The inaugural race was held in 1911 and was won by Ray Harroun. The event celebrated its 100th anniversary in 2011, and the 100th running was held in 2016. The event was put on hiatus twice, from 1917 to 1918 due to World War I and from 1942 to 1945 due to World War II. Takuma Sato is the current champion. The most successful drivers are A. J. Foyt, Al Unser Sr., and Rick Mears, each of whom has won the race four times. The active driver with the most victories is Hélio Castroneves, with three. Rick Mears holds the record for most career pole positions with six. The most successful car owner is Roger Penske, owner of Team Penske, which has 18 total wins and 18 poles. Penske also has five wins at the IndyCar Grand Prix, held on the combined road course.