The number of clubs with paid contracts rose, and both the Board and the game professionalized. In 1910, for the first time a country tournament involving more than two national teams was held, although it was informal and not officially recognized by CONMEBOL. The three matches of the Copa Centenario Revolución de Mayo, between host Argentina, Chile, and Uruguay, were played in May and June. Argentina was the unbeaten winner. This tournament is also considered the first Copa América, or its direct precursor. The official first edition of the Copa América, at the time called the Campeonato Sudamericano de Fútbol, was organized by Argentina in 1916 to commemorate the centenary of the Argentine War of Independence (1810–1818). Four countries took part, with Brazil invited in addition to the previous participants. Uruguay won two matches, emerging as the first South American champion. The then 19-year-old Isabelino Gradín was Uruguay's best player, and the tournament's top scorer, with three goals. A day after Uruguay's big victory in Chile, the Chilean Football Federation demanded reversal of the results, on the grounds that two Africans were on the Uruguayan team. Gradín, who had scored twice in that match, was one, as his great-grandparents had been slaves from Lesotho. Chile's protest was ultimately rejected, and Uruguay declared the rightful winner. The Uruguayan team went on to win six of the first ten editions, losing the final once and facing protests from Chile on two occasions.