Hours of Daytona, 12 Hours of Sebring, and Petit Le Mans, which have featured in the World Sportscar Championship, IMSA GT Championship, Intercontinental Le Mans Cup, FIA World Endurance Championship, American Le Mans Series, Rolex Sports Car Series and currently the IMSA SportsCar Championship. Another one of the most popular forms of motorsports in the United States is the indigenous sport of drag racing. The largest drag racing organization is the National Hot Rod Association. Several other motorsports enjoy varying degrees of popularity in the United States: short track motor racing, motocross, monster truck competitions (including the popular Monster Jam circuit), demolition derby, figure 8 racing, mud bogging and tractor pulling. Golf Golf is played in the United States by about 24 million people. The sport's national governing body, the United States Golf Association (USGA), is jointly responsible with The R&A for setting and administering the rules of golf. The USGA conducts four national championships open to professionals: the U.S. Open, U.S. Women's Open, U.S. Senior Open, and the U.S. Senior Women's Open, with the last of these holding its first edition in 2018. The PGA of America organizes the PGA Championship, Senior PGA Championship and Women's PGA Championship. Three legs of the Grand Slam of Golf are based in the United States: the PGA Championship, U.S. Open and The Masters. (The Open Championship, known in the U.S. as the British Open, is played in the United Kingdom.) The PGA Tour is the main professional golf tour in the United States, and the LPGA Tour is the main women's professional tour. Also of note is PGA Tour Champions, where players 50 and older compete. Golf is aired on several television networks, such as Golf Channel, NBC, ESPN, CBS and Fox. Notable American male golfers include Walter Hagen (11 majors), Ben Hogan, Jack Nicklaus (record 18 major wins), Arnold Palmer, and Tiger Woods (15 major wins). Notable female golfers include Patty Berg (record 15 major wins), Mickey Wright (13 majors), Louise Suggs and Babe Zaharias. Tennis Tennis is played in the United States in all five categories (Men's and Ladies' Singles; Men's, Ladies' and Mixed Doubles); however, the most popular are the singles. The pinnacle of the sport in the country is the US Open played in late August at the USTA Billie Jean King National Tennis Center in New York. The Indian Wells Masters, Miami Open and Cincinnati Masters are