It's an old farming tactic that's probably obsolete now.
Many updates ago, shortly after the loot penalty was put in place, people realised you could go to 0 trophies and raid with no loot penalties. SC obviously added the loot penalties to start from 1 trophy and at 0 trophies it was farming paradise. Then some nubs caught onto it, posted it on the forum and then of course the next update made it impossible to get to 0 trophies. This is SC's forum so anything you post here gets nerfed so people making all these farming help topics are shooting themselves in the foot because they will close whatever tactics you are exploiting if you outline it all here.
So now the new update was out stopping 0 farming, at just under 200 trophies you found the bases you tried to dump one troop on no longer gave a negative trophy so sub 200 farming was born because that was as low as you could go. I was TH9 and raiding other farmers using only giants, wallbreakers and goblins. The giants would roam the bases with all their defence targeting them while the goblins grabbed all the loot for under 30% damage when done properly. The idea was to always stay under 40% damage so you could continue raiding the same bases and also maintain the low level of trophies. It wasn't farming noob bases with no walls, it was farming weaker farmers.
Nowadays, it's possible to go to 0 but the loot is no longer uncapped so the whole under 200 thing is kind of obsolete these days and the people that go down there with TH8 and 9 are only raiding other farmers down there. Like the original post mentioned, you can't go offline and stay down there. You have to stay online to maintain the low trophy count and in all honesty you will find better and easier loot at 1200+ and won;t need to stay online to play.
