[TimG]

At IMPs, white vs white. The auction starts:

P - 1♥ - P - 2♥
2N - 3♥ - 4♦ - 4♥

Do you have any agreements about whether 4D is merely competitive or invites intervenor to sac?

When partner has preempted, Robson-Segal suggest using 3N as a way to the 4-level which suggests a sac and a direct 4-level action as blocking and not inviting partner's cooperation. I wonder if this idea might be extended to the auction in question (and perhaps other unusual 2NT auctions).

Perhaps this auction makes more sense:

1♥ - P - 2♥ - 3♦
DBL - 3N/4♦

where double is a game try.

Tim

[cherdanno]

On the first auction, the 2N bidder can still have a wide range of shapes. So any sort of raise should allow him to go one level higher if he has the right shape for it.

[Phil]

By a passed hand you have a 3N call available to say, "if they bid 4♥, take the save if you like your hand fr offense". 4♦ implies that you will know what to do over 4♥.

Similarly, 4N and 5♦ convey a cooperative / stfu attitude about the hand.

A double of 4♥ by the 2N bidder can also be used in a cooperative setting to mean, "I really want to bid 5♦ but I'm doubling JIC".

[Jlall]

Why would we ever expect them to bid 4H on this auction?

[aguahombre]

Jlall, on Dec 13 2009, 06:38 PM, said:

Why would we ever expect them to bid 4H on this auction?

They do it at the club, all the time. but in the real world, no.

[TimG]

Jlall, on Dec 13 2009, 08:38 PM, said:

Why would we ever expect them to bid 4H on this auction?

That's why I put in the second auction, so that there would be a reasonable expectation that they would bid 4♥ on their own.

Funny thing is that I bid 5♦ on the first auction, went for 300 and saved some MPs in the process. I don't think bidding 5♦ was reasonable, sensible, defensible, etc. even though it worked out. But, it did get me to thinking about these sorts of auctions.

[gnasher]

Jlall, on Dec 14 2009, 02:38 AM, said:

Why would we ever expect them to bid 4H on this auction?

Someone's hand might be improved by the auction. Or they might do this calculation:

Bidding 4♥ instead of playing 3♥ gains 6 or loses 5, so the odds required were 45%.
Bidding 4♥ instead of defending 4♦ for one down gains 9 or loses 3, so if they bid 4♦ at the other table the odds required are now 25%.

Perhaps a better argument would be: if we're so scared that they'll make 4♥ that we're thinking of preparing a sacrifice, why would I do anything to encourage them to bid it? Or maybe that's what you meant anyway.

[jdonn]

If I was about to bid a game believing my odds of success were between 25% and 45%, I sure wouldn't want to bid in a way that tells my opponents that!

Anyway I play nothing artificial here. If I want to save opposite no extra offense I save. If the 2NT bidder has extra offense he is always welcome to bid more anyway.

[dake50]

Why would partner ever 2N to help opponents' evaluate ->4h on promote 'right' stuff. He must think one/both minors have a future. Do I agree? 4D =Yes. Then 5D next is reasonable.