2a. Definition
A game of American tenpins consists of ten frames. A player delivers two balls in each of the first nine frames unless a strike is scored. In the 10th frame, a player delivers three balls if a strike or spare is scored. Every frame must be completed by each player bowling in regular order.
The above definition comes straight out of the USBC rule book. As you can see, a game is defined as having 10 frames, not twelve. Therefore, at best, a bowler is only allowed to have 10 clean frames per game.
So 30 clean is the best you can do...and yes that does mean you could strike in the 10th, and then not fill ten during the bonus balls (some may refer to that as an "open").
So unless someone wishes to re-define the USBC rule book, I think this issue can be considered closed.
