[Hawkster1]

I seem frequently to encounter partners who give a jump shift response to my opening of 1 in a suit. E.G: 1-♣,pass, 2-♥ or ♠; 1-♦, pass, 2-♥ or ♠; 1-♥, pass, 2-♠; etc.
Frequently the responder will have 6 cards in his or her bid suit, a few points, but not much else.
What is the rationale for this response? It seems almost never to be helpful. It used to be that a jump shift would indicate a VERY GOOD hand; and the theory was that one gives up a round of bidding to make subsequent bidding easier. However, I see no theoretical basis for a jump shift with essentially a trash hand and six cards in the suit. Can someone who uses this response, as I have described it, explain why you think it is helpful? I understand that it makes a bid more difficult for the opponent who has not yet bid -- but this seems of little benefit for all of the problems that the jump shift otherwise creates.

[P_Marlowe]

 Hawkster1, on 2016-May-29, 07:35, said:

I seem frequently to encounter partners who give a jump shift response to my opening of 1 in a suit. E.G: 1-♣,pass, 2-♥ or ♠; 1-♦, pass, 2-♥ or ♠; 1-♥, pass, 2-♠; etc.
Frequently the responder will have 6 cards in his or her bid suit, a few points, but not much else.
What is the rationale for this response? It seems almost never to be helpful. It used to be that a jump shift would indicate a VERY GOOD hand; and the theory was that one gives up a round of bidding to make subsequent bidding easier. However, I see no theoretical basis for a jump shift with essentially a trash hand and six cards in the suit. Can someone who uses this response, as I have described it, explain why you think it is helpful? I understand that it makes a bid more difficult for the opponent who has not yet bid -- but this seems of little benefit for all of the problems that the jump shift otherwise creates.

There are two styles playing WJs (weak jump shifts)
a) trash hand, say 4-7 HCP (or weaker) with a 6 carder
b) constr. hand 6-9 with a 6 carder

Playing b) you get more room to explore the best game, if responder rebids his major with 2M,
showing 6+, e.g

1C - 1H
2C - 2H

In the context of WJS, the 2H is now forcing, it shows an inv.+ hand, a jump rebid of 3H showes
the SJS, showes SI and sets trumps.

Playing a) has lesser impact on the system, has some preemptive effect on the opponents and
lets you stop in 2M, if opener is strong, but has only a single in partners suit.

This is not all, but hopefully you see some points with some merrits.

As long as they are used in a disciplined way they work, if you can handle the memory impact a)
is better, we play b), but be prepared to play 3M some of the time in the beginning, when slam is
lay down.
You can also use the jump to 2M as showing 54 major hands with less than inv. streng, see
Reverse Flannery.

With kind regards
Marlowe

PS: I like SJS, but since I need a partner, ..., I have other preferences, that are stronger priority
to me.

[Stephen Tu]

 Hawkster1, on 2016-May-29, 07:35, said:

[partners use weak jump shifts]
What is the rationale for this response? It seems almost never to be helpful. It used to be that a jump shift would indicate a VERY GOOD hand; and the theory was that one gives up a round of bidding to make subsequent bidding easier. However, I see no theoretical basis for a jump shift with essentially a trash hand and six cards in the suit. Can someone who uses this response, as I have described it, explain why you think it is helpful? I understand that it makes a bid more difficult for the opponent who has not yet bid -- but this seems of little benefit for all of the problems that the jump shift otherwise creates.

A weak jump shift shouldn't really create too many problems for your side when it comes up. The hand is tightly defined and you basically know what to do, most often pass, bid game in the major when appropriate, compete to 3 level over opponent's call when appropriate. You are likely getting to the same place if partner didn't jump, as on most sequences partner would have bid 1 then 2 if the WJS wasn't available. You have the benefit of obstructing 4th hand, and also stop opener from jump rebidding the opening suit or reversing on a misfit when they know responder is weak and game is remote, and get to play in a lower partial in the weaker hand's long suit instead, which is normally a good thing.

You should be aware that there are different ranges of WJS in use. In Europe a range of ~5-8 is more popular as far as I know. This range is more common and removes a class of hands from your 1 level responses so creates useful negative inferences (so that one can rebid the major as invitational on various auctions, for example, and stay at the 2 level on a misfit, rather than having to be forced to the 3 level to show an invite, and jump rebidding the major can be forcing, which can somewhat substitute for the strong jump shift). Americans for whatever reason seem mostly to use a ~0-5 range, ultra-weak, to allow a response on super weak hands. I personally don't care so much for the really weak range.

The drawback of the weak jump shift is the loss of the strong option, or other possible uses (invitational jump shifts, responder's reverse flannery, handling invitational NT responses, some ranges of minor raises).

[kenberg]

I play weak jump shifts with some, strong jump shifts with others.

It has an impact on other agreements.

For example: 1C-1H-2NT. Suppose you play weak jump shifts. Then responder cannot have a weak hand with six hearts, such as KJxxxx and out. With that hand he already bid 2H at his first turn. Now maybe you think if that is all he had he should have passed 1C but with short clubs and six hearts that could be very wrong. So, if that hand is bid 1C-2H, then after 1C-1H-2NT responder will either not have six hearts or responder with six hearts will have the values to make 4H a reasonable contract. This can simplify what happens next. If you are not playing weak jump shifts then you will occasionally need a way to get out in 3H after the 2NT rebid. Wolff sign offs maybe. Whatever. Or just hope for the best.

There is a lot to be said for strong jump shifts, especially if there has been enough discussion to use them well. But weak jump shifts have their uses. I am comfortable with either.

[wank]

 Hawkster1, on 2016-May-29, 07:35, said:

I seem frequently to encounter partners who give a jump shift response to my opening of 1 in a suit. E.G: 1-♣,pass, 2-♥ or ♠; 1-♦, pass, 2-♥ or ♠; 1-♥, pass, 2-♠; etc.
Frequently the responder will have 6 cards in his or her bid suit, a few points, but not much else.
What is the rationale for this response? It seems almost never to be helpful. It used to be that a jump shift would indicate a VERY GOOD hand; and the theory was that one gives up a round of bidding to make subsequent bidding easier. However, I see no theoretical basis for a jump shift with essentially a trash hand and six cards in the suit. Can someone who uses this response, as I have described it, explain why you think it is helpful? I understand that it makes a bid more difficult for the opponent who has not yet bid -- but this seems of little benefit for all of the problems that the jump shift otherwise creates.

it's used for a weak hand with a long suit, and no support for opener and no unbid majors, perforce it's very likely that that suit should be trumps. as this suit is expected to be trumps and the range is pretty tightly defined, the loss of a level isn't important for the bidding side, but has a significant pre-emptive effect on the 4th player. it also makes the auction much cleaner when opener has extras and would jump himself - the weak responding hand is able to show its long suit immediately, before being pre-empted by opener. for example, if responder has a 6 count with 6 hearts and it goes 1c-1h-3c, he'll most likely have to pass, but 4H can be cold. the same doesn't apply in reverse, because after 1C-2H, a strong opening hand can still bid on safely (without needing to jump, because minimal openers would all just pass).

the alternative [one of the alternatives] strong jump shift has fallen out of favour because it's so rare. it's very unusual amongst tournament level players to keep this weapon in the armoury, because other methods such as weak jump shifts, are useful for reasons of frequency. still, there is nothing wrong with strong jump shifts and they're great when they come up.

[1eyedjack]

One of the reasons for the move away from strong jump shifts was that strong type was (rightly) so narrowly defined that a simple change of suit could still contain a variety of GF hand types. Given that a simple change of suit could conceal a GF hand anyway, and you needed the mechanism later to clarify that point, then armed with that or similar mechanism it is not a huge leap to make the necessary adjustments to that mechanism in order to cope with the added possible burden of responder holding a classic Soloway jump shift. Furthermore, opener's rebid following a simple change of suit is often very revealing to responder, and some of those rebids are no longer available if you have made the strong jump.

That said, if you have a hand that fits a strong jump shift, you are probably better placed in the auction if you happen to have strong jump shift responses available, unless you have really well honed follow-ups following a simple change of suit. But those hands are rather infrequent.

However you define your jump shift response, provided that the definition is sufficiently narrow, you are going to be ahead of the competition when those hands come up to fit your prearranged method.

Again, that said, I am not a huge fan of weak jump shifts or of strong jump shifts.

Partner opens 1D and you have a 4-6-2-1 shape and are in range for a weak jump shift. Are you going to bid 2H and bury the Spade suit, or bid 1H and risk not being able to rebid your Hearts without showing some sort of range outside of the weak jump shift range (from having failed to make the jump shift)?

[P_Marlowe]

 wank, on 2016-May-29, 08:56, said:

<snip>
the alternative [one of the alternatives] strong jump shift has fallen out of favour because it's so rare. it's very unusual amongst tournament level players to keep this weapon in the armoury, because other methods such as weak jump shifts, are useful for reasons of frequency. still, there is nothing wrong with strong jump shifts and they're great when they come up.

While I agree, that the main argument against SJS is freq., depending on the kind of WJS you play,
espesially the trash variant, the freq. of SJS (Soloway style) is similar, and may even be higher.