating: Adolfo Cambiaso, Juan Martín Nero, Pablo MacDonough, Gonzalo Pieres Jr., Facundo Pieres, Hilario Ulloa and Nico Pieres.
The Uruguay born David (Pelón) Stirling Jr. is rated 10-goal. Today only one American born player is rated 10-goal by the USPA. In 2016, Pablo “Polito” Pieres was the first American born player to be rated at 10-goal since Adam Snow in 2003. While Pieres is Argentinean, he was born in Connecticut and raised in Argentina.