[golbat]

I play regularly with a number of different partners: half SA, half 2/1. I am comfortable in both systems, and recognize that some bidding situations favor SA while others favor 2/1. But I cannot seem to find a detailed, point-by-point discussion of this among the experts or even among good players I know.

What I find instead is this: the SA players acknowledge value in both systems but are reluctant to change as they are happy with what they know ... and the 2/1 players, unfortunately, are dismissive or worse and typically refuse to even entertain the question.

P.S. EDITED to say Thank You to everyone who has responded so far and to clarify that when I say SA vs 2/1 I mean strictly that: a 2/1 response means GF not just 10+, and 1M/1N is forcing, irrespective of conventions like inv. minor, NMF, 4SGF, Bergen, Drury, DONT (et al), Michaels, U2N, RKC, cuebid, and the rest. I did not realize that some players associate SA with "plays very few conventions" and 2/1 with "plays lots of 'em."

As mentioned, I play both SA and 2/1 but will acknowledge a preference for the former, as on the whole I find it provides more flexibility to describe intermediate hands, AKA, "Sometimes your best contract is 2N." I also, as mentioned, have been turned off by the dismissive attitude of more than a few 2/1 players - typically those who never learned SA - and find myself mumbling "Good grief, sometimes this sounds like a cult."

[akwoo]

golbat, on 2022-January-12, 18:48, said:

I play regularly with a number of different partners: half SA, half 2/1. I am comfortable in both systems, and recognize that some bidding situations favor SA while others favor 2/1. But I cannot seem to find a detailed, point-by-point discussion of this among the experts or even among good players I know.

What I find instead is this: the SA players acknowledge value in both systems but are reluctant to change as they are happy with what they know ... and the 2/1 players, unfortunately, are dismissive or worse and typically refuse to even entertain the question.

I generally refuse to play SA instead of 2/1 with strangers, but that's not because I think 2/1 is a lot better. What is true is that 2/1 is a lot better than SA with none of NMF, Lebensohl, 4th suit forcing, and Jacoby 2N (or various variants of these conventions). When someone plays 2/1, I can be fairly sure they play all these conventions as well. When someone doesn't play 2/1, they frequently don't play any of these conventions, nor do they play any substitute for these conventions. Then you have end up having no way of finding 5-3 fits, getting killed when opps interfere over your 1N opening, missing distributional slams, and so on.

Switching to 1N forcing and 2/1 game forcing is really the last of this series of conventions to learn, and the one with the most downside and least upside.

[DavidKok]

I think 2/1 is a significant step up from SA, regardless of other conventions. That being said, both systems have their weaknesses, and both benefit significantly from adding the conventions akwoo mentioned (and there's a few more I'm also in favour of adding).

The benefit of 2/1 is that you reduce the need to jump to show strength on 2/1 auctions. This is a big aid when you are faced with choice of game decisions, or with game versus slam decisions. By making an auction game forcing at a relatively low level both partners are free to describe their shape, and later their values, without fear of being dropped in a partscore. This is also one of the benefits of some forcing club systems, being able to establish game forces at the 1-level. 2/1 does that, but slightly worse (at the 2-level). In one smooth motion this also introduces the principle of fast arrival.

There are downsides to this, though. Having a forcing or semi-forcing 1NT is a loss compared to having a NF 1NT. Vanilla 2/1 has no way to give a direct 3-card limit raise in a major suit, which I personally think is a big downside (and I play some artificiality to reclaim this option) - proponents of 2/1 will sometimes say that 1NT semiforcing into 3M is fine, because if you get passed in 1NT you might belong there anyway, but I don't think it's a winner on balance. Also showing invitational strength shapely hands is difficult, which is why a lot of players have taken to playing 1M-3m as ~9-11 natural NF (and you still need a solution to show hearts when partner opens spades).

2/1 loses some accuracy on partscore hands, by collapsing a wide range of hands into 1NT, or jumping on some weaker hands. At MPs this can add up to make a noteworthy cost, although I still think it's a good system on balance. At IMPs losing some percentages on partscore auctions is not a big deal, since you gain lots of resolution on game-going and slam-going hands. 2/1 is a very natural fit to IMP scoring because of its emphasis on reserving bidding space for strong hands.

[awm]

A few comments here:

1. When playing SA, it's important to have good agreements about which sequences show (and deny) extras in 2/1 auctions, what's forcing, etc. For a pickup partnership this may be too much discussion (which is why I prefer 2/1 in short-term partnerships). However, having this discussion will help your results even if you play 2/1 GF (so in some sense, forcing the discussion can be an advantage for SA).
2. Assuming comparable skill level, discussion, experience... 2/1 will be better in auctions that start with a 2/1 GF bid and worse in auctions that don't. This is pretty obvious given that the 2/1 GF bids are better defined and the 1NT response is worse defined. This gives some advantage to 2/1 at IMP scoring (usually better slam bidding) but SA will often reach better partials and can also handle responder's invitational hands better (some advantage at MP scoring).
3. If you adopt an aggressive opening style, then 2/1 will either get you overboard (open on 10, game force on a non-fitting 12, oops) or the advantageous 2/1 auctions will become a lot less frequent (open on 10, but now you need 14+ to GF instead of 12+) which makes SA a better fit for such an opening style.
4. The conventions that you want to tack on to the system are probably a little different -- for example, single-suited invites are handled really well in SA and can be a huge problem in 2/1, so it makes sense in 2/1 to play 1M-3m as natural invitational, but you would never want to do this in SA.

[DavidKok]

Point 3 doesn't seem accurate to me. If you decide to open aggressively, you have to decide whether responder can force to game on a classical opening hand regardless of what system you play. Also, in my personal experience, the 'oops' scenario wins more often than it loses. Sharp games have a tendency to come home anyway.

I definitely prefer a "we might not make game, but we sure will bid it!" agreement in 2/1 over "you need 14 HCP to bid 2/1". But this is a cost of my opening style, not of the GF nature of the 2-bids. We'd have the same issue in a standard system.

[pescetom]

DavidKok, on 2022-January-13, 05:25, said:

Point 3 doesn't seem accurate to me. If you decide to open aggressively, you have to decide whether responder can force to game on a classical opening hand regardless of what system you play. Also, in my personal experience, the 'oops' scenario wins more often than it loses. Sharp games have a tendency to come home anyway.

I definitely prefer a "we might not make game, but we sure will bid it!" agreement in 2/1 over "you need 14 HCP to bid 2/1". But this is a cost of my opening style, not of the GF nature of the 2-bids. We'd have the same issue in a standard system.

It seems to me that (like mikeh) you are effectively saying that your declarer play is better than most opponent's defence
Kudos to you, but it can't be true for the majority.

I'm also a bit dubious about point 4. I fully agree with awm "it makes sense in 2/1 to play 1M-3m as natural invitational", but I never saw much downside in that. I take your point about hearts after spades however.

[mycroft]

12-opposite-12 maybe is only 45% to make, but we don't always get perfect defence.

If we open on 11, and partner forces to game with 12+, *usually* it won't be 12. And 11-opposite-13 is still "putting the defence to the test". And Defence Is Hard.

If we force to game on 12, *usually* partner doesn't have 11.

The times it's wrong - well, sometimes we get away with it. Sometimes -50 or -100 is actually a good score. At IMPs, in particular, 40% games come in 40% of the time.

I agree with most. It's not that SA is bad and 2/1 is good (I played a K/S-branded system with 1NT NF seriously for 5 years, and didn't miss 2/1 GF much. Not sure I would now, but it's just that I've forgotten the continuations). It's that SA *or* 2/1 is a system full of holes that are covered (more or less) by a bunch of gadgets (invm, some GF major raise, negative doubles, some decent NT system (including defence to defence that isn't Stolen Bid Doubles), NMF, 4SF,...) And even when I was learning in 1980s, "you can count on a 2/1 player to play them. You can't count on a SA player to."

And the crutches that make wide-range 1-openings work are more damaging if they're not there than 1♥-2♣ potentially being on a 10-count.

[DavidKok]

pescetom, on 2022-January-13, 16:47, said:

It seems to me that (like mikeh) you are effectively saying that your declarer play is better than most opponent's defence
Kudos to you, but it can't be true for the majority.

I think it's more about the value of information, rather than flattering declarer play. Mycroft already gave most of the answer - I am happy to bid all 40% games and see which ones make and which ones don't, and you will not frequently have a disaster, just occasionally. But more importantly, if you have a shapely not-quite-an-opening, opening it anyway is a much more descriptive call than passing (after all, you could pass with almost anything!). Being a point or two short is a flaw of the bid, but it protects partner if the bidding gets competitive (since they have a much better read on your hand) and puts pressure on the opponents. I think those upsides are sufficiently big that I'm willing to get to hopeless games more often than conservative openers.

As a cherry-picked example, Wednesday I held ♠Ax, ♥Kxx, ♦Txxx, ♣xxxx. My partner opened and the bidding went 1♠-(P)-1NT-(P); 2♠-(pause, followed by pass)-P-(very long pause, followed by pass). This was online so partner's hand was revealed to me on the opening lead: ♠KJ9xxx, ♥xx, ♦QJx, ♣Kx, and the opponents were cold for 4♥ (spades split 4-1, but the singleton was the ten) with 2♠ off one. Many good things can happen when you open under strength hands, as well as some bad things.

[awm]

Bidding 3NT on 22-23 hcp isn't a case of a "40% game that might make" (which I agree is perfectly respectable to bid, especially at IMPs). The double-dummy chance of making these contracts looks like:

22 hcp: ~10%
23 hcp: ~20%

Even 2NT with 22 hcp is only about ~40% to make, so opponents giving you a trick doesn't even get you to making 3NT half the time.

There are definitely advantages to opening light -- you can steal some partials or games from opponents, you can find a good sacrifice if there's a fit, you can get partner off to a better lead, etc. It might be a net positive even with the possibility of reaching a 22-23 hcp game without a fit. But you'd definitely do much better if you could open light while avoiding the 22-23 hcp non-fitting game.

[DavidKok]

Sure, and once you show me how to do that without crippling the rest of the system I'll ask my partner to play that. I think you have to include all kinds of balanced hands to get figures that low, so forgive me when I say I think it doesn't apply to the situation.

We do cater to weak openers in one small way - we have a way for responder to show 11-13 balanced NF at the 2NT level. But other than that I think trying to avoid the sharpest games is not worth the stress it imposes on the rest of the system.

[mycroft]

Yep, exactly. I don't expect I'll get to too many 11 opposite 11s, though, as good 12 is the low end of my 2/1 range (no matter what the low end of my opening range is. Okay, playing 10-15 Precision makes it higher).

I absolutely want to avoid the 23-point "hopeless" games. I also want to avoid the "your passed hand was way too good" missed games. And the "give them the first bite at the apple" auctions when I pass rather than open 1♠ with a decent 11.

One of my lines from years ago was "I don't mind playing 24-point games, if I have to to ensure I don't miss any 26-pointers. That doesn't mean I'm *looking to play* 24-point games." Still true (and more true for 23!)

Where to draw the line to get the best of all the bad options is the perennial question isn't it?

[Gilithin]

As a general rule, 2/1 trades significantly more accurate game and slam bidding when Responder has strength against a not-insignificant disadvantage when Responder has an invitational hand. There are certain hands where playing it more or less predetermines a poor result. You make up for that on close 3NT versus 4M/5m decisions and on slam hands. Experience suggests that at IMPs the upside is more important than the downside, which explains why the majority of natural bidders have moved over to some sort of 2/1 structure. At MPs I think the case is still open. It is also worth pointing out that there are various levels of 2/1 not being game-forcing, such as "GF unless 2NT/ 3♣", "forcing to 2NT" and the like and each of these have slightly different pros and cons. Similarly, 2/1 GF might include a forcing 1NT response or it might use a 14-16 1NT and a semi-forcing 1NT.

For the most part, 2/1 is relatively easy to play with a pick-up partner because it is rarer to have a mix-up on whether a particular call is forcing or not. I also tend to agree with Adam about the light opening bids. If a pair wants to put some effort into this style, they are far better off moving over to a Strong or Mixed 1m system than trying to tack it onto a standard 2/1 GF method. And if you do not want to put some effort into your system, 2/1 GF is almost certainly not optimal. You almost require certain conventions for it to be effective. With the same level of effort you can make a non-GF 2/1 system that is also very good. But it is harder to detail to a random partner agreements about which calls are forcing than about the conventions and gadgets.

So which is best? That depends entirely on the type of partnership, the level of detail you want, the style of play you prefer and the areas that you like to concentrate your efforts in. Playing both in different partnerships is a decent way of learning more about the logic of bidding system design and where the system holes are. Generally, good bidders remain so regardless of the underlying system. Learning good judgement is more important than putting yourself in a particular system tribe.