Watson joined the Champions Tour in 1999, the same year he earned an honorary membership of the Royal and Ancient Golf Club of St Andrews in Scotland. He has 14 wins on the Champions Tour, including six senior majors, while playing a limited schedule of events. Watson shares with Gary Player and Bernhard Langer three victories for each in the Senior Open Championship. Watson revisited his 1977 Open Championship win at Turnberry with another win there in the 2003 Senior Open Championship. He followed this up with victories in 2005 and 2007.
