thepossum, on 2018-October-30, 22:28, said:
I didn't say it wasn't forcing.
Well, you actually did, but I'm guessing now it was more of a typo and you meant to say 'non-game-forcing', which changes things a little
Going back to your example, suppose you hold AQJxx-x-Kxx-Jxxx, and the auction goes 1
♦ - 1
♠ - 1NT.
You now need to know two things - whether partner is minimum (want to play a partscore, not game), and whether partner has three spades (want to play spades, not no trumps). 2
♣, new minor forcing, gives you precisely the answers to these two questions. You will know immediately what the final contract should be.
Give yourself an extra spade:
AQJxxx-x-Kxx-Jxx
Now you know you want to play in spades, and need to know whether it should be in game or not. Bid 3
♠, telling partner to pass with a minimum or bid game otherwise.
Make your original hand a little stronger:
AQJxx-x-Kxx-Axxx
Opposite a 1NT rebid, you know you want to play game and not slam, but don't know whether it should be spades or no trumps. Again, after new minor forcing, you will know exactly the right contract.
With these hands, perhaps opener will bid something other than 1NT. Now you can use other sequences to continue in different ways.
If you decide to jump shift instead, you'll quickly find yourself stuck - you don't know whether opener has a minimum, medium, or maximum hand; opener doesn't know whether you have 13 points or something much stronger; and neither of you know what suit you want to play it. You can communicate some of this information, but not all of it in time.
That's why Soloway jump shifts are restricted to certain hand types (and have nothing to do with points - that's just GIBberish - there are plenty of 20 point hands you shouldn't jump shift with, and some weaker ones you should) - ones where the information you need to know can be communicated in time.
The main point is that standard bidding covers most sequences pretty well - not every single one, but again, each time you come up with a hand you think the system doesn't handle well, send it through and you may find there is actually a good solution. (Not necessarily one that works with GIB though
)
In fact, I don't recall the last time I made a strong jump shift. If you're getting started with 2/1, I'd suggest not using them at all - once you're more familiar with how all of the alternate options works, you'll start to learn if/when they're needed. (Most people on BBO would assume a jump shift is weak too.)