Speed
Another point to choose shuttlecock is the speed. We use 75-78 instead. High temperature or high altitude, use slower shuttlecock.Low temperature or low altitude, use fast shuttlecock. For example, speed 76 ,77 in
Singapore, Hong Kong and Malaysia, Speed 77,78 in the U.S.A., Speed 78,79 in Finland, Canada, Korea and
Japan. Speed 79, 80 in Australia in winter. Speed 73-74 would only be played in high altitude area as Yunnan
Province in China and Colorado Springs in U.S.A. or high temperture area as Johannesburg in South Africa.