For a beer I owe you of course a good explanation. Aside from the detrending modes, you can invert or randomize the price curve with Detrend. Inverting is just for testing if the system still works when the trend goes in the other direction. SHUFFLE is for reality checks. You can find an example when you download the "boersenhackerbuch" scripts from my blog. The script "Alice4b" uses this feature for a reality check of a system similar to workshop 7.