The Cincinnati Masters or Cincinnati Open is an annual outdoor hardcourt tennis event held in the
Cincinnati suburb of Mason, Ohio, USA. The event started on September 18, 1899 and is the oldest
tennis tournament in the United States played in its original city. The event is the biggest summer tennis
event in America as its men's portion is one of nine elite Masters 1000 tournaments on the ATP World
Tour and its women's event is one of five Premier 5 events on the WTA Tour.