29 July 2011

Improving Jacoby 2NT

Like a lot of people I've played the convention:
When partner opens one major a bid of two no trumps shows four card trump support and is forcing to game.
I've also played it in a more stepwise fashion so 1 - 2NT is Jacoby and 1 - 3 the same. Whichever way around you do it we're talking about the same convention.

The question is; what next? The way I learnt it was a little bit like this (assume the auction 1 - 2NT):
3/3/3Shortage with extras
315 - 17 balanced
3NT18 - 19 balanced
4/4/4Void with extras

On the surface this seems like a good idea. Fast arrival tells us that it's good to bid game immediately when we have no interest in anything further. There's two problems though, firstly what does "extras" actually mean and secondly 4 hamstrings a strong responder. Consider the following hand from the NZ pairs semi-final:

A J 4 3 2
A 8 3
K T 8 3
K 9 8 5
K Q J 2
Q 8
A 9 5

Playing the above structure the West hand opened 1 and East responded 2NT. What is your call?

12 points therefore minimum? But you have 2 Aces, a King and a singleton. Opening bids don't need to be nearly this suitable for slam. If you bid 4 partner is shut out.

So our hero West bid 3 to show his singleton and controls and East drove to slam. Even if you find the Q 12 tricks are impossible on a diamond lead. When both go bad you'll have to admit you should never have broken cover in the first place.

Here's what I've learned :
3Even so, what's your shortage?
OthersResponder shortages stepwise
3Extras but no shortage
3Start the cue bidding!
OthersResponder shortages stepwise
3//NTOpener shortages stepwise (extras!)
4//5 card suits no extras

The advantage is subtle. In fact the number of ranges you can immediately show maybe isn't as good. The big benefit is that after you show minimum a moderately interested partner can make further tries below game. That means that you can happily show min on the hand above safe in the knowledge that if partner wants to know more all they need do is ask.

As for showing extras just because you've got all your points in Aces. There's another convention for solving the Aces problem. Blackwood. It works really well.


  1. That's definitely a good scheme, even allowing 2NT to become a limit or better raise (though it is annoying giving away info when opener is better than minimum).

    East should definitely change their tack after hearing about diamond shortage on the hand. Just counting tricks shows that slam in hearts will normally be better than slam in spades.

  2. 6H is playable at least. Interesting that after finding a 9 card major fit the best contract is in the 7 card fit on the side. Bidding is a strange thing.

    The other nice thing about this structure is you can play it over your weak 2H/2S openings. Though the auction 2S - 2NT - 3C - 3S is now a sign off rather than a diamond shortage.