Repost from YouTube: SFML 08 Patching Devices

In this case, the presenter, Ulf, when patching the Mac300, is choosing the next free DEVICE, and his first Martin is addressed at the fixture as 101, which is why he patched the 4 Martins starting at Device 3 address U1/101.
In the example it appears that the next free DMX address after he patches the Revolutions should be 94, but either through prep work or convenience,
or as a way to remember the address, he has skipped the next few DMX addresses to start the next series at DMX Address 101
So from the example in the video, the addressing should look like this:
Fixture Device #: Universe: Start DMX Address: Footprint

DMX Addresses - 1-30 are UnPatched/Unknown in the video. (Most likely 1-24 are conventional fixtures from SFML 07 video)
ETC RWM     Device:1      U:1     DMX:31     ftpt31
ETC RWM     Device:2      U:1     DMX:62     ftpt31
DMX Addresses 93-100 are UnPatched Addresses - Space for spares, or room to start the next Device group on an easy to remember
MARTIN Mac300 M4     Device:3     U:1      DMX:101     ftprt13
MARTIN Mac300 M4     Device:4     U:1      DMX:114     ftprt13
MARTIN Mac300 M4     Device:5     U:1      DMX:127     ftprt13
MARTIN Mac300 M4     Device:6     U:1      DMX:140     ftprt13
Next Free or Unpatched DMX Address is 153

Hopefully, I've understood your question correctly, and I hope this helps.