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What *is* the argument for a 2/1GF system?

#1 User is offline   Jinksy 

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Posted 2011-November-13, 16:36

I've seen a lot of assertions that it's better, but very little reasoning to show it.

I recently read Bridge in the Enigma Club by Peter Winkler, which recommends non-forcing 2/1s; he's a cryptographer rather than a world class player, but I didn't find his arguments any less persuasive than those I've heard for the reverse.

I assume it's agreed that when playing 2/1 you gain vs the alt whenever you make a 2/1 bid (except on marginal hands where you have to force to game without knowing enough about P's hand to know if your values are working), and lose whenever you bid 1N (or canape as a result of insufficient strength). Most hands presumably fit into the latter category, so presumably the argument is that the gain is sufficient to outweigh this.

But it only seems to help significantly on slam-seeking hands, which are a pretty small minority. Sure, you might bid games more accurately on occasion, but that seems rare, and is offset partially by the fact that since the defence plays a greater role in games than slam, you're also helping them when your bidding is more detailed.

I'm not against 2/1 as a GF per se - I don't really have a view. But I'd really like to hear some decent arguments either way.
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#2 User is offline   whereagles 

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Posted 2011-November-13, 16:46

2/1 GF has a slight advantage on some slam auctions. Classic 2/1 F1 has some advantages on lower level auctions.


Example of 2/1 GF advantages:

1M 2x
2y 3x <-- can get messy if responder has 12+ and 3x is not forcing.


Example of 2/1 F1 advantages:

1S 2H <-- done with 10-11 hcp.
raise

(In 2/1 GF it could go 1S-1NT-2x-2NT-pass and hearts would be lost.)


By the way, the auction

1M 2x
2M 3M

is forcing in BOTH systems. Why? Because an invitational hand with 3 card support usually bids 1M-3M in a 2/1 F1 system.
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#3 User is offline   aguahombre 

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Posted 2011-November-13, 16:48

My argument is simple. I don't know all the theoretical reasons for one system or another. But I do know we have been playing 2/1 for a lot of years and have added good things, taken out awkward things, and developed so many specialized agreements (dependent on other parts of the system) that I am too old to start from scratch with something different.

I can imagine people doing the same thing with whatever basic approach they choose, so IMO for me to debate what is "better" would be silly (for me).
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#4 User is offline   Jinksy 

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Posted 2011-November-13, 17:00

Where are the evangelists when I need 'em? :P
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#5 User is offline   nigel_k 

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Posted 2011-November-13, 17:03

Slams and choice of game hands are important and swing a lot of IMPs. I wouldn't underestimate that.

But many people overestimate what 2/1 bidders lose when they respond 1NT. For example:

- If responder invites in NT and opener declines, the 2/1 bidders can play 1NT intead of 2NT.
- If invites in the major and opener declines, the 2/1 bidders can play 1NT intead of 3 of the major which is probably better.
- If responder has a rebiddable suit and less than GF, then the 2/1 bidders can respond 3 of a minor directly then that's a loss for 2/1 because those bids can't be used for something else. But game forcing hands with a strong minor are a real problem if rebidding the suit is not game forcing.
- If opener raises the response and responder passes, usually there will be a similar auction to three of a minor after 1NT, e.g. 1-1NT-2-3 vs 1-2-3.
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#6 User is offline   Jinksy 

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Posted 2011-November-13, 17:39

I've been discussing with my regular P in particular whether it would help out with Fantunes sequences to have non-GF 2/1. It certainly seems like it would solve a lot of problems with the huge range in responder's hand. Neither of us can see whether it will cause even bigger problems elsewhere.
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#7 User is online   awm 

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Posted 2011-November-13, 19:55

View PostJinksy, on 2011-November-13, 17:39, said:

I've been discussing with my regular P in particular whether it would help out with Fantunes sequences to have non-GF 2/1. It certainly seems like it would solve a lot of problems with the huge range in responder's hand. Neither of us can see whether it will cause even bigger problems elsewhere.


I'd say definitely not on this one. Playing 2/1 helps you when you have the GF hands and hurts you when you don't. Given that you are playing Fantunes-style (i.e. sound openings) responder's GF hands are going to be quite frequent, much more so than in a traditional system. With this in mind I think it makes very little sense to play non-GF 2/1 sequences in Fantunes.

It's not a coincidence that the rise of 2/1 as an "expert standard" method has happened at more or less the same time as IMP events have taken over from matchpoints in many tournament (and even some club) competitions. IMP events emphasize accurate slam bidding over delicate invitational or part-score auctions, which is a good thing for a method like 2/1 (which shines in slam bidding and sometimes struggles finding the best partial).

Perhaps the biggest advantages of 2/1 are not actually anything about the system itself. The fact is that most good players today have more experience with 2/1 than they do with any particular method that doesn't include non-GF 2/1 bids. In the context of a short-term partnership where one doesn't want to spend many hours discussing sequences, it is simply much easier to play 2/1. In addition, a great deal of the development of popular methods in the last decade or two has focused on mitigating some of the problems with the 2/1 system. Obviously similar fixes can/do exist for methods without GF 2/1s, but they are less widely-known, less has been written about them, and the follow-ups may be less fully developed.

Personally I do prefer a structure with invitational-plus 2/1 bids in my serious partnerships, somewhat bucking the trend in the forums. There are a few reasons for this. First, with the tendency towards lighter and lighter openings, I find that frequency favors my approach (obviously this would not apply in Fantunes). If partner's opening lots of ten-counts, the somewhat icky forcing-notrump range gets wider (and more frequent) while the GF range becomes rarer. Second, I personally play a lot of matchpoint and BAM events, to the extent that I'd rather play a system that's more optimized for these events than one which is more optimized for IMPs. Third, I'm fond of tinkering with system and don't mind at all playing "non-mainstream" stuff that helps my methods.
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#8 User is offline   blackshoe 

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Posted 2011-November-13, 19:57

It helps to define what you're talking about. "Is a simple two level response to a one level suit opening better if it's game forcing, or better if it's only invitational?" is one question. "Is 2/1 GF (the bidding system) better than <some other system in which 2/1 is not GF>?" is another question entirely. Comparing "2/1 GF" to "Standard American" where the 2/1 is only invitational, clearly both systems have their upsides and downsides. 2/1 solved a few of "Standard's" problems, and created new ones. On balance, it seems to me that the advantages (primarily in game and slam bidding) outweigh the disadvantages (primarily in part score bidding), but I haven't done a scientific analysis. Do consider that the game and slam bonuses are pretty huge, at least at IMPs.

Frankly, I think the more important question at this point is "what do we do about the erosion in values required for the forcing 2 opening?"
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#9 User is offline   Yu18772 

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Posted 2011-November-13, 21:41

I had been playing 2/1 with my regular partner for ~2 years, before that we were playing natural system where 2/1 responses were invitational with 5 card suit. We are generally quite aggressive bidders, and our rule is "opening versus opening is a game". The reasons we like 2/1GF are - it creates a lot of bidding space which can be used
a. to investigate the right game,
b. to bid stoppers and get to 3NT played by the right side, or vouch out in 4-3/5-2 major when we dont have a stopper or even stop at 4 minor if no choice
c. Slam bidding is much more scientific - this can be a plus or mins, depends on you and p. we like it.
d. it is less precise in partscores, but not by far, imo.

However, its not one system fit all. Discussion of auctions and good understanding between us is WAY more important than natural or 2/1GF systems, and imo a well discussed natural system will outperform poorly discussed 2/1 on any account, given the same partnership.
The advantages also very much depend on what you add to the system - e.g. Bergen and J2NT work very well with 2/1GF, some other conventions less so. Also we much prefer playing semi-forcing 1NT, and 2-way bergen, which is very useful in MP, but these are personal flavors.
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#10 User is offline   blackshoe 

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Posted 2011-November-13, 22:17

"2-way Bergen"? What's that?
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#11 User is offline   Free 

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Posted 2011-November-14, 00:22

I prefer the auction 1-2-2 over 1-2-3 just to show my 4 card suit when I have 15HCP.

There's also a big difference between forcing 1NT response and semi-forcing 1NT response. The first 2 advantages Nigel describes are typical for semi-forcing 1NT. Standard 2/1 doesn't have these.
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#12 User is offline   whereagles 

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Posted 2011-November-14, 03:33

Thinking about it, the greatest advantage of 2/1 GF is that pard won't forget that

1M 2x
2M 3M

is forcing :)
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#13 User is offline   Dutchdwang 

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Posted 2011-November-14, 04:33

View PostFree, on 2011-November-14, 00:22, said:

I prefer the auction 1-2-2 over 1-2-3 just to show my 4 card suit when I have 15HCP.




If you play 2/1 F1, I guess 1-2-2 is forcing, otherwise it seems unplayable to me.
Also 2/1 GF is easy in what's forcing and what's not. You (almost) never have misunderstandings about that.. what i particulary hate about 2/1 F1 is:
1M-2m
3M with a reasonable 14/15 count and not a really good suit, partner has to guess a lot now, you can miss game/slam easily or end up in wrong game..
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#14 User is offline   hrothgar 

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Posted 2011-November-14, 05:02

From my perspective, bidding theory isn't particularly well advanced.

I've never seen much in the way of a compelling proof that method A is inherently superior than method B.
Look at the debates between weak and strong NT. People have been arguing that one for decades.

If I were forced to make an argument in favor of 2/1 GF, I'd focus on the following

2/1 GF is an extremely popular treatment among professionals. In turn

1. This suggests that the methods have some degree of merit
2. There is a large community actively working to improve / optimize the system
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#15 User is offline   gwnn 

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Posted 2011-November-14, 05:10

View PostDutchdwang, on 2011-November-14, 04:33, said:

1M-2m
3M with a reasonable 14/15 count and not a really good suit, partner has to guess a lot now, you can miss game/slam easily or end up in wrong game..

You don't have to bid 3M with a reasonable 14/15 count and not a really good suit. (Unless you play 1M-2m; 2M as non-forcing, which is unplayable in my little opinion...)
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#16 User is offline   mcphee 

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Posted 2011-November-14, 06:16

The issue with a non game force 2/1 are all those 4-4 minor hands with 10-11, the 3 card major support hand in the 9-11 range. These hands are common enough that better methods are required. I do not agree that part score bidding suffers for 2/1 players either. The truth is that 2/1 is hands down better for reaching games and slams in uncontested auctions.Better for imps, you bet it is.

Ask yourself as a player who has used sayc and 2/1, if you were handed the basics of both isn't 2/1 just easier?
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#17 User is offline   EricK 

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Posted 2011-November-14, 06:57

Judging from the replies, one of the perceived problems with 2/1 non-GF (and hence one of the advantages of 2/1 GF) is that there is sometimes no clear idea as to what level 2/1 is forcing. By judicious use of 4th suit forcing, 3rd suit forcing (Bourke relay?) after opener rebids his suit, opener not rebidding 2NT on a balanced minimum, and playing 2/1 forcing to 2NT or 3m/M, you should be able to get the best (or nearly the best) of both worlds.
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#18 User is offline   gwnn 

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Posted 2011-November-14, 07:06

Either way, in 2/1 you have a handy 2N waiting bid for responder in auctions like:

1-2
2/-2N

and this can make much more defined rebids by responder, e.g.

1-2
2-3=5-5
    -3=very good 6 carder

if you don't play 2/1, your 3 will not even promise a 4-card suit, let alone a 5-5, and 3 will be non-forcing.
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#19 User is offline   MickyB 

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Posted 2011-November-14, 07:11

View Postgwnn, on 2011-November-14, 05:10, said:

You don't have to bid 3M with a reasonable 14/15 count and not a really good suit. (Unless you play 1M-2m; 2M as non-forcing, which is unplayable in my little opinion...)


Disagree with the contents of your parentheses. Playing 1M:2m, 2M as F1 is clearly wrong in my opinion, why would you design a system around stopping in 2NT?

The hands you really want to 2/1 on are 9-10 with a doubleton in partner's suit so you can split up the 4-10 range for auctions like 1S:1N, 2H:2S.

I agree with the assessments on having to bid 1S:2D, 3S with many hands and 1S:2D, 2S:3C as just a way to force; That is why I play 1S:2D, 2NT as GF single-suited and 1S:2D, 2S:2NT as GF [invites bid 1NT then 2NT].
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#20 User is offline   gwnn 

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Posted 2011-November-14, 08:18

I stand corrected. That (<- the system you described) might be a playable system :)
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