4th suit forcing after 1C - 1D - 1H

[mikeh]

At the risk of reopening an old thread of which I am unaware (those with long and better memories should feel welcome to point me to that thread if it exists), I was struck by a recent post on another thread by the suggestion that one bids 4th suit in the auction 1♣ 1♦ 1♥ by jumping to 2♠.

 

My own preference has long been to use 1♠ here as 4th suit. Now, I admit that this may be playable only in a strong walsh style, in which responder bids 1♦ with a 4 card major only when strong enough to force to game. If you belong to another school, then you will need to be able to bid 1♠ naturally without thereby forcing to game.

 

So, there is no need to post opinions based on such schools... I am asking only for opinions for and against using 2♠ in the given auction in the strong walsh style.

 

I have my own thoughts (wow, what a surprise :( ) but I'd like to hear how forum members think about it. As a hint of my thinking, I have problems with the notion of voluntarily consuming an entire level of bidding merely to force to game, while conveying virtually no other useful info to partner. Since there are good players who use 2♠ in this context, I assume that they have arguments as to why this is a reasonable price to pay.

 

While I am at least as obstinate as most players, maybe I will be persuaded :lol:

[Limey_p]

I'll leave the learned discussion to others. This is an area where I want to have an agreement, and I don't much care what it is, so long as pard and I are on the same page.

 

AP

[mike777]

Granted playing 1s as natural and game forcing will be a bit rare in Walsh. Opener is showing 5clubs and 4hearts and responder has a game force hand with at least 4+d and 4 spades and not longer spades than diamonds.

 

If responder has long D and a game force hand and less than 4 spades what are her options if partner starts out 1c=1d=1h=?. Remember in Walsh this shows 5clubs and 4 hearts. If playing XYZ then responder can rebid 2D as game force. I guess with a weakish hand and playing XYZ you cannot rebid 2c(invite) or 2d(g/f) and you need to discuss how you want to play 3c or 3d?

 

Let's assume that 2c or 2d rebid by responder is natural and weakish what then? I guess you need to bid 2s as 4sf?

[SoTired]

not walsh: 1S = nat, F; 2S=art, GF

 

Walsh: 1S=art, GF; 2S=art, GF, club raise, req for q-bid

 

Both bids are GF. Most play that 1S could be anything including 4-card heart support which will be shown next round. 2S is specifically a strong club raise looking at club game/slam before passing 3N. Not everyone plays it this way. Others play the 2S as nat, GF and 1S as art GF or visa-versa.

[mikeh]

Granted playing 1s as natural and game forcing will be a bit rare in Walsh. Opener is showing 5clubs and 4hearts

Not true... close, but not true.

 

The auction 1♣ 1♦ 1♠ shows 4+=5+ in the blacks, but 1♣ 1♦ 1♥ may be 4=4=1=4.

 

And in this treatment, there are compelling reasons to keep a preference by responder to 2♣ as natural and non-forcing. And to allow 2♦ to be natural and non-forcing.

 

As for rarely needing to respond 1♦ and then rebid 1♠, again, I differ. It is precisely how a responder with 4+♠, and longer ♦ and a gf hand should bid.

 

I was not proposing that the sequence 1♣ 1♦ 1♥ 1♠ deny ♠... I was suggesting that it be neutral on the length of ♠... anywhere from 0 to 5, with 5 being very rare indeed.

 

After all, after 1♣ 1♦ 1♥ 1♠ if opener has 4♠, he raises to 2♠ and responder has very useful distributional info and is captain in the auction... compare to having to jump to 2♠ as the artificial force... what is opener to rebid with 4=4=1=4 or 4=4=5=0? If he has to pattern out (knowing that partner lacks 4♠) then the partnership is at 3♠ with no fit yet established... if responder was coming in ♥'s, how does responder differentiate between mild and real slam tries with ♥?

 

And if opener is not to pattern out, how is responder supposed to judge degrees of fit?

 

Oh well, I am descending already to argument... but I have yet to read from anyone what the advantages are of hijacking one's own bidding space.

[mike777]

Thanks for a very interesting post and time killer for me at work this afternoon. :)

Now that I am home I have continued this discussion via emails with some friends.

 

In a Walsh 2 way checkback, not xyz context and given 1c=1d=1h=1s is natural, game force with 4s and 1c=1d=1h=2s is 4sf here is where we stand so far....:)

 

"oh yeah....you also have 4 clubs when you are 4-4-1-4, hehe.....

 

This is so rare an auction....I can't rembember it ever coming up.....after all, responder has no 4 card major, and yet has a forcing hand in diamonds...where he doesn't just want to play 3NT....'

 

Opener rebids naturally as we do in all these low level game forcing auctions.....with these patterns that have no diamond fit, rebidding 2NT or 3NT (with a minimum) seems attractive to me.

 

Wouldn't 3S imply a fit for pard...then again if you have a fit, why not just bid 3D first to make it official?

 

As this auction won't come up until long after we've forgotten this discussion, I think I'd avoid bidding 3S altogether, as pard wont know what it means.....I'll bid NT, which tends more towards having spades stopped and towards not fitting diamonds well OR i'll bid 3D with any kind of diamond support, especially if i can't stop spades, OR I'll rebid clubs to suggest extra length/strengh there.

 

This certainly covers hands such as the 2-4-3-4 hand without a spade stopper...(i'd bid 3D)....

 

Flat minimums such as 3-4-1-5,,,,,,,,(3NT, with spades stopped....3C, w/o spades stopped)

 

extras with 3-4-1-5, i'd bid 2NT, assuming spades stopped....

 

4-4-1-4.........3NT with minimum, 2NT with extras....

 

4-4-0-5.........probably rebid NT here too. might say 3C

 

2-4-2-5.........either NT or 3C depending on my honors....maybe even 3D...with: xx Axxx KQ QJxxx

 

1-4-3-5.........3D"

[kenberg]

I mentioned 1C-1D-1H-2S as fsf on another thread. On that thread it seemed clear Walsh was not being played since opener held 4-4-2-3. Playing Walsh, opener rebids 1NT with that shape, or at least I do when playing Walsh.

 

 

I often do not play Walsh (I prefer not to but will play it with those who like it), and when not playing Walsh I regard 1C-1D-1H-1S as a completely natural auction: forcing, showing spades, possibly only modest values. Certainly not game forcing. If partner raises to 2S, this could well be followed by a pass. Similarly if he makes any minimum rebid.

 

In Better Bidding with Bergen, page 5, Marty addresses (slightly) the Walsh version of 1C-1D-1H-1S. He says it shows a good hand, he doesn't say if it shows four spades. Either player, or both, after 1C-1D-1H could have four spades, but responder will have four only if he has a good hand. Back from Marty to me now. It seems the auction 1C-1D-1H-1S is fsf, playing Walsh. Opener could have four, and tentatively raises to 2S if he does. Then we find out if responder's spades are real or if he has something else in mind.

 

Ken

[mikeh]

 

In a Walsh 2 way checkback, not xyz context and given 1c=1d=1h=1s is natural 4s and 1c=1d=1h=2s is 4sf here is where we stand so far....:)

 

"oh yeah....you also have 4 clubs when you are 4-4-1-4, hehe.....

 

This is so rare an auction....I can't rembember it ever coming up.....after all, responder has no 4 card major, and yet has a forcing hand in diamonds...where he doesn't just want to play 3NT....'

 

Not true :)

 

Responder may well have a 4 card major even for those who use the jump to 2♠ to deny 4♠... he may have a 4 card ♥ suit!

 

1♣ 1♦ 1♥ is very wide range... opener can be anywhere from minimum (whatever that is for you) to just short of a jump shift.

 

So responder will almost never be able to risk jumping to 4♥ and may be unable to splinter.. that still leaves a lot of hands... and neither 2♥ nor 3♥ are forcing.

 

So responder, with many, many hands with 4=5+ in the reds will use 4sf. He intends to bid a minimal number of ♥ at his next turn, to show a gf or better raise in ♥.

 

My concern is that will, after a 4th suit 2♠, this revelation of a ♥ fit be made at the 3-level or (ugh) the 4-level. If at the 4-level, after opener bids 3♠ or 3N, we have a real problem: how is opener to know if the 4♥ was to play or setting trump for cue-bids or (your favourite, Mike) keycard?

 

If at the 3-level, then at least responder knows that opener will bid again, but there is very little room left and neither opener nor responder have made much headway in describing their hands.

 

So far, I have seen nothing that suggests that there is ANY benefit to playing 2♠ as the 4th suit... I have seen suggestions as to HOW to play after using it, but why use it at all? Where does it out-perform using 1♠ as a catchall gf, silent on the ♠ length, and a whole level lower???

[mike777]

Thanks again for this thread. If I understand your argument you are worried about a responder hand that is game force with hearts?

 

Perhaps a good goal here is to make as many bids as natural, logical and as frequent as possible. If 2s as 4sf is pretty rare that makes it better to play 1s as natural and not 1s as 4sf.

 

1c=1d

1h=2h=game forcing. We are playing Walsh! :)

 

For those readers not familiar with Walsh all hands with less than game force and 4+ hearts start with 1C=1H.

Yes, as I have discussed in other threads that leaves the invite hands with longer D and 4 hearts with no completely satisfactory solution. There are many partial solutions but in practice you must choose to live with this problem. In practice it is rarely an issue but one you must choose to live with.

 

 

 

"......both 1S and 2S rebids are rare....so I would think one way of deciding which should show the spades, is which comes up more often....(the one suited slam try OR Diamond-club two-suited slam try, assuming you respond in diamonds, and upon hearing pard has real clubs, you now wanna bid a club slam) OR the two suiter game or slam going hand with Diamonds and Spades. This is pretty close....

 

I think because of it's rarity, and because of how I explained the rebids over 2S, we are okay to leave it alone. The less we mess with, the less chance we have of the real tragedy of screwing up our agreement when it does come up.

 

As I explained...Over 2S, Opener is is going to support diamonds just about whenever he can....So if responder had the big diamonds with clubs hand and opener supports diamonds over 2S, he can pretty much just go for it in diamonds. If

opener doesn't support diamonds (by rebidding NT or clubs), responder can now raise clubs and go for it there....remember if opener has extras he'll bid 2NT (not 3NT), making it easier for responder who can now bid 3C.

 

this auction:

 

1C 1D

1H 2S

3C 4D (is kickback for clubs....responder can rebid 3D to press on in diamonds and anything else to fish for 3NT or play in clubs)

 

1C 1D

1H 2S

2NT ?? 3C sets clubs, 3D is pressing on in diamonds.....(you shouldnt bid 3 of a major as its ambigious)

 

REMEMBER

 

1C 1D

1H 2H (is GAME FORCING)

 

 

See, what I'm doing is logically figuring out what bids should mean, NOT ...making up a lot of new stuff to ...confuse......"

[luke warm]

i can't think of many good reasons for a 2S bid there, unless it shows a gf hand agreeing hearts (is that possible? can it profitably be used as a splinter?)

 

1c : 1d

1h : 1s

 

shows either a gf hand with 4+/4+ spades/diamonds (= or > ♦) else ambiguous gf... opener has 4 hearts and longer clubs else 4414 (edited comment, 2 or 3D would always be bid with 1444)...

[mikeh]

 

1c=1d

1h=2h=game forcing. We are playing Walsh!

 

Sorry, Mike.... I am enjoying your posts, but I again have to disagree. As I wrote in my post on the thread of 1♣ 1♦ 1♥ 2♥, for me the raise to 2♥ on 3 cards is not just okay (not on the given hand, but in principle) but essential on hands such as xx KQx Axxxx xxx.

 

This type of hand can survive sometimes by bidding, for example, 2♣ but let's give opener Jxx AJ10x x AKQxx... I'd like to be in 4♥, wouldn't you?

 

It is ok and sometimes necessary, in the design of a bidding system, to accept that your methods will inevitably lead to poor results on certain hand types. But one should minimize this situation, and only accept it if co-opting the 'normal' sequence will solve other, more important issues.

 

And there are ways to solve the hand on which responder, after bidding 1♦, has a gf hand with 4♥ without sacrificing the ability to make a descriptive, non-forcing 2 call with the type of hand I gave.

 

I suspect that I am not making my concern clear. I read, in that other thread, of the idea that responder, with a gf hand and lacking 4♠, should jump to 2♠ as an artificial gf (4sf).

 

Your last post carries within it the assumption that responder HAS to differentiate between holding a gf hand with 4♠ and a gf hand without 4♠. I understand that that is the rationale used by the 2♠ gsf school to explain why they 'need' to jump to 2♠.

 

My concern is WHY? Why is this assumption valid? What advantages flow to the partnership from using this approach?

 

I say: very few... but since a lot of players use the method, either they have not considered the alternative (using 1♠ as content-free in terms of announced ♠ length) or they are too lazy to change or I have missed something important.

 

For me, it seems apparent that there is NO need for responder to announce anything at all about his ♠ length at his second bid. He uses 1♠ merely to say: 'we're going to game... make a descriptive, economical bid and I will tell you which suit I'd like to suggest we consider as trump... or I will bid the appropriate number of notrump if my thoughts lie that way after hearing a 3rd descriptive bid from you'.

 

The partnership will find ALL fits, and will find all such fits at a level lower than after an artificial 2♠.... with the sole exception of the sequence 1♠ 2♠.

 

Using 1♠ as natural and GF means that the fit is established at 2♠. Using 1♠ as ambiguous means that responder has to raise ♠ to 3 or 4♠ to agree trump... with any slam interest opposite opener's 4=4=1=4 or 4=4=0=5, almost unlimited hand, he bids 3♠.

 

That one auction is worse than the 2♠ 4sf sequence but EVERY OTHER auction is significantly easier.

 

So am I missing something? Is there some other advantage to using 2♠ as 4sf in this auction?

[mike777]

"My concern is WHY? Why is this assumption valid? What advantages flow to the partnership from using this approach?"

 

 

Ok it is clear we are playing 2 very different bidding systems.

1c=1d

1h=2h is game force 100% in my style.

 

Maybe some late night I can get a hold of John Swanson and ask him what the official meaning is of this auction :).

 

To really answer your question we need a working definition of Walsh :).

 

Again with my methods I think the argument is to use 4sf as little as possible and use natural bidding as much as possible. To repeat the advantage I am claiming; if we accept that 4sf auctions inherently are more error prone that is a good argument against using 1s as 4sf. The advantages are three, more natural, logical simple continuations in the context of the entire system, more frequent. I do not know which is better in theory. I do not argue that as an advantage. I do argue that simple and natural in this case outweighs any theoritical advantage that a 1s as 4sf claims. I hope this is a clear and direct answer to your initial question.

[Winstonm]

I play 1S as natural with Walsh and here are my reasons:

 

1) I do not sacrifice a natural bid if the gain is not clearly better.

2) 1S is more descriptive as unbalanced or consolidated strength and allows flexibility to bid 1N with a flatter hand pattern or a hand that looks like a weak nt.

3) Partner may want to play 1S.

4) If partner wants to play 2D he can do so.

5) The added room saving to me is not of enough value to overcome numbers 1-4 above.

[helene_t]

If you play Walsh, the 1♥ bid is quite descriptive so whether responder wans to show spades or to make a generic force, you can live with the loss of bidding space that comes from a jump to 2♠. So I guess either method is playable. It depends how nebolous your fsf is. If any GF hand (other than those that would bid 3NT) goes through fsf, I strongly prefer playing 1♠ as fsf. In other styles (e.g. with intermediate jump shifts so responder's 3♦ as second bid would be forcing), it doesn't matter that much.

 

But there may be better uses for 1♠ than either natural or fsf. You could play it as a waiting bid that doesn't need to be strong, such as a hand that wants partner to declare in 1NT. This is a generalization of fsf.

 

If you don't play Walsh, you clearly can't afford to jump to 2♠ to make a generic force because 1♥ is not very descriptive, especially in a short-club system. This means that even if you don't play Walsh, responder will have to bypass diamonds when he has spades also. This is a little awkard when responder has 4♠6♦. But don't worry too much about it. Natural follow-ups to a natural 1♣ aren't supposed to be rocket science anyway.

[mike777]

If I understand this thread we have 3 options after 1c=1d=1h=?

1) 1s as 4sf is winning bridge

2) 1s as natural game force with 4s is winning bridge

3) there is no significant winning bridge choice.

4) are we playing xyz where 2c here is invite and 2d rebid =game force?

 

AGAIN I assume:

1c=1d

1h=2h=game force

[mike777]

"But there may be better uses for 1♠ than either natural or fsf. You could play it as a waiting bid that doesn't need to be strong, such as a hand that wants partner to declare in 1NT. This is a generalization of fsf."

 

I have no idea what this means?????

[Finch]

I am a bit surprised that the only options being offered seem to be 1S as 4sf game forcing or 1S as natural game forcing.

 

I play in two regular partnerships. One has a 'mild' Walsh style (where you respond 1D with a 4CM if you are INV+ opposite a weak NT) and doesn't play 4sf as game forcing at the 2-level either. We'll ignore that one for this thread.

 

The other regular partnership plays Walsh, plays 4sf as game forcing at the 2-level, but plays 1S as simple fourth suit forcing, not game forcing (i.e. opener's minimum rebid can be passed). This seems to be what helene_t was trying to describe.

 

1S shows mildly invitational values (or stronger) and nothing particularly to say about the hand. Opener's minimum rebid of 1NT, 2C, 2D, or 2S (showing a 4144) can be passed. Responder's typical shape for the non-game forcing hand is 3352 without much stuffing in spades. Responder might also have a game force with club or heart support, or be lacking in the spade stop department (we play 1C - 1D - 1H - 3D as game forcing, so responder can't be strong with diamonds). This allows you to try for game on as little as 9-10 count and play in 1NT if partner is minimum, without forcing partner to make a game try over a simple preference on a 16-count or so.

 

That leaves the 2S bid as currently meaningless. There are various good uses it can be put to: coming immediately to mind are game forcing with club support, game forcing with heart support, game forcing with 4 spades.... we happen to play 2S as invitational with 3-card club support, not suitable for a 2NT bid (in particular no strong desire to be declarer) - the hand that would usually bid 3C, but doesn't want to play in a 4-3 fit opposite a 4414. I guess it could also be a slam try with 3 clubs, but that's never come up....

[Codo]

Some partners forced me to play it one way or another, but what I like best is: 1 Spade is natural and/or 4sf.

So, you can bid the hands with 3 card heart support or any other hand this way and any hand with 4 spades.

This leaves the later bidding quite easy, because it works like always after 4sf.

 

There is just on little trap: If opener holds a 4405 or 4414 hand with extra strength, he needs a bid below 3 Spade to show this pattern and extra strength.

Solution is the "impossible jump" to 3 Hearts, a bid that you simply do not need for different purpose.

 

P.S. In my book, 1 Club 1 Dianomd 1 Heart 2 Heart is gameforcing too.

[1eyedjack]

There is just on little trap: If opener holds a 4405 or 4414 hand with extra strength, he needs a bid below 3 Spade to show this pattern and extra strength.

Solution is the "impossible jump" to 3 Hearts, a bid that you simply do not need for different purpose.

Just out of interest, what benefit is there in showing that hand by 3H rather than 3S?

[kenberg]

I want to phrase this carefully, since mikeh rightly doesn't want this to turn into a discussion of the merits of Walsh. I will speak of my own limitations, although they seem to be shared. My guess is that Walsh works fine, quite possibly better than standard, providing everyone agrees on what the follow-up bids mean. Often I have no idea. To my mind, after 1C-1D-1H, I may hold a hand whee I would like to send the message: "Unless your spades are better than mine, no trump is out but we might be able to play in our 4-3 heart fit." Something like 10 hcps, strong hearts, short spades would seem to be about right. Others say no, raising the second suit shows four, and therefore is gf. I have no idea which treatment is standard in Walsh, and I don't really have any idea as to how to find out. Read Hardy maybe? Is this accepted as the Walsh authority? I repeat, this is very much my own limitation, not a limitation of the system and I disavow any desire to get into a debate over whether Walsh is or is not the way to bid a hand.

 

Ken

 

 

PS Mike commented in one of his follow-ups on the 2S as fsf on the "other thread". So let me say again, that was definitely not a Walsh auction. Walsh players are not 4-4-2-3 when they rebid 1H (as was the case there). I'm pretty sure we are in agreement that playing non-Walsh, 1S is natural and 2S is fsf.

[Codo]

There is just on little trap: If opener holds a 4405 or 4414 hand with extra strength, he needs a bid below 3 Spade to show this pattern and extra strength.

Solution is the "impossible jump" to 3 Hearts, a bid that you simply do not need for different purpose.

Just out of interest, what benefit is there in showing that hand by 3H rather than 3S?

Sorry for not clarifying:

3 Heart can show both hands with strong invitational strength (16-18) or GF strength (19+) And for the later hands you need a forcing bid below 3 NT.

[mikeh]

I am a bit surprised that the only options being offered seem to be 1S as 4sf game forcing or 1S as natural game forcing.

 

I play in two regular partnerships. One has a 'mild' Walsh style (where you respond 1D with a 4CM if you are INV+ opposite a weak NT) and doesn't play 4sf as game forcing at the 2-level either. We'll ignore that one for this thread. 

 

The other regular partnership plays Walsh, plays 4sf as game forcing at the 2-level, but plays 1S as simple fourth suit forcing, not game forcing (i.e. opener's minimum rebid can be passed).  This seems to be what helene_t was trying to describe.

 

1S shows mildly invitational values (or stronger) and nothing particularly to say about the hand. Opener's minimum rebid of 1NT, 2C, 2D, or 2S (showing a 4144) can be passed. Responder's typical shape for the non-game forcing hand is 3352 without much stuffing in spades.  Responder might also have a game force with club or heart support, or be lacking in the spade stop department (we play 1C - 1D - 1H - 3D as game forcing, so responder can't be strong with diamonds).  This allows you to try for game on as little as 9-10 count and play in 1NT if partner is minimum, without forcing partner to make a game try over a simple preference on a 16-count or so.

 

That leaves the 2S bid as currently meaningless. There are various good uses it can be put to: coming immediately to mind are game forcing with club support, game forcing with heart support, game forcing with 4 spades.... we happen to play 2S as invitational with 3-card club support, not suitable for a 2NT bid (in particular no strong desire to be declarer) - the hand that would usually bid 3C, but doesn't want to play in a 4-3 fit opposite a 4414.  I guess it could also be a slam try with 3 clubs, but that's never come up....

My post was triggered by a very specific issue: the existence of two specific schools of thought as to 4th suit in the specified auction in a specific (strong walsh) school. Which is why there were only 2 options on display :P I was not implying that these two are the only options :D

 

I still have not seen any logical analysis of why one might choose to play that 1♠ shows ♠s (and is gf because of the walsh implications) and 2♠ is gf without ♠, so I am going to conclude that either none of the readers of the thread play the 2♠ in this fashion or that, if they do, they have not articulated why.. perhaps not even to themselves :)

 

I like the idea of putting the otherwise meaningless 2♠ jump to a specific use: I am about to start playing again with my partner of 6 years ago, and perhaps I will bring it up with him. But I am still going to use 1♠ as a generic gf, because we have an excellent relay structure thereafter.

[Echognome]

In a Walsh structure, it would seem that using 1♠ as natural (responder's reverse hand) is not extremely useful. I will argue this mainly on frequency grounds. Furthermore, using 2♠ for that bid is probably not a big loss.

 

I looked in my Hardy book and the only thing he mentions with XYZ are the 2♣ bid forcing 2♦ (as invite or sign-off in ♦), 2♦ as ART GF, and 3♣ to play (mikeh's 2NT variant seems an improvement here).

 

I think one can make an argument to play transfers here:

 

1♠ --> 1NT (either to play or the start of an invite sequence)

1NT club support (either to play or GF)

2♣ long diamonds (either to play or GF)

2♦ good heart raise GF

2♥ bad heart raise

2♠ natural GF

 

With higher bids being heart raises. The only problem with this system is that it doesn't translate that well to other sequences (despite its great efficiency here).

[mike777]

"Sorry, Mike.... I am enjoying your posts, but I again have to disagree. As I wrote in my post on the thread of 1♣ 1♦ 1♥ 2♥, for me the raise to 2♥ on 3 cards is not just okay (not on the given hand, but in principle) but essential on hands such as xx KQx Axxxx xxx.

 

This type of hand can survive sometimes by bidding, for example, 2♣ but let's give opener Jxx AJ10x x AKQxx... I'd like to be in 4♥, wouldn't you?"

 

 

Difficult Deal:

1C=1D

1H=2C

3C=3H

4H

[awm]

I've been reluctant to contribute to this thread because I'm not a believer in Walsh style responses. Personally I play 1♠ natural and 2♠ artificial because I like to bid my suits in natural order instead of skipping diamonds. :P

 

But in any case, it seems like there are many advantages to playing 1♠ as artificial and forcing using Walsh style. After all responder won't have a four card spade suit without game values and opener usually won't have four spades either to raise (except 4-4-1-4 and 4-4-0-5 exactly).

 

On the other hand, I'm not convinced that setting up a game force at the one level is the best use for this bid. There are a number of difficult invitational hands that become hard to bid. For example:

 

(1) Invite with three clubs and no spade stopper. Bidding 2NT seems weird, bidding 3♣ might get you to a 4-3 fit if partner is 4-4-1-4.

 

(2) Invite with five diamonds or six bad diamonds. Again you could bid 2NT, but it's easy to imagine the hand playing a lot better in diamonds (1435 or 2425 with weak spades).

 

(3) Invite with three hearts and a ruffing value. I suppose you can bid 2♥ if you play this as three-card support (and thus not GF) but wouldn't you also bid 2♥ with some 8-count? It seems like 8-12 is a wide range for this raise.

 

Seems like 1♠ as "inv+ fourth suit" would have many advantages, which seems to be what Frances is suggesting as well. Matt's transfer scheme is nice but might be a lot to add if it only comes up in the one auction. In fact one could distinguish between 2♠ = artificial GF wanting to set the suit at next turn (opener bids 2NT and then 3♣/♦ set-suit slam tries) and 1♠ = artificial inv+ no clear direction.