[WGF_Flame]

In a game forcing position either after a jump or a 2/1 GF auction, what does bidding the 4th suit shows ?
is it natural ? semi natural ? artifitial like 4th suit forcing ?

1♥-1♠
3♣-3♦

1♠-2♦
2♥-3♣

[aguahombre]

IMO, once a game-force has been established, we should be looking for strain and the bids you gave as examples should be presumed semi-natural. The first one, however might be a 5-2-3-3 punt.

[aguahombre]

dupe

[gnasher]

I think they should be like FSF - no primary fit, and no stopper in the unbid suit. When you actually have length in the unbid suit, you also have a stopper in them, so you bid notrumps. In your examples:

1♥-1♠;3♣-3♦: a 5233 shape without a diamond stop. Being able to bid 3♦ with this means that 3♥ can show real preference and 3♠ can show real spades.

1♠-2♦;2♥-3♣ (playing 2/1 GF): a 2353 shape without a club stop. If 3♣ is natural, I don't know how you bid this hand.

I think there's a geographical divide about this. In North America, everyone seems to play them as natural. In England, it's normal to play them as artificial.

[helene_t]

Semi-natural is not really a great agreement imo. If it shows five or sometimes four, partner can raise it. If it shows four or sometimes three, it doesn't help partner much. If it shows a stopper, you might as well bid no-trumps yourself.

So I see four useful definitions:
- natural (5-card suit, or 4 when partner can hold four as well)
- artificial (waiting)
- anti-positional stopper
- half-stopper

In the first one, 3♦ is the cheapest bid so it shouldn't be too specific. It should cover most of the vague hands that can't bid anything else. This is particularly so if partner is known to make fake jump shifts so you need at least five clubs to raise it. If you are allowed to take preference to hearts on a doubleton, 3♦ will show a club raise.

On the second one, again it depends if you are allowed to take preference to spades on a doubleton. If so, you will always have a comfortable natural bid so you don't need an artificial 3♣. If not, you could think of a 2353 without a club stopper. I think that is too specific. When that hands come up you will have to rebid you diamonds or whatever you find most convenient. I would play 3♣ as natural here.

[Mbodell]

I had a disagreement with partner about this situation this weekend. The auction was (unopposed):

1♦-2♣
2♥-2♠

in a 2/1 with weak nt system. The 2♥ over 2♣ is natural showing 4 (or more) hearts and not necessarily extra values. The question was should 2♠ be natural looking for a spade fit or artificial likely looking for nt (if partner has spade stopped) or more information on shape/strength if not?

If you have 3=3=2=5 or 2=3=3=5 or 3=2=3=5 without a spade stop it is awkward if 2♠ is natural (although with the latter two you could maybe bid 3♦ since partner has 5 diamonds unless 4=4=4=1). If 2♠ is artificial it could be awkward if you have 6 clubs and 5 spades (although perhaps 2♠ followed by 3♠ could help show that).

When I bid it I had an anti-positional stopper (Ax) in a 2=3=2=6 hand, but the 6 card club suit was headed by the T so didn't look like a 6 card suit worth a rebid. Partner had 4=4=5=0 and we ended up playing our 4=2 spade fit in game after 3♠=3nt-(meant as to play/taken as non-serious since we'd bid and raised a major)-4♠. We were lucky and made 5 winning two imps against 3nt making 3.

[PhilKing]

WGF_Flame, on 2014-February-16, 08:20, said:

In a game forcing position either after a jump or a 2/1 GF auction, what does bidding the 4th suit shows ?
is it natural ? semi natural ? artifitial like 4th suit forcing ?

1♠-2♦
2♥-3♣

In the 2/1 auction, it is better to play 2♠ as artificial and waiting and 3♣ as a spade slam try (3♠ shows a spade raise with about 12 to a bad 15). 3♣ as 4th suit is not too bad - the situation is worse if our auction has started 1♠2♣2♥, since 3♦ makes it impossible for partner to give preference to clubs and still keep no trumps in the game.

Partner tentatively assumes an anti-positional stop but if we have a sequence such as:

1♠2♦
2♥2♠
2NT3♥

pard knows we are scratching around for a moysian fit, eg we get to 4♥ with:

♠AKxxx
♥KQTx
♦xx
♣Qx

♠Qx
♥AJx
♦AQxxx
♣xxx

With better spades, we can still get to Four Spades, and lacking either we take our chances in 3NT.

[Zelandakh]

Mbodell, on 2014-February-17, 03:35, said:

1♦-2♣
2♥-2♠ in a 2/1 with weak nt system.

It seems to me you either play 2♠ = nat, 2NT = bucket or 2♠ = bucket, 2NT = nat here. Whichever way you do it, bidding 3♠ over the natural rebid would be natural, presumably 4441 or 4450. Since the default rules of 2/1 follow an American standard, I would expect the first of these without discussion but (coming from a British background) the second makes more logical sense to me. The point Andy makes about the American-European divide is one I have noticed too and comes up a lot in various auctions of this type.

[P_Marlowe]

We play bidding the 4th suit still as artificial, and will call it FSF.
In the end, quite often you will need a marktime bid, to give you the
chance to differentiate between min and add. values.

And I also have a European background, I dont believe in looking and
finding a fit fit in the 4th bid suit.

With kind regards
Marlowe