[Cyberyeti]

In the context of a different system, we play our jump shifts as GF, either the old fashioned one suited rock crusher or an opening hand+ with a good 5+ card suit (2/top 3) and decent (Q or better) 4+ card support for opener. It's assumed to be the fit unless you repeat your suit or rebid 3N.

This has proved very useful for slam bidding.

[CSGibson]

I have played strong jump shifts, weak jump shifts, and other treatments for jump shifts.

There has never been a hand where I've picked it up, and after partner opened, said "Damn, I wish I played weak jump shifts, now I have no way to bid this hand". The bid doesn't really solve a problem, so I think it's the least useful treatment.

Strong jump shifts are very useful, however, especially if you strictly define how you use them. If you play strong jump shifts, you should stretch to use them on hands where you have a good 5 card suit and support for partner, or your own single-suit that does not need support from partner. You have laid your slam potential on the table early, and can let partner make further decisions (assuming you have some sort of minimum, which most of my jump shifts are). They are very good for making good slam decisions, and sometimes for forcing at a low level (just picture a hand like AKQTxx Ax QJx xx, & the bidding 1D-1S, 2C to you. Exploring slam is problematic at best, maybe requiring a 4th suit forcing call, & leaving some ambiguity as to whether you are trying to show extra values, or just find the best strain to play in. Now picture an immediate 2S over 1D as slam interest, 5+ spades. This seems to be a much easier auction to explore slam possibilities)

Other jump shifts (Bergen raises, fit jumps, intermediate jumps, etc) can also be useful when they come up, as they can also be used to solve bidding problems. I suggest discussing with your partner what fits best with your system and style of play.

[awm]

Another possibility that hasn't been brought up is invitational jump shifts (IJS).

This solves a bunch of problems. First, when you bid 1m-Pass-2M and partner has a bad hand, you get out one level lower than you would without the IJS. This is really big when partner happens to have singleton in your suit as well! Second, you get some of the same benefits of strong jumps because 1m-1M-??-3M becomes forcing. So you can show your strong one-suited hand without having to go through fourth suit forcing. Third, it helps when opener has extras because this invite is sort of a "tweener" hand where it can be very difficult to figure out whether to push for slam. For example, say the auction goes 1♥-1♠-3♦-3♠-4♠ and you have to decide whether to bid on. You have about 19 opposite about 10 which might be a slam but often will not be, and you're already at the four-level just finding your fit. Again, invitational jumps gets you 1♥-2♠ and partner knows a lot about your hand and can look for slam if he wants to (I recommend playing 2NT as shortness ask and a game-going hand in this auction). Fourth, it's consistent with the popular 2/1 way to play jumps to the three-level (i.e. 1♦-3♣ and now for many people 1M-3m) so you don't have to remember something about one meaning at the two-level and a different one at three.

[Vampyr]

awm, on 2012-January-12, 19:45, said:

Another possibility that hasn't been brought up is invitational jump shifts (IJS).

Except in posts 5, 15 and 19.

[awm]

Vampyr, on 2012-January-12, 20:16, said:

Except in posts 5, 15 and 19.

But none of these were really recommending playing them (in fact #5 was just asking for a definition, to which he was quickly told there was none!), and at least one was more angled toward the three-level jumps.

[gwnn]

awm, on 2012-January-12, 21:15, said:

But none of these were really recommending playing them (in fact #5 was just asking for a definition, to which he was quickly told there was none!), and at least one was more angled toward the three-level jumps.

There's no harm in admitting you were wrong for once. Your post was valuable anyway.

[the hog]

gwnn, on 2012-January-10, 10:36, said:

1♣-p-2♦ is a good auction for a SJS. The rest are not as good.

Well this is wrong as well. The truth is the type of jump shift you play should of course fit in with the rest of your system. Anyway to say the rest are not as good is a silly comment.

[gwnn]

the hog, on 2012-January-13, 04:19, said:

Well this is wrong as well. The truth is the type of jump shift you play should of course fit in with the rest of your system. Anyway to say the rest are not as good is a silly comment.

Fair enough. My comment was wrong, let me try to rephrase it

"In a natural system, with not so many gadgets, 1♣-p-2♦ is a good auction for a SJS. Other jumps are also playable as strong jump shifts but the most benefits, in my opinion, come with the SJS auctions after 1♣-p-2♦."

[Zelandakh]

awm, on 2012-January-12, 21:15, said:

But none of these were really recommending playing them (in fact #5 was just asking for a definition, to which he was quickly told there was none!), and at least one was more angled toward the three-level jumps.

My post (#8) recommends playing either WJS or IJS while still giving some of the major alternatives available.

[Vampyr]

Zelandakh, on 2012-January-13, 06:07, said:

My post (#8) recommends playing either WJS or IJS while still giving some of the major alternatives available.

Mine (#19) recommends playing IJS when playing 2/1 always GF.

[akwoo]

Another alternative, especially playing 2/1 and especially at IMPs (where bidding thin games is more important and opponents slightly less likely to intervene with mediocre hands), is fit showing jumps.

Over a major, they should show 4+ support for partner, 9+ cards in trumps + suit bid, 9-11 hcp (not counting quacks in short suits). (You might want to require 10 hcp with 5422 and 9 with 5431, or require 10-12 if you open aggressively.)

Partner can bid game with a minimum if you have a double fit.