[Edxu]

If you really wanted to game the system, one thing you could do is have your ROBOT grab the cloth and instead of holding it open, simply hold it taut at an angle such that when the Human Player punts the ball through the embrasure, the cloth of the Low Bar behaves like a ramp, propelling the ball over.

Although it then causes some ambiguity over the definition of "open" and "closed": "not closed or barred at the time, as a doorway by a door, a window by a sash, or a gateway by a gate: " - Dictionary.com