Stephen Tu, on 2019-April-05, 18:52, said:
Vast majority of strong players gave up on using 1M-3M as strong and forcing a long time ago. They did the same for Swiss raises. The problem is just that these bids are too high. There's not enough room to exchange enough information below 4M to make an accurate assessment of slam potential. Ideally you want at least one hand to be able to show both distribution and high card range generally. The better response structures to the 2nt raise do that, and can also conceal if both opener and responder are minimum. (Typical: 3c = min range, responder with min GF can just sign off at 4M, but bid 3d to enquire further).
3M as F raise isn't quite as bad as Swiss since it's several steps lower, but given that 2nt can reasonably handle the entire range of forcing raise hands, you don't really need to also have 3M as forcing; it's more useful to have 1M-3M available as some sort of preempt/mixed raise or some such.
The pattaya web site argument in favor of Swiss (reserving Jacoby for stronger hands only) for me is logically weak. They claim is that it is better for weaker responders (min GF) to Swiss. This is wrong IMO because there isn't room for opener to show shortness. Even if responder has min GF hand opener needs a way to say "if your values aren't in my short suit, we should be in slam". Can't do that with only a couple bids left. They claim that it's a problem that opener doesn't know how strong responder is and responder should not take captaincy. It's really not a problem. Responder with non-fitting minimums will simply sign off frequently and stop cue bidding. Opener can simply assume that responder who stops cooperating is on the minimum end. Even in the std inefficient Jacoby structure one can do things like use 3M or 3nt as waiting bids to differentiate stronger from weaker holdings.
So experts generally use a combo of splinter raises (sometimes with multiple ranges, or perhaps distinguishing between singletons/voids, or maybe both), and 2nt sequences to cover their raises, with a few hands with a good side suit choosing to go through 2/1 (or perhaps relay sequence starting with 2c if available).
What you say is interesting but I'm trying to put the 2NT Jacoby in my system without changing much the structure is therefore keeping 1M-3M forcing (with range 14-18 and balanced hands) in this way still partly and using 2NT for the remaining unbalanced hands. The indication of the site of Pattaya Bridge is made to widen the "turn of horizon" presenting other declarative eventualities and for the examples of hands. The answers to the 2NT Jacoby are therefore: 3x is shortness in unbalanced minimum hand, 4M minimum hand without slam vision, 3M undefined shortness in good maximum hand and 3NT idem w / o shortness trying to avoid, by balancing all this, to complicate a system that I tend to keep it as natural as possible.