Multi pitch trad: belaying from the top, preparing for immediate subsequent rappel??

I spent the past weekend with a guide who gave me some pointers on improving efficiency in multi pitch trad.

He was explaining a technique of using the rap rings on a climb to belay up your second to speed up the rappel process. Essentially, he threaded the rope through the rap rings and coiled one side of it and then moved down towards the edge of the cliff and tied a masterpoint, belayed off that and his second climbed up and was able to immediately rig himself for rappel.

Does anyone know what I'm talking about? Looking for a video or diagram explanation. I can't quite remember the process!

This is often called the "camp bird road" for obvious reasons. It works well in specific circumstances. It's a bit overkill for most objectives, and if you really need that speed you'd want to counterbalance rap.

It isn't really trad unless it's a walk-off. :)

No thanks ! If you need to get down in a hurry 2 biners clipclip and off you go..The method you were shown also doesn't allow an endknot ???

Makes sense and sounds quick.
However, if I understand correctly, the guide is not clipped into anything when she undoes the powerpoint, pulls the rest of the rope though and puts her plate on to rap. Or does she pull the rope through the ring to the midpoint of the rope before she ties the powerpoint. The latter would only work it the pitch was less than half a rope length.

Don't really see how this makes it any more faster. It just means he already did work before the second got up to the final anchor but does that make doing it before hand any faster than just doing it at the end?

The amount of time saved probably wouldn't make any major difference in the day unless you were doing a ton of 2 pitch climbs than maybe by the end of the day you would save enough time for 1-2 more pitches.