I got the June ACBL Bulletin today and I was browsing. I want to stay on the right side of copyright laws so I will take it easy, but I doubt anyone would mind if I grab a couple of suggestions.
Larry Cohen has an article on pp 49-50 where he discusses, among other things, fourth seat openings at the 2 level. He suggests this be on "roughly 10-13 HCP". I mention this because in IAC I have from time to time encountered people treating it as something like 15-17. What LC suggests is, I believe, very standard. I think of it this way: If I open 2S in fourth seat I figure that if the unseen points are distributed reasonably then I can have a good chance of making 2S. Moreover, I don't much expect partner to be making a game try unless his hand is exceptional I wish to play 2S. I expect LC would not much quarrel with this formulation.
I have, at various times, bemoaned the clash of expectations in pick-up games in IAC. I am hoping some posts such as this could help clear things up. If a pair, by agreement, wants to play that a fourth seat 2S is 15-17, or whatever they wish, of course that is their business. But if not discussed, I think LC is stating the default.
I am thinking to put up a few more of these with the same general flavor.