Most PGA players have their own caddies who they use for every tournament. These caddies have experience with the golfer, their swing, their game, etc., so they can offer insight during the match. They offer more to the golfer than just carrying the bag. From what I understand, the caddie that Kuchar used was a replacement provided by either the PGA or the course because his normal caddie couldn't make it. So I assume he was more of a "just carry the bag" kind of caddie. So is that worth the same 10% that a normal caddie is worth? Probably not. But if I just won over a million bucks, I think I would've been a bit more generous than that.