Reverses vs. jump shifts

[Antrax]

First of all, some auctions to ensure I have the terminology correctly:

1♦-1♥, 2♠ = jump shift

1♦-1NT, 2♠ = reverse

1♦-1NT, 3♣ = jump shift

 

i.e. are jump shifts when you show a new suit unnecessarily high, and reverses when you show a new suit when responder already denied holding four cards in it?

 

And the important question, why make the distinction? With both responder can only give preferences at the 3-level, won't that mean opener needs the same amount of strength to make either? Which one is stronger, by how much, and why?

 

Thanks.

[Cascade]

First of all, some auctions to ensure I have the terminology correctly:

1♦-1♥, 2♠ = jump shift

1♦-1NT, 2♠ = reverse

1♦-1NT, 3♣ = jump shift

 

i.e. are jump shifts when you show a new suit unnecessarily high, and reverses when you show a new suit when responder already denied holding four cards in it?

 

And the important question, why make the distinction? With both responder can only give preferences at the 3-level, won't that mean opener needs the same amount of strength to make either? Which one is stronger, by how much, and why?

 

Thanks.

 

No.

 

A jump shift is a jump and a shift into another suit.

 

A reverse is a simple bid in a higher ranking suit at the two level. It does not have to be in a suit that partner has denied e.g. 1♣ 1♠; 2♥ is a reverse and partner could easily have four hearts in a hand with five or more spades.

 

A jump shift is normally forcing to game.

 

A reverse is normally forcing for one round. Some reverses are forcing to game e.g. when partner has responded at the two-level (even in a non 2/1 GF system) 1♥ 2♣; 2♠ is a reverse and it is forcing to game.

 

In a jump shift auction there is always the option to bid the suit at a lower level so the jump in unnecessary except to show the extra values. In a reverse auction we are bidding a suit at the lowest level possible given the previous auction.

 

While preferences can be given at the three level in both auctions, responder's suit is not available at the two-level after a jump shift but is after a reverse. Similarly 2NT is always available after a reverse (although many play this as a forcing convention) but often not after a jump shift.

[Quantumcat]

A reverse is a rebid that is higher than the same level in your first suit. The reason reverses have to show extra values, is that if partner is very weak, and prefers your first suit, he has to bid it at a higher level.

 

e.g.

1♦ - 1♠

2♣ - 2♦

 

If partner is weak (5-9 HCP) he can go back to ("give preference to") opener's first suit at the same level the second one was bid at. With 12 HCP in the opening, and about 6 in the response, the pair are reasonably safe at the 2-level with a minimum of 18 HCP total in a fit.

 

BUT

 

1♦ - 1♠

2♥ - 3♦

 

Because 2♥ is higher than 2♦, if partner prefers the first suit, he has to give preference at a higher level than the second suit was bid at.

 

To make a reverse, you have to have enough values to be safe at the three level when partner has 6-9 HCP. This is usually agreed to be about 16 HCP. This gives you 22 HCP total if partner has a minimum (6 HCP).

 

Now, if you have two suits in which the higher-ranking is longer, you will naturally not be making a reverse when you bid your second suit. It is a common agreement that responder is allowed to pass the second non-reverse suit if they have a very bad hand and a fit with the second suit. However, if you are holding 19 HCP or so, you don't want your partner to pass, because you know you can make game opposite 6 HCP. This is the time that you make a jump-shift, which forces your partner to game, however weak they are. Now you can bid slowly and naturally to continue the search for a fit without fear of being dropped below game.

 

e.g.

1♥ - 1♠

3♣

Opener has about 19 HCP or the equivalent and still wants to be in game even if responder is very bad. Whatever bids are made from now on are forcing even if they are not jumps, until a game-level contract is bid.

[helene_t]

If opener bids a new suit at the 3-level without a jump:

1♥-2♦

3♣

it is sometimes referred to as a "high reverse". If you consider this a reverse then the definition of a reverse becomes "a new suit without a jump, which bypasses the 2-level if the opening suit".

 

Regardless of what you call it, it is forcing to game. So if 2♦ is not a game force, it shows extras. Even if 2♦ is a game force, most play it as showing extras.

[quiddity]

And the important question, why make the distinction? With both responder can only give preferences at the 3-level, won't that mean opener needs the same amount of strength to make either? Which one is stronger, by how much, and why?

 

Thanks.

 

A jump shift is stronger because, by definition, opener is jumping past responder's simple suit rebid. There is less room to stop in a partial.

 

1♣ 1♠

2♥

 

This is a reverse. Responder can make a simple rebid of 2♠ to show extra length with unknown strength and later bid 3♠ to show a minimum - there is room here to stop in a partial.

 

1♣ 1♥

2♠

 

This is a jump shift. Responder has to bid 3♥ with extra length and there is no room to stop in a partial. Opener can't pass because responder is still unlimited. This is game forcing.

 

edit: just realized Cascade said the same thing at the bottom of his post. Way to bury the lead! :P

[Quantumcat]

quiddity - an excellent explanation of why a jump shift has to be gameforcing! Thanks.

[ggwhiz]

The old but not THAT long ago standard was that the jump shift and reverse showed the same strength and that is often what is initially taught.

 

As so well explained, the jump shift is now considered to be a game force, may be based on extreme distribution and doesn't promise to make every game but you want to be there.

 

I think it's an improvement but relatively new in standard thinking (10 years?).

 

In your first example, (1d-1h-2s) I actually play that as a reverse, not game forcing. To do that, you need a tricky tool (Ingberman) to stop in partscore which is basically lebensohl.

 

A 2nt bid now requests partner bid 3c after which any simple bid (like 3h) is meant to play. ie. a direct 3d bid is game forcing but if you bid 2nt and pard then bids 3c, your 3d bid is to play.

[Quantumcat]

The old but not THAT long ago standard was that the jump shift and reverse showed the same strength and that is often what is initially taught.

 

As so well explained, the jump shift is now considered to be a game force, may be based on extreme distribution and doesn't promise to make every game but you want to be there.

 

Yeah almost all the time, if your partner has mustered up a response to your one-level opening, then his default action after you bid your second non-reverse suit is to give simple preference. So if you have less than game-forcing values you are unlikely to miss game by not making a jump-shift.