[wickedbid1]

I like to play 1nt forcing, and put opening 1nt as 14+ to 17- in my profile. This gives me maximum flexibility with those awkward hands.

With a balanced 14 count & a 5ve card major, i usually open 1M. If the hand has a couple tenaces that need protecting & will generate extras, i may upgrade to a 15 count. (i also giv weight to texture -- 10s & 9s)

With 15-16 (the range that would accept an invite) I open 1nt to keep these hands out of the major opening. They r too weak to take two voluntary bids on, in my opinion. Yet one rarely will be in the wrong contract if opener has at least invitational values (one can show the 5 crd major "on the way" to 3nt), and the 15-16 hcp generally means 1nt is playable, tho not always ideal. Ther r many hands which will score about as well in one or the other, or that play better in the 5-2 fit than in nt or that play better in nt than the 5-3 fit... even a 5-4 fit often can make 3nt just as easily as languish in 3 h/s making 3. So these considerations largely cancel each other out, in my opinion. It's more important to maximise the chance of an extra trick from right siding the contract -- in nt or with transfers -- and the negative inference of "no 15-16 bal" in major openings is invaluable. When several methods appear playable, the best way to decide between them is to add together the positive implications and the clear negative inferences about what pard SHOULDN'T have. Most of the good treatments do double duty in this way (4th suit forcing, cue-bidding up the line, etc.)

A bad 17 count is treated like a 16 count. 1m - 2nt being 17+ to 19. A lot of people don't like to languish in 1 minor when they could hav found som way to bid nt, but this is not a problem to me... when pard is wk i am happy to squeak out any old small plus if i can.

I strongly dislike opening two nt with as little as 19 -- and even dislike opening it with 20-21, but at least here there is a fair amount of "field protection" for a somewhat wonky bid. I suppose when the majority shift to 19-20 or some such, i will feel forced to shift down too, and just hate the bid 30 percent more often.

I think the above method is pretty good, even if one is not playing 2/1 style, but if one is, one shld note that 1M - 1nt(f) - 2c/d is not very encouraging at all (12 to ?) so a lot of games would be missed with 16 opposite 9 or so.

[mtvesuvius]

I upgrade liberally, so with 15-16 and a 5cM, definitely 1N. With 14, if it's a good suit then 1N, otherwise 1M. With 17, usually 1M.

[bluecalm]

My feeling is that opening 1M is better, especially at matchpoints but you for sure need some system and a lot of discussion to make it work.
Many decent bidders (Meckwell for example) just open 1NT almost every time they are in range so it can't be that terrible though
Best Italian pairs open 1M but they have gazilli in place which come in handy when it comes to solving problems of 15-17 hands.