[navit]

I know that if we play jacoby transfers after N the bidding is

1 NT pass 2 H OR 2 D PASS 2S OR 2H


What happens if the 3 seater overcalls? How is the transfer completed?

Thanks

[han]

Let's first say that the bidding goes 1NT-p-2D-(Dbl)-??

Without discussion I would assume that completing the transfer shows 3-card support, passing denies that. Redouble is a suggestion to play 2DXX. You can play superaccepts as usual. There are other more complicated agreements possible but this one is most standard.

Now let's say it goes 1NT-p-2D-(2S).

To complete the transfer, opener would have to go to the 3-level. Responder could have a 0-count, so opener shouldn't do this on many hands with 3-card support, and certainly never without 3-card support.

I play the double as penalty here, and I would assume this without discussion. But you'd better have a lot of tricks in your hand, don't count on partner to help!

[awm]

Usually 1NT-Pass-2♦-Bid-3♥ should show four-card support. This probably shouldn't show a maximum hand -- it's basically a "law of total tricks" competitive bid on the guaranteed nine-card fit. If you have bids available you can use these as super-accepts (for example 1NT-Pass-2♦-2♠-2NT/3♣/3♦). In any case it's never right to bid without a fit (except perhaps to make a rare penalty double keeping in mind partner may have nothing). One mistake I see frequently is to bid 2NT "natural" without a fit (1NT-Pass-2♦-Pass-2NT or 1NT-Pass-2♦-2♠-2NT) -- partner could have a zero-count for the transfer and you don't want to play 2NT opposite that!

Another useful rule is the meaning of double. If opener passes and responder doubles (1NT-Pass-2♦-3♣-Pass-Pass-Double) then this simply shows values and denies freak shape (usually not 5-5 in two suits, not 6+ cards in the suit transferred to). Usually opener will leave this in if holding doubleton in the suit transferred to, or with a strong holding in the overcaller's suit. Otherwise opener can complete the transfer (now at the three or four level) with three-card support.

[barmar]

Another key feature of Justin's hand is that his ♠ are short and weak, so he doesn't want to defend 2♠. Swap the ♠ and ♣ and I suspect he wouldn't be so keen on bidding 3♥ (I suspect he'd do it anyway, but he wouldn't be as sure about it).