Well, this is my fifth day in sourceforts. Up until this, I had been copying strategies from other people, this is my first true invention (I'm pretty sure, if this has been done before, tell me).
This is something I invented yesterday, took this screenshot today when I redid it. It's on sf_sphinx. It would probably get ripped to shreds by an engineer if it wasnt defended, but its pretty fast, easy and not too block intensive for a secondary defense. Entry by jumping, exit by tunnel, but only for your own team. Muahahaha.