spin since alone, it is not only less effective but also harder to produce. Competitions Competitive table tennis is popular in East Asia and Europe, and has been gaining attention in the United States. The most important international competitions are the World Table Tennis Championships, the Table Tennis World Cup, the Olympics and the ITTF World Tour. Continental competitions include the following: European Championships Europe Top-16 the Asian Championships the Asian Games Chinese players have won 60% of the men's World Championships since 1959; in the women's competition for the Corbillon Cup, Chinese players have won all but three of the World Championships since 1971. Other strong teams come from East Asia and Europe, including countries such as Austria, Belarus, Germany, Hong Kong, Portugal, Japan, South Korea, Singapore, Sweden, and Taiwan. There are professional competitions at the clubs level; the respective leagues of Austria, Belgium, China (China Table Tennis Super League), Japan (T.League), France, Germany (Bundesliga), and Russia are examples of the highest level. There are also some important international club teams competitions such as the European Champions League and its former competitor, the European Club Cup, where the top club teams from European countries compete. Naturalized players in international competition According to the New York Times, 31% of the table tennis players at the 2016 Summer Olympics were naturalized. The rate was twice as high as the next sport, basketball, which featured 15% of naturalized players. Feng Tianwei, a Chinese-born player representing Singapore, has medaled in three Olympic table tennis events, more medals than native Singaporeans have won in all other sports combined (two). These successes have been somewhat controversial in Singapore. In 2014, Singapore Table Tennis Association's president Lee Bee Wah quit over this issue; her successor, Ellen Lee, later favored the application for citizenship of Zeng Jian, a China-born paddler. The rate of naturalization accelerated after the ITTF's 2009 decision (one year after China won every possible Olympic medal in the sport) to reduce the number of entries per association in both the Olympics and the World Table Tennis Championships. In 2019, the ITTF adopted new regulations which state that players who acquired a new nationality may not represent their new association before: 1 year after the date of registration, if the player is under the age of 15 when registered and has never represented another association 3 years after the date of registration, if the player