[pilowsky]

I was chatting with a partner of mine the other day and the question of what to bid in a 2/1 auction when you open 1♥ and your partner - a passed hand - responds 1NT and you have a 5332 shape.
I know that it's definitely forcing for one round and with my 5332 (15.5%) shape I didn't want to repeat my hearts since that would show 6. So, in order to keep the bidding at the lowest possible level, I chose 3♣ even though I only had 3.

I was a little surprised that GIB took that as an appropriate bid but was even more taken aback by North's response.
2♠ ALERT "impossible spade -- 4+ ♣; 2-♥; 11- HCP; 11-12 total points; forcing to 3♣"

Effectively, a transfer to 3♣. In the end, I'm not entirely sure why GIB felt it necessary to roll out this wonderful gadget and not just raise the clubs.
North is a wily customer. It's a good thing I play with GIB a lot and carefully study the system notes so that I know about the impossible spade, I think there is a comprehensive description of its use on page 112.

At least I'm 3.7 IMP's up.
As you know, hands in BBO get played 16 times. There was a lot of variance with this one. One other person had the same auction.
Here's the hand.
♠A led your mission, if you choose to accept it, Jim, is to make 3♣+1

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[Stephen Tu]

• By a passed hand, it's very rare to play 1nt as 100% forcing. Passing is fine with balanced minimums for the vast majority of 2/1 players.
• If unpassed hand, semi-forcing NT where you also pass balanced minimums has gained considerable popularity, but if you play it as forcing it's absolutely standard to bid 2♣ on 3523 shape. You'd also bid 2♣ on 2533 min or 4522 shape and min (< reverse strength). What to bid on 3532 there is differing opinion, some bid 2♦ (trying to minimize partner passing 2c in 4-2 fits), others bid 2♣ (so that 2♦ can guarantee 4).

As for the impossible 2♠ raise, there is a good rationale for it. The idea is that 1♥-1nt-2♣ has a very wide range in standard bidding; opener can have up to 18 points or so. Because 3♣, a GF jump shift, is supposed to be ~19+. So with unbalanced strongish hands, opener bids 2♣ very often, and counts on partner to keep the auction alive except with his very worst hands with club fit and heart misfit. But if responder wants to raise clubs on say a decent 8 count, there is a problem if he also wants to make the same bid on a 11/12 point hand; 3c has a too wide range of 8-12 and now opener with a moderate hand of around 14-15 doesn't know whether to continue or not. Thus the splitting of the raises into two ranges, 3♣ being the "courtesy raise" of ~8-9/bad 10, with 2♠ being stronger than this. 2♠ doesn't have a natural meaning since with < GF strength and spades 1♠ would have been bid over 1♥, or with GF strength would have started with either 2m or 1♠ depending on suit lengths.

[nige1]

pilowsky ' I was chatting with a partner of mine the other day and the question of what to bid in a 2/1 auction when you open 1♥ and your partner - a passed hand - responds 1NT and you have a 5332 shape. I know that it's definitely forcing for one round and with my 5332 (15.5%) shape I didn't want to repeat my hearts since that would show 6. So, in order to keep the bidding at the lowest possible level, I chose 3♣ even though I only had 3.I was a little surprised that GIB took that as an appropriate bid but was even more taken aback by North's response.2♠ ALERT "impossible spade -- 4+ ♣; 2-♥; 11- HCP; 11-12 total points; forcing to 3♣"Effectively, a transfer to 3♣. In the end, I'm not entirely sure why GIB felt it necessary to roll out this wonderful gadget and not just raise the clubs. North is a wily customer. It's a good thing I play with GIB a lot and carefully study the system notes so that I know about the impossible spade, I think there is a comprehensive description of its use on page 112.At least I'm 3.7 IMP's up.As you know, hands in BBO get played 16 times. There was a lot of variance with this one. One other person had the same auction.Here's the hand.♠A led your mission, if you choose to accept it, Jim, is to make 3♣+1'
+++++++++++++++++++++
An experienced self-kibitzer would kick off with a small ♠ but the lead of ♠A and another ♠ still puts declarer to the test. The winning line is ♠K, ♥QKA discarding a ♠. Then a small ♣ or ♦, losing just 3 aces. I doubt that I'd successfully walk that tight-rope.

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[thepossum]

The option I needed wasnt there. That is. I don't have a clue what is is, and why GiB occasionally bids it. I have read extensively and am none the wiser.

So I called it a useless gadget

Note. I think what annoys me most is the stupidity and meaninglessness of the name of the gadget

What actually is impossible? What is it telling me is impossible? A spade contract? A no trump contract? Anything else impossible?

As far as I can see in the only article that comes close to explaianing anything it means. "I've bid spades but because I previously bid 1NT you think its impossible. Well its not actually. I have a few and just bid them"

Couldn't a preferred name be the Unlikely spade. The Improbable Spade, along those lines

[pilowsky]

Turns out that like most things in Bridge, it comes with a quasi-amusing story.
Apparently, it was invented by Billy Miller and his partner who plotted it and bided their time until they sprung it on a disinterested opponent.
So unhappy where they at the opponents disinterest they have republished this same story multiple times in many places. Here is a link.
My only disappointment was that it isn't mentioned in the GIB system notes.

[thepossum]

I understand for some, knowing loads of (to me) unnecessary bidding gizmos is interesting and cool. I find GiB overloaded with them. A simple 3C club bid would have sufficed, and mysteriously other bidding systems seem to find that dibd without any trouble at all And another system got to, I believe a quite makeable 2NT etc - althought it didnt make that They are all just part scores give or take a trick so who cares

For me, the game is about something else other than having my head filled with over-technical systems and gizmos. We are all different

Apologies - the whole world has gone that way, seemingly every discipline has gone that way. I'm just a bit old fashioned and feel excessive technicality and/or technology ruins so many things

[smerriman]

thepossum, on 2020-November-17, 16:45, said:

Note. I think what annoys me most is the stupidity and meaninglessness of the name of the gadget

What actually is impossible? What is it telling me is impossible? A spade contract? A no trump contract? Anything else impossible?

Bidding 1NT says "I do not have 4 spades".

Therefore your next bid cannot mean "actually, I do have 4 spades".

It is 100% impossible (not unlikely, or improbable) that it shows spades. Thus the perfect name for the convention.

Instead, the bid shows something completely different - in this case, a maximum hand with good club support.

If you struggle with memory there's no need to include it in your partnership. But if you don't struggle with memory, there is 0 reason not to start using it, given it is so useful to separate good + bad club raises for the reasons Stephen Tu mentioned.

Honestly, it's actually one of the easiest conventions to remember, at least from opener's point of view; as soon as you hear it you know instantly it can't possibly be natural - if you held 4 spades as opener, you were disappointed to hear 1NT and discover there was no spade fit, so hearing it immediately 'shocks' you - so what else could it mean?

[pilowsky]

In the end, I quite liked it.
After all, over 1NT, 2♠ is a transfer to clubs, so it has a certain symmetry to it.

I like smerriman's mechanistic explanation.