Weak 2NT

[1eyedjack]

One peculiarity of the weak 2N opener (contrasted with weak 1N) is that 2N doubled is game, where 1N doubled is not. I know of a number of occasions in which I have doubled 1N fully expecting it to score 180 on a proportion of hands. Hopefully that proportion is low enough to justify the double, and if they redouble for blood we might readjust our priorities mid-auction. They don't have to redouble 2N to get the game bonus so the pressure on our side is correspondingly higher. How that factor in conjunction with the increased level, affects the cut-off at which it is right to make a penalty-suggestive double (in either seat) against 2N contrasted with 1N is an interesting question on which I would be interested in the opinions of others.

[helene_t]

Interesting point, Jack.

 

I think at matchpoints you are still heading for a bad score if you double a making 1NT. If it makes +3 you are still worse off than those who defend 3NT+1. So the "stripe tail ape" double of 1NT is only rewarded when they make exactly 9 tricks.

 

At IMPs it is a different story since the occasional 2NTx= will weigh more.

[Gerben42]

One peculiarity of the weak 2N opener (contrasted with weak 1N) is that 2N doubled is game, where 1N doubled is not.

 

Good point. In our standard runout sequence vs 1NT, 1NTxx is a possible contract. Since this is not needed after 2NT, that's quite useful.

[Gerben42]

Had some more hands with a weak 2NT. On two of them, we bid the normal game. On a third we bid the normal slam. On the last one, opps missed a vuln. game but it was due to own passivity. After 2NT p p, 4th seat passed a 12-count with 6 decent ♥...

 

Never mind that. Anyway, it seems that it doesn't have much of an effect on most deals.

[dellache]

Here is a simple NON-OPTIMAL working algortihm for oppos, at any vul (you are w) :

- in #2 POS : DBL with any 13+HCP or 6 Tricks, pard never pulls.

- same in #4 POS if responder passed.

- DBL any rescue at the 3 level with an "average+" (what is this ?) hand regarding trumps and HCP (actually you can also have a simple algorithm to know when to double. Here I used a linear fonction of trumps and HCP for both #2 and #4, with 2 different thresholds -- for those who care F=HCP+3T where T is the number of trumps).

- you don't have the right to bid anything else (stupid new game).

 

Doing this, you get those aproximate results using DD-evaluation (750000 boards) :

- 35% of the boards, oppos DBL you, and you lose app. 2.5 imps on those boards on average ( I supposed you even make it XX if you scored overtricks, and that your teammates will call and make any DD-games with the oppos cards !)

- 35% (edit) of the boards, oppos stay quite, and responder has 11+HCP. You cannot expect to gain too much there :rolleyes:

- 5% of the boards, you play 2NT they miss a DD making game (probably also a pain to bid when nobody has more than 12HCP and you opened 1NT anyway).

- 25% nothing like this happens, so I don't know.

 

The fact that the sim is DD is in fact questionable as I suspect the opening lead will be very important. Anyway, the margin looks quite high. So this time, I did only very few single dummy checks. I don't think you'll get good scores in the long distance playing this convention.

 

Of course if your oppos go crazy, you might get avg+.

 

(I remember having designed such defenses against a pair who was playing 2♠ 0-7 any shape when NV. We clobbered them).