I think it's even easier than that. I think you have point values for certain skills, if you combo them - then all you have to do it add. you don't need a specific numeric value for every unique combo of skills teams might suddenly come up with. In the case of the ball up - there is a point value for the ball up, there is one for the 360 and there's one for the tick-tock. What makes that skill so difficult is that is combos multiple things in one stunt - hence, just add the point values for each of those together. In that case, one person did all of it - if you can actually get multiple stunt groups to do it then you've set your difficulty on fire. It works with tumbling too. Two to a double gets you (at level 5) the difficulty points for a double, but an arabian, round off, whip full, whip double would get you points for the arabian, the full and the double in terms of difficulty in that one pass. If you have multiple people throwing it - you have increased difficulty on the whole.