Whereas, I can see a caddie getting a percentage of a player's purse since they are on the bag during play.   But, if, Tiger is smart Sean would be on a contract which stipulates a set salary or commission with a bonus at the end of either a calendar or fiscal year.     The bonus would be greater if Tiger wins major(s).       lol

Steve Williams made over 8 million dollars caddying for Tiger in their 12 years together

Hank Haney claimed that he was only paid like 50,000 a year from Tiger. Stevie was paid 1,000,000.00 a year to caddy.