[Tim Ocean]

Which version of 2/1 do you prefer? The one where 2/1 is absolutely GF or where it may not be GF when you rebid your suit? Does one have some subtantial advantages or drawbacks over another?

[DavidKok]

I prefer that a 2/1 is 100% GF, including 1♦-2♣. The differences between 2/1 GF and "2/1 99% GF" aren't that big, since it's just a few specific auctions that you are reallocating. The 99% version is slightly more vulnerable to interference, since you now don't know to what level you are in a force. I also don't see a strong need to have the escape, if you really wish to have a way to stop at the 3-level with a hand with a rebiddable suit and approximately 9-11 HCP you can reserve the direct jump shift for this purpose (an intermediate jump shift), though starting with 1NT (forcing or semiforcing) often works as well if not better.

[P_Marlowe]

I dont really care, if I have agreed to one, I play it, but in my serious partnership I play 100% GF, except for the seq. 1♦ - 2♣.
To do this we we play intermediate jump shifts, obviously if you like conventions like Bergen, you cannot do this.
This is in the context of a weak NT system and a semiforcing NT response to a major suit opening.

The differences are small, basically you need to force to game with only inv. values, which is ok, as long as your opening standard is not
too crappy (*), meaning that you end up in hopeless contracts, due to the stretching, but the freq. matters more than a single disaster.

(*) If your openings get too crappy / wide ranging, this tends to generate its own set of issues independ of the 2/1 style you decided to adopt,
which may work out for you anyway, again freq. matters more than single disasters.

[mw64ahw]

For me it depends on how light you can open and what you need to bid at the two-level. I prefer a lighter style so won't constrain myself with having to bid game when that's the fashion.

[mikeh]

I play 100% gf

I also play 1D 3C as invitational with a good 6+ club suit, which takes the strain off of 1D 2C.

In my main partnership I play 1C 3D as the same….natural with 6+ good diamonds (always a 1 loser suit at worst to allow opener to bid 3N with say Kx in diamonds and a balanced hand with scattered values)

Also, in my second partnership, 1S 3D shows 6+ hearts and invitational values (3H is a 4 card spade limit raise)

But these invitational bids rarely arise.

Btw, I do NOT at all agree that this means that one has to overbid to bad games when opener is light. I play a style in which we open 99% of all 11 counts and many 10 counts. The result is that we respond to 1M with 1N with as much as a misfitting, no great suit, 13 count and go from there. We play a complex bart structure over that, which allows us to describe a lot of hand types.

Meanwhile, we have the benefit of pure 2/1, in that both partners know before opener’s second bid that we’re going to game.

As david noted, the difference between the two approaches is not huge….

But…and this, though rare, is often important when it arises….when one has a GOOD hand and suit and respond 2/1, slam bidding is made easier by being able to rebid the suit without fear of being passed.

After say 1S 2C 2H, being able to bid 3C forcing on say Kx Ax xxx AKQxxx is nice. Wtf do you bid playing 3C as non forcing, assuming you don’t play strong jumpshifts? I’ve played SJS and I’m very happy too longer to do so.

As always, my opinions are based on a style tailored to imp play where slam bidding is far more important than it is at mps….it’s an issue of frequency of gain over size of gain.

[mw64ahw]

Not a huge difference between the approaches especially if you have an artificial approach after the 2-level bid. I use a variation of the following over 1M-2♣ Advancing a Nebulous 2C response which aids slam bidding
A benefit I see of not using a GF approach is that it frees up 2NT to show 55 in the other suits if you have a misfit and are looking for a better part-score where the weaker hand can make tricks, so for example
1♠-1NT
2♦ -2NT can show 1525 (invitational if you want)
likewise
1♠-1NT
2♥-2NT can be 1255 or 126+x (weak)
with
1♠-1NT
2♥-3♦ being invitational

[blackshoe]

Playing Precision, so 1♣ is out of the picture here.

1M-2/1 is 100% GF. Opener's 2M rebid shows six or more trumps; 2NT is a catch-all.
1♦-2♣ is invitational or better; invitational is shown by rebidding 3♣.
1♦-2♦ is invitational or better; invitational is shown by rebidding 3♦ or 3♣.

Basically the structure of Santa Fe Precision.