[Liversidge]

We play Acol (4 card majors), Jacoby 2NT, opener simple No Trump rebid = 15-17
I have come across a hand where we failed to find a 6NT slam with 34 combined HCP. . I ran it through Jack, set to our conventions, and it failed to find it too.
North: ♠9864 ♥A2 ♦AK875 ♣AQ
South: ♠AQ ♥KQ83 ♦QT6 ♣KJ62

Jack's advice:

North South
1♦ 1♥
1♠ 2♣* 4th suit GF
2NT 3NT
P
As North's 2NT can be weak (forced to bid), should he have bid 3NT to show 15+, so South can then bid 4NT quantitative? When I changed North's third bid to 3NT Jack passed.

[FelicityR]

Since you are using Acol there's no harm bidding 2♦ after 2♣. The 4th suit has set up the game force. Rebidding 2NT or 3NT here will always present problems with borderline hands. When partner supports ♦s, you have a great chance of finding 6♦ or even 6NT.

[gordontd]

 FelicityR, on 2018-July-18, 03:45, said:

Since you are using Acol there's no harm bidding 2♦ after 2♣. The 4th suit has set up the game force. Rebidding 2NT or 3NT here will always present problems with borderline hands. When partner supports ♦s, you have a great chance of finding 6♦ or even 6NT.

3D after 2C should show extras. Alternatively, in the given auction you should be safe to raise 3NT to 4NT.

[Cyberyeti]

 Liversidge, on 2018-July-18, 03:22, said:

We play Acol (4 card majors), Jacoby 2NT, opener simple No Trump rebid = 15-17
I have come across a hand where we failed to find a 6NT slam with 34 combined HCP. . I ran it through Jack, set to our conventions, and it failed to find it too.
North: ♠9864 ♥A2 ♦AK875 ♣AQ
South: ♠AQ ♥KQ83 ♦QT6 ♣KJ62

Jack's advice:

North South
1♦ 1♥
1♠ 2♣* 4th suit GF
2NT 3NT
P
As North's 2NT can be weak (forced to bid), should he have bid 3NT to show 15+, so South can then bid 4NT quantitative? When I changed North's third bid to 3NT Jack passed.

Couple of questions:

Does 1♦-1♥-1♠ show 5-4 unless 4144 ? If it doesn't show 5♦ then 2♦ is better than 2N.
Do you play a raise of the 4th suit as natural or artificial here ? it can be useful as "5th suit forcing", you have 2 hearts, 4 spades and 5 diamonds, if partner bids any of these suits now you're happy, but it causes issues where you do have the rare 4144/4054 shapes.

I would bid 4N on the end of this auction as N, partner should have 13 ish, he should be raising if a king better than that which seems about right.

[hrothgar]

I play a pretty sound reverse style

I would rebid 2!S over 1!H.

If you can't stand reversing on such a weak suit, then rebid 2NT

[The_Badger]

I'll let my other bridge friends answer this comprehensively, but I'm sure with the 2/1 system there's a two-way 2NT rebid either showing a minimum hand or a hand in the range 17-18 or 18-19*. Whether you can play it after 4th suit forcing I really don't know. As other commentators have said raising 3NT to 4NT effectively shows extras, and that would not confuse partner if there was an agreement as above*

[The_Badger]

 hrothgar, on 2018-July-18, 04:28, said:

I play a pretty sound reverse style

I would rebid 2!S over 1!H.

If you can't stand reversing on such a weak suit, then rebid 2NT

It'll probably stop the opponents taking the first five tricks in a 3NT contract reversing with a weak suit. The hand is technically strong enough for a reverse, but I do like my second suit to have some substance, perhaps a 10 as opposed to 98

[gordontd]

 hrothgar, on 2018-July-18, 04:28, said:

I play a pretty sound reverse style

I would rebid 2!S over 1!H.

If you can't stand reversing on such a weak suit, then rebid 2NT

2S is not a reverse and the hand is not strong enough for a game-forcing jump-shift rebid.

[Tramticket]

The auction isn't silly - you just stopped too early! North needs to show extras by bidding on over 3NT. What would 3NT over 2♣ show? If this shows extras, then it might be a better bid - then South needs to bid on.

[Cyberyeti]

 gordontd, on 2018-July-18, 05:27, said:

2S is not a reverse and the hand is not strong enough for a game-forcing jump-shift rebid.

I think a lot of Americans play it more like a reverse and not GF judging by what they make the bid on.

[neilkaz]

 Cyberyeti, on 2018-July-18, 07:26, said:

I think a lot of Americans play it more like a reverse and not GF judging by what they make the bid on.

Not this American. Opener's Jump Shift is GF for me.

[Cyberyeti]

 neilkaz, on 2018-July-18, 10:08, said:

Not this American. Opener's Jump Shift is GF for me.

Fair enough, I see a lot of random 5431/5422 18 counts being bid like this on these forums

[pescetom]

Outside the ACOL/SAYC world a lot of us would open North's hand 1NT, after which almost any method (Quantitative, Gerber, guesswork) leads to 6NT.

[Winstonm]

I don't play Acol, so I don't know what 2N and 3N should show in these sequences. Even then, someone somewhere in this auction needs to show extra strength, and I like Felicity's approach of simply bidding 2D in an already game-forcing auction.

[Winstonm]

 neilkaz, on 2018-July-18, 10:08, said:

Not this American. Opener's Jump Shift is GF for me.

I know this doesn't pertain to the OP, but it does open the question of whether or not opener's 1H or 1S rebid should be forcing or passable. My old friend and partner Bob Holmes used to assure me that expert standard was to play these bids as 1-round forces. That was not my understanding, but I didn't quibble.

[bravejason]

It sounds like Jack was seeing North as a minimum (2NT) or slightly better than minimum hand (3NT) that is a misfit for South. Hence the passing of 3NT.

I’d probably jump rebid NT as North. I know you have doubleton pair, but they are strong and South has hearts. It’d work out fine in this case, but there is always the chance partner has the same doubleton(s) and down you go.

[ahydra]

North should rebid 3NT over 2C to show the extra values. (His range is 11-18 at that point, because he only rebid 1S. Note that 2S is not a reverse, but a GF jump shift promising a very good 18 or better. The third-round 2NT could be the same hand without the DA.)

Then, knowing North has ~15-18, South has a quantitative invite - if he doesn't feel like just blasting 6NT directly - and North an easy accept. For a more scientific approach South could set diamonds as trumps, since North has promised 5 (unless he could be 4144, I open 1C with that but some open 1D).

ahydra

[wank]

you may know the concept of fast arrival: that once you're in a game force jumping to game shows a minimum, on the basis that with a good hand you would take it slow to investigate slam. i know many good players who erroneously think this applies in no-trumps too; it doesn't. jumps in no-trumps always show extras. over 2C 3NT would be an option with that hand then, in purely HCP terms.

this hand doesn't want to commit to no-trumps though. with no spade stop, despite having bid them, you might find yourself going off in 3NT with slam cold when partner naively passes with e.g x kqjxx qxx kjxx

the traditional bid with this shape over 2C is 2H which is conveniently low - there's no rush and your hand is as playable in every suit as it could be after starting 1D-1H-1S . You may think 2H shows 3, but unless you're French, it's normal to raise immediately on 3 card heart and a minimum with an unbalanced hand (like 4351), ignoring the spades (partner can bid them himself if he's got enough to invite/force game) and with 4351 and extra values, you would rebid 1S and jump to 3H now (having shown your shape and values so nicely the space consumption isn't so important). if you're 4351(4360) with extras and partner makes a weak 2nd bid, you just bid hearts at the 2 level, e.g. 1D-1h-1s-1nt-2h = extras 4351/4360.

[ahydra]

 wank, on 2018-July-18, 20:15, said:

You may think 2H shows 3, but unless you're French, it's normal to raise immediately on 3 card heart and a minimum with an unbalanced hand (like 4351), ignoring the spades (partner can bid them himself if he's got enough to invite/force game) and with 4351 and extra values, you would rebid 1S and jump to 3H now (having shown your shape and values so nicely the space consumption isn't so important).

I'm not sure the N/B forum is the best place to recommend these kinds of advanced treatments. Raising on 3 brings a whole bunch of system changes with it, such as the 4SF change you mentioned, and also how to find a 4-4 spade fit and distinguish between the 3- and 4-card raise with e.g. spiral raises. Personally, though I am in no way French, I hate raising on 3 if I can avoid it. 4-4 fits often play better than 5-3s, and you can always show secondary support later.

OTOH, I also quite hate the idea of eating all the room with a jump to 3NT over 4SF just to show extras. Despite the fact it's fairly standard, it seems odd to have this as an exception to the fast arrival principle applied in almost every other GF auction. Perhaps 2NT is playable as simply "yes, I have a club stop", nothing about strength? This allows responder to clarify his range and reason for 4SF'ing first (straight 3NT with a minimum GF, something else with more), and if opener's still interested he can continue, for example by raising to 4NT. So here it might go ...2C; 2NT-3D and opener isn't stopping short of slam now.

ahydra

[wank]

 ahydra, on 2018-July-18, 20:56, said:

I'm not sure the N/B forum is the best place to recommend these kinds of advanced treatments. Raising on 3 brings a whole bunch of system changes with it, such as the 4SF change you mentioned, and also how to find a 4-4 spade fit and distinguish between the 3- and 4-card raise with e.g. spiral raises. Personally, though I am in no way French, I hate raising on 3 if I can avoid it. 4-4 fits often play better than 5-3s, and you can always show secondary support later.

OTOH, I also quite hate the idea of eating all the room with a jump to 3NT over 4SF just to show extras. Despite the fact it's fairly standard, it seems odd to have this as an exception to the fast arrival principle applied in almost every other GF auction. Perhaps 2NT is playable as simply "yes, I have a club stop", nothing about strength? This allows responder to clarify his range and reason for 4SF'ing first (straight 3NT with a minimum GF, something else with more), and if opener's still interested he can continue, for example by raising to 4NT. So here it might go ...2C; 2NT-3D and opener isn't stopping short of slam now.

ahydra

liversidge seems like an aspirational variety of n/b. in general i think people who bother to post on the forum to get answers are sufficiently keen that they'll be rapid improvers, to whom one should talk up, but yes there's obviously a balance to be struck. UK bidding teaching and perforce knowledge is terrible. I think it's a grossly overrated convention, but in Croatia, where I live, more than half of the room at the bridge club plays gazilli.

as for what you wrote about 2NT range non-specific, that would reduce the number of ranges you can show from 3 to 2. by playing jumps as extras you have 3 ranges: 1) jump = extras but limited, i.e. something like 15-bad 17 (yes this hand might well be too good for it) 2) min bid then raise later beyond game = max extras, something like good 17-bad 19 (assuming 1S was nf) 3) min bid then pass = minimum. by always bidding 2NT then deciding whether to raise later or not, you would just have 2.