how does pref work

As long as you maximize your options, yes. If you pref 2 houses, as long as you acknowledge that you would accept a bid from either house, you are guaranteed a bid from one of them. It might now be the house you rank in first though, it depends on which house has you higher on their bid list, but you will get A bid. If you say you will only accept a bid from one of the houses, you’re not guaranteed a bid from them if you aren’t high enough on their bid list. If you only have one house left at pref and you say that you will accept a bid from them, you will get one from them

Most people want 2 houses for pref, but I had one that I liked and it was so nice! I knew what house I’d be in before I even went to pref and it was actually really cool to be able to look at the actives a know they would be my sisters. I didn’t mention it to them, obviously but I was so relaxed while other girls were freaking out.