I was in a bunker and popped it onto the green 35 feet from the cup. As I was getting ready to putt, my friend told me that my ball was not in the bunker but instead was next to the rake in front of the bunker and I had played the wrong ball (both Xl-3000s). I went ahead and putt anyway and putt it 5-6 feet past the hole. I went back to where my ball was and played it. I chipped to almost exactly where my 35 foot putt was from. I putt this putt 2-3 feet away from the hole.

What is the penalty? Playing the wrong ball AND testing the putting surface? He was saying something about not even being able to play the original ball because I had already taken a stroke past the point of where the switch happened. I have never heard anything like this before but with the rules of golf, you never know! I couldn't imagine a rule in golf saying that you can't finnish the hole with your ball since not doing so is a big nono. Anyone know what he is talking about?

How would this differ if this was match and not stroke?