A few words concerning the difficulty that golf champs (and a few others) face when it comes to defending their titles:
"The most difficult [titles] to defend will undoubtedly be golf. Just a year ago Chick Evans (1890 – 1979),Alexa Stirling (dates?), Ted Ray (1877 – 1943), and Jock Hutchinson (1884 - 1977) held the four main golf titles of the United States. Today not one of these survives with his title intact."