Caddies get a weekly paycheck, no matter where their player finishes. This weekly salary is negotiated with the player and can range from $1,000-$3,000 a week.
This base salary is meant to cover basic travel and living expenses.
As a rough rule a caddie also will earn 5% of the winnings if his golfer finishes outside of the top 10 and 7% of the winnings for a top 10 finish.
A caddie usually earns 10% of winnings when his golfer wins a tournament.