We had the referees rule on this during a practice match at the Florida regional. The rule is that for a tetra to be stacked it's apex must be six inches or less from the stacked tetra (or goal) below it. I leave the exact wording for the lawyer types.
In our instance both of our tetras were more than six inches from the supporting goal. Therefore, neither of them counted. It is possible, however, to get the bottom tetra within six inches of the supporting tetra (or goal) apex. The second one, usually, will not be stacked due to geometric constraints and all subsequent tetras will not count.
I'm Curie-ous to see how they rule it at the Championship.
