[AL78]

There was a bit of discussion in the Acol thread about strong and weak NT and some advantages/disadvantages of 4/5CM. Here is what can happen when you play an anti-field system.

MPs:

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Made +1 for a bottom (declarer cashed the wrong diamond honor first). Two pairs found 3♥ our way making 9 or 10 tricks which I think is easier to find if North can open a weak 1NT and East doesn't fancy bidding at the two level. The third pair went three off in 2♠E.

[the hog]

" East doesn't fancy bidding at the two level." I doubt there would be many who would not bid over a wnt.

[AL78]

the hog, on 2023-April-14, 22:18, said:

" East doesn't fancy bidding at the two level." I doubt there would be many who would not bid over a wnt.

Easier if you are playing a two suited overcall that allows you to show diamonds and spades. One East did overcall 2♠ and went for -300 which illustrates the danger of making aggressive two level vulnerable overcalls on mediocre suits and a minimal hand.

[pescetom]

I'm not sure I see your point here. You missed 3♥ which could have been found and they had a sound overcall of 4♦ anyway, don't think the problem is in the choice of strong NT with or without a weak NT field.

[AL78]

pescetom, on 2023-April-15, 15:26, said:

You missed 3♥ which could have been found ...

How?

[the hog]

AL78, on 2023-April-15, 15:58, said:

How?

By bidding 3H over 3D.

[AL78]

the hog, on 2023-April-15, 16:19, said:

By bidding 3H over 3D.

Theoretically yes, but as sergeant Wilson would say, "Do you think that's wise" vulnerable with a five count and a ten high suit?

[pescetom]

AL78, on 2023-April-16, 04:12, said:

Theoretically yes, but as sergeant Wilson would say, "Do you think that's wise" vulnerable with a five count and a ten high suit?

It's hard to be objective seeing the board, but it looks reasonable to me: partner's bidding suggests he is more or less balanced and that with a known clubs fit and a void in their suit you can risk competing in your 6 card major.

[mycroft]

• It's aggressive, but I'm making a negative double of 1♠. It's not really going to help this auction, but still.
  
• 1NT-2♠ (spades and a minor, about opening values)-p-3♣ (p/c); p-3♦. I believe in sound overcalls of weak NTs, and this is a minimum, but you have to act sometimes. Now, I'm assuming that if partner passed 1♣-1♠, they're passing 1NT-2♠. Others might lebensohl into 3♥ and hope it isn't 200 or 500 into nothing; I, frankly, would bid 4♥ (I want to play it, hide the diamond void and protect the ♠K. I could bid 4♣ instead and let partner play it) and hope they have game, or might have game and guess wrong. 1NT-spades + m-4♥ - is west going to gamble that the minor is diamonds? Is west going to hit it and hope? She's not going to be happy leading, and even happier when both major Ks are scoring, never mind the diamond ruff...) But if your field is letting "some players" play 3♥ "for 9 or 10 tricks", then being that aggressive is a losing option - if it's 9, we're -100 or -200 into 140, if it's 10, we might not be able to double their "guess game" and be going 100 into 170. And if I've driven them into a nowhere-in-the-room 4♠ game that makes if partner doesn't find the diamond switch... And there's not much of a difference between 620 and 790, so goading them into doubling is all downside. So maybe not. I'd do it in my fields, though.
  
• after passing 1♠, I could bid 3♥ when they find their fit - more likely we have a fit too. Partner will not assume I found an Ace.

Yes, playing antifield like this (I usually get it the other way) means they'll get in a lot easier where others get 1NT-AP. But you get it back when you open 1NT and they're facing 1♣-1♠. And you get the benefits of getting to pass with weak openers and not having that "medium hand vs strong hand" problem. It balances out.

[pescetom]

Another useful check before letting them play a partial at MP is LoTT.
Here South has a probable 8 card fit in at least one round suit and can place the opponents with a 10+ card fit, so even at this vulnerability 3♥ can only cost if they leave in a double and have 10 tricks themselves.
It's not written in stone, but should give some courage when looking at those anemic hearts.