Andy Bug Guide.
Basically, the basic bug is when Andy drops a ring, they will usually be set or unique, sometimes rare, but never magic, therefore if u need rings, shes the girl to visit.
The other bug is that if you kill her when someone else has kill credit, then she will keep dropping uber items.
However, I havent seen any proof of this.
I completed 20 runs like this and found better than average stuff, compared to normal andy runs, so thats not exactly conclusive.
I made up a spreadsheet, and from memory, there were about 10% more set items, and 10% more uniques than normal.
I noticed that a lot less blues dropped, i.e. the stuff was usually at least yellow, if not gold.
Obviously 20 runs is not conclusive, more testing will have to be undertaken.
How its done :
Make a character - goto Hell, get Catacombs 2 waypoint.
Dont kill Andy -
exit game.
Join a Baal run game ( here the creater must of killed Andy )
Kill Andy
( u wont get kill credit, however she should drop better than a normal andy drop)
exit game, repeat.
Im not sure how much better an Andy Uber drop is supposed to be over a normal Andy drop, I think the only difference is about a 10% better chance of rare/unique/set kinda like if u had say another 50-100% mf on your character maybe.
someone can clarify this though