[nondas]

Although i have read quite a lot about the NT bids, i am still not certain, what is the strength shown by 2NT at the following cases

W N E S
1. 1♣ P 2NT P
2. 1♣ 1♠ 2NT P
3. 1♣ 2♥ 2NT P
4. 1♣ P 2♦ P
2NT
5. 1♣ 1♦ 1♠ 2NT

[Cyberyeti]

1-3 if you play this natural, 11-12 balanced, maybe 10 if your holding in opps suit improves with the overcall.
4 what is 2♦, what range of opening NT are you playing
5 you may get different answers on what that means, also may depend on the style of your simple overcalls

[ahydra]

For 1-4, as Cyberyeti said. Personally I play 2D in (4) as a weak jump, so 2NT is 18-19. I would play (5) as about 12-14.

ahydra

[RuflRabbit]

Agree with others on 2-5, but 1 is less straightforward. Modern 2/1 players will all or almost all play this as invitational, but in SAYC it's GF. IMO, GF is actually better, since you don't preempt your partner on what could turn out to be a slam hand. If you look at the history of 2/1's evolution, 1♣ - 2NT was originally GF in 2/1, and it changed not because invitational is better but to be consistent with 1♦ - 2NT, which had to be invitational to provide a bid for hands not suitable for any other call.

[nondas]

Cyberyeti, on 2019-September-23, 05:45, said:

1-3 if you play this natural, 11-12 balanced, maybe 10 if your holding in opps suit improves with the overcall.
4 what is 2♦, what range of opening NT are you playing
5 you may get different answers on what that means, also may depend on the style of your simple overcalls

The range of NT is 15-17. The 2clubs is a Jump Overcall

[rmnka447]

nondas, on 2019-September-23, 04:02, said:

Although i have read quite a lot about the NT bids, i am still not certain, what is the strength shown by 2NT at the following cases

W N E S
1. 1♣ P 2NT P

This is subject to partnership agreement. Originally, it was forcing to game, but now is played by most as invitational somewhere around 10-11, bad 12. It also pretty much denies a 4 card major.

Quote

2. 1♣ 1♠ 2NT P

Same as #1 but guarantees a ♠ stopper(s) and denies 4+ ♥. With ♥, you can make a negative double, then bid NT on the next round if partner doesn't have a ♥ fit.

Quote

3. 1♣ 2♥ 2NT P

Same as #1 but guarantees a ♥ stopper(s) and denies 4+ ♠. With ♠, you can make a negative double, then bid NT on the next round if partner doesn't have a ♠ fit.

[helene_t]

If you play Standard American, SEF or similar so that the 1♣ opening includes 12-14 balanced, then 1-3 are normally played as invitational opposite 12-14. With 10 you would give up on game and with 12 you would force to game, so this is basically 11 (subject to up/downgrades of course).

But some have different agreements.

4. depends on the meaning of 2♦. If 2♦ is strong then 2NT is 12-14 OR 18-19. Since you are in a GF already there's no rush to distinguish between the two. You will obviously invite slam later if you have 18-19.

5. is probably played as something artificial by more sophisticated partnerships. Maybe a diamond raise with a hearts feature? But if it is natural it will have to be quite strong, i.e. showing 22 points together with partner's minimum. So if you expect 8 points for an overcall, this should be 14-15.

[Zelandakh]

nondas, on 2019-September-23, 04:02, said:

Although i have read quite a lot about the NT bids, i am still not certain, what is the strength shown by 2NT at the following cases

W N E S
1. 1♣ P 2NT P
2. 1♣ 1♠ 2NT P
3. 1♣ 2♥ 2NT P
4. 1♣ P 2♦ P
2NT
5. 1♣ 1♦ 1♠ 2NT

1. There is no international standard for this. In Europe it is normal to play it as 10+-12 but in some parts of the UK Baron (16-18) is still used. In the USA the traditional meaning is 13-15 but the influence of approach-forcing methods like Acol has been strong and 10+-12 is at least as popular now with many not even realising that that is not part of SAYC.

2 and 3. I think almost everyone plays these as 10+-12, even if they use 13-15 or 16-18 for #1.

4. As Helene wrote, if 2♦ is a Strong Jump Shift then it is important to show shape without jumping around, so this just shows a balanced hand outside of NT range. As the auction is forcing you have time to differentiate between ranges later on.

5. The rule when responding in NT after partner makes a one level overcall is that you bid one level lower than after an opening, or, if you prefer, the bids show 3 points more. So a 2NT advance shows about 13-15.