[relknes]

I realize that there are a lot more than the ones listed, but these three seem to represent the basic styles that people prefer, so pick the one that most closely resembles what you think of as the best structure.
My current thoughts are in the spoiler text below.

Spoiler

1. Pass forces redouble structures
Advantages: puts pressure on doubler to act before they know if you want to play 1Nxx, allows you to play 1Nxx when appropriate, sometimes allows you to find a slightly better 2y contract than the other methods.
Disadvantages: you can never play 1Nx, even if it is the "least bad" contract.

2. Totally Natural bidding
Advantages: easy to remember, allows you to play either 1Nx or 1Nxx at responder's discretion.
Disadvantages: you will miss 2y when there is a 4-4 fit that is better than 1Nx, and sometimes play a 5-2 fit when a 4-4 fit was available.

3. Natural bidding with S.O.S. redoubles
Advantages: You can play 1Nx when responder wants to, and you can force opener to start the scramble when you don't have a good suit of your own
Disadvantages: You can never play 1Nxx, even if that is a great contract.

1 seems best when 1Nx is not the best contract, but potentially much worse when 1Nx is best.
2 seems best when responder is not 2 suited or 3 suited.
3 seems like a sort of compromise structure that tries to "cover all the bases" adequately without being the best in any particular circumstance.

I currently like 1 because it seems to do a little better most of the time.

[Mbodell]

It depends on your opponents and how likely they are to sit and bid and what not. But I find a high percentage of the time 1ntX is the right spot to play, and only some of that time will 1ntXX be right, so I think pass forcing XX is terrible. There are ways to get many of the one suited and two suited hands all at once with various flavors of suction. My preferred method is:

As an UPH:
Pass - strong suggestion to play (partner can self run with unusual shape, like a 6m)
XX - business, they've made a mistake ("same hand or better Xers" run into this not uncommonly)
2♣ = 2 suiter with ♣ and ♦ OR 1 suiter with ♥, not forcing
2♦ = 2 suiter with ♦ and ♥ or 1 suiter with ♠, not forcing
2♥ = 2 suiter with ♥ and ♠ or 1 suiter with ♣, not forcing
2♠ = 2 suiter with ♠ and ♣ or 1 suiter with ♦, not forcing
2nt = 2 non-touching suits
3 level => as the 2 level
4♣ => transfer to hearts
4♦ => transfer to spades
4♥ => to play
4♠ => to play
(the bids above the 2 level are 1 in 100 or less, but have come up at least twice for me).

As a passed hand (either initially, or over the 1nt bid, a pass shows we don't have game, so now XX for business makes very narrow sense and we repurpose):
Pass - to play
XX - please normally bid 2♣, this will either be a 1 suiter with ♣ (I'll pass), a 1 suiter with ♦ (I'll correct to 2♦), a 2 suiter with ♣ and ♥ (I'll usually bid 2♥, although especially white I might just pass if not doubled), a 2 suiter with ♦ and ♠ (I'll correct to 2♠).
The rest as a UPH, although a bunch of the hands are covered in XX so unlikely to be the second meaning.

When the 1nt bidder wants to self run I like the passed hand method since the 3 most common hands to want to run are single suited clubs, single suited diamonds, and both minors.

With one partner for the UPH we switch from inverted psycho suction to regular psycho suction (so each bid shows either a 1-suiter with the suit bid, or a 2-suiter with the next 2 suits, non-forcing), which also allows single suited minor run outs better, but at the cost of slightly higher likelihood of playing misfits.

For both weak nt and mini nt I think the above works very, very well.

[steve2005]

none of the above. your not close to covering all the possibilities. anyways to each their own.

[nige1]

steve2005, on 2014-July-07, 18:42, said:

none of the above. your not close to covering all the possibilities. anyways to each their own.

My preferred rescue variant:

1N (X) ??

• Pass = NAT. To play. (Usually).
  
• XX = SOS. 2 or 3 suits.
• 2♣/2♦/2♥/2♠ = NAT. 5+ cards or TFR Weak. (Alert).
  

1N (_X) _P (_P)
??

• Pass = NAT. (Usual action).
  
• XX = ART. 5-card suit. (Optional action).

1N (_X) _P (_P)
XX (_P) ??

• Pass = NAT. Good hand.
• 2♣ = ART. Pass or correct to 5-card suit.

1N (_X) XX (_P)
??

• 2♣ = ART. No other 5 card suit.
• 2♦/♥/♠ = NAT. 5 cards. (Usually ends auction).

1N (_X) XX (_P)
2♣ (_P) ??

• Pass = ART. 4+ ♣ or ♦ & ♥.
• 2♦ = NAT. ♦ & ♠.
• 2♥ = NAT. ♥ & ♠.

1N (_X) XX (_P)
2♣ (_X) ??

• Pass = NAT, 4+ ♣ & 4 + other.
• XX = SOS. ♦ & ♥. (Redouble = red).
• 2♦ = NAT. ♦ & ♠.
• 2♥ = NAT. ♥ & ♠.

Similarly

1N (_X) XX (_P)
2♣ (_P) _P (_X)
??

• Pass = NAT. 3+ ♣,
• XX = SOS. ♦ & ♥. (Redouble = red).
• 2♦ = NAT. ♦ & ♠.
• 2♥ = NAT. ♥ & ♠.

Note When opener has no 5-card suit and fewer than 3 ♣, then he must be 4-4 in two suits.


1N (_X) 2♣/2♦/2♥/2♠ _X
_P (_P) ??

• _P = NAT. Normal action.
• XX = TFR. To next suit.

Features

• (Usually) when responder has flat grot, play in 1N doubled, rather than 1N redoubled or 2 of a suit doubled.
• (Usually) when responder has a 5-card suit, bid final contract immediately.
• (Exceptionally) when responder has a 5-card suit and a very weak hand then, "transfer", to right-side contract and confuse opponents.
• When responder has two suits, try to find a 4-4 fit (preferably a major, which is harder to double).
• (Exceptionally) when opener has a 5-card suit, give responder the option to rescue to it.

[steve2005]

nige1, on 2014-July-07, 18:57, said:

My preferred rescue variant:

1N (X) ??

• Pass = NAT. To play (usually).
  
• XX = SOS. 2 or 3 suits.
• 2♣/2♦/2♥/2♠ = NAT 5+ cards (edit: but not a potential transfer)
  

This too is what I like very simple, but we do have meanings for 2N and 3 of suit

[awm]

There are some other negatives to pass forcing redouble besides the inability to play 1NTX.

You give opponents extra ways to run, for example:

1NT - (X) - Pass! - (2suit) = bad hand, five card suit
1NT - (X) - Pass! - (Pass) - XX - (Pass) - Pass - (2suit) = scramble, cheapest four-card suit

In fact you also give opponent in direct seat the ability to run:

1NT - (X) - Pass! - (Pass) - XX - (2suit)

This might help opponents find game in a suit if doubler has a shapely hand, for example. It also muddies the waters in that opener has no idea whether responder has a good hand here (since he could have been preparing to run, or preparing to pass 1NTXX).

To make matters worse, I've had a number of director rulings that a long hesitation by partner does not prevent doubler from removing his own penalty double after opener's forced redouble (even on a relatively flat hand). This allows opponents to effectively play that a "slow pass" by advancer shows a hand that wants to run but without a five-card suit, after which doubler bids a five-card suit of his own!

[relknes]

steve2005, on 2014-July-07, 18:42, said:

none of the above. your not close to covering all the possibilities. anyways to each their own.

I was trying to differentiate between broad categories, basically those that use both Pass and XX as forcing vs Pass as natural and XX as forcing vs those who use both Pass and XX as natural. I was probably too specific with the pass as forcing system, but I wanted to give some sort of example. Is there some other broad category that I missed? I don't know of anyone who plays Pass as forcing and XX as natural, so I didn't include it, but I suppose anything is possible...

[1eyedjack]

Why can't posters remember (or be bothered) to append "other" as a poll option? It borders on arrogance to assume that you have thought of the only viable options.

EDIT - sorry I see that the point has already been made
Anyway, now that I know that I am supposed to vote for "closest fit", I have done so.

You might have phrased the poll "Which of the following represents the closest approximation to your preference?"

As phrased in the OP it is potentially confusing. Does "best" mean "best from among the options presented"? Or does it mean "best from all possibilities"? Clearly the OP intended the former.

[steve2005]

relknes, on 2014-July-08, 12:31, said:

I was trying to differentiate between broad categories, basically those that use both Pass and XX as forcing vs Pass as natural and XX as forcing vs those who use both Pass and XX as natural. I was probably too specific with the pass as forcing system, but I wanted to give some sort of example. Is there some other broad category that I missed? I don't know of anyone who plays Pass as forcing and XX as natural, so I didn't include it, but I suppose anything is possible...

Pass - natural

redouble sos ( 2 or 3 suits)

[Zelandakh]

This is a topic that comes up often and there are some strong opinions on both sides of it. For example my experience contrasts strongly with Mobodell's in that I find 1NTX to be the right contract rather rarely. More often we go, for example, -1 in both 1NT and 2 of our suit contract for a wash. I have posted many times my take on Spelvic, which includes pass forcing redouble while attempting to fix the Achilles heel of most Helvic structures, the weak 4333 hand (search for it if interested).

Interestingly I also played with a Novice today whose card included Helvic but was otherwise Basic Acol. She said this was because her teacher is so good. Personally, this would not be high on my priority list for a new player. It actually came up too but the opps bid over my XX before I could find out if we were going to have a misunderstanding. Which raises the real truth - the "best" system is the one that you and your partner will both remember.

In any case, the first point of call for a pair looking to choose a runout scheme is David Stevenson's website, although I have had some issues with it since he switched hosts. There the schemes are divided into 4 groups depending on whether pass is forcing and if redouble forces 2♣. Your 3 options miss out the "pass forcing, XX forces 2♣" case, which is a large and important family of runouts of which Helvic is the most influential (and Spelvic a variant of that). Others will correct me if I am mistaken but I believe this group is also the most commonly played amongst the (few) top players still using a weak NT.