He makes up the rules as he goes. Just like how he runs the country.
President Clinton was well known for cheating at golf. Taking 6 foot "gimmies", pulling the Judge Smails routine of having Secret Service agents kicking his ball out of the trees, etc.
I've been playing golf since I was a small child, competed in a lot of tournaments, and have worked as an instructor. 0bama may be an avid golfer, but the dude clearly can't play golf or throw a baseball. Apparently he's good at shooting hoops...he should stick with that.