[profhsg]

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

Thanks in advance.

[spotlight7]

profhsg, on 2018-October-21, 10:23, said:

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

Thanks in advance.

"Chicken Kaplan Sheinwold" used 12-14 NV and 15-17 vul.

I like KS with 12-14 NT as most players bid when using KS.

[pescetom]

profhsg, on 2018-October-21, 10:23, said:

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

Thanks in advance.

Various top level partnerships have played five card majors with 12-14 + 15-17 and even 10-12 + 14-16 or similar.

Maybe this topic belongs under Natural bidding systems rather than General BBO Discussion.

[The_Badger]

profhsg, on 2018-October-21, 10:23, said:

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

Thanks in advance.

It's quite common to play a 12-14 NT non-vulnerable or vulnerable in the UK, although pairs do play a 12-14 nv/15-17 v structure too. I actually like the pre-emptive value of opening 1NT with 12-14, and so does Fantunes (I have a feeling theirs is a 11-14 range, occasionally with a singleton too.) Occasionally you will get stung for a large penalty, but I feel there are many positives opening weak. As for incorporating it into a 2/1 GF structure, I can't see too many difficulties. If I remember correctly, Fantunes said a weak no-trump accounted for 28% of opening bids.

[barmar]

pescetom, on 2018-October-21, 13:23, said:

Various top level partnerships have played five card majors with 12-14 + 15-17 and even 10-12 + 14-16 or similar.

Indeed, I have many friends who play variable NT along with 2/1. There doesn't seem to be any particular reason why the basic system would impact this choice.

Quote

Maybe this topic belongs under Natural bidding systems rather than General BBO Discussion.

I've moved it to General Bridge Discussion. It doesn't seem to have anything to do with BBO.

[P_Marlowe]

profhsg, on 2018-October-21, 10:23, said:

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

Thanks in advance.

Disadvantage: System complexity, but if you can handle it, ...
We switched from strong to weak, we played NMF.
After some time we saw, that some NMF sequences rarely (if at all) showed up, we switched to a
wide range rebid NT structure as we replaced the NMF response structure.
Similar, if you open a weak NT, slam exploration tools after a weak NT opener are less relevant,
than after a strong NT opening, they still are valuable, but less so.
If you want to counter this, you will basically play two systems, which will become more and more
different.

With kind regards
Marlowe

[mikeh]

I played, for several years, a method involving 10-12 not vulnerable in 1st and 2nd, and 3rd at favourable, and 15-17 otherwise. We had some success, including a trip to the Bermuda Bowl. We dropped it towards the end of the partnership because we found that we lost out when we had a strong 1N and had to open 1m....all too often, RHO got to make a lead-directing overcall after something like 1C (P) 1H (1S) where had it gone 1N (P) 2C, RHO would have to pass. Also, as Rodwell said, in a strong club method, if you pass and then are defending, it helps a good declarer to know that you don't hold a balanced 10 count,

I later played a method with 11-14 1N in 1st and 2nd, with 15-17 in 3rd and 4th. I still play occasionally with that partner. I don't like 11-14, because imo the range is too broad.

I currently play 14-16 in all seats, and open almost all 11 counts, and am finding the system to be both fun and very playable (we play T-Walsh in response to 1C).

There's nothing inherently wrong with variable 1N. There can be memory issues, since it may make sense to play different treatments over the weak than the strong, especially if the variation is by seat. After all, in 3rd seat, you know that partner is limited by the initial pass. Also, while transfers are popular over both, we used to play a form of 2 way stayman in response to the weak, with some specialized treatments that were, imo, more powerful than transfers, but they impose significant additional memory load.

One problem is choice of the weak range. 12-14 was, and remains in many parts of the world, popular, but that means passing balanced 11 counts, which is against the modern trend to aggressive openings. Broadening the range to 11-14 leads to all kinds of range issues. If one has 11 as responder, passing 1N can lead to missed games when opener is max, yet responding can lead to uncomfortable 2N contracts on 11 opposite 11.

In one partnership that I played for one Team Trials, we played 11-13 for the weak variant, with 14-16 for the strong.

14-16 is a fine range, imo, but it does mean that one has to jump rebid 2N with 17-19, which can be uncomfortable when partner has responded on a 4-5 count (or less). Playing T-Walsh ameliorates the problem somewhat: 1C - 1red - 1N is 17-19.

Some players divide their 1N rebid hands, when 1N is a weak opening, into two ranges: if the weak is 10-12, open 1C and rebid 1N with all balanced 13-14 hands, and open 1D and rebid 1N with all 15-17 hands, as an example. I don't like that, since it becomes difficult to sort out minor fits for games or slams and, even worse on a frequency basis, for competitive bidding if they overcall in a major. Since I play imps (almost exclusively in terms of serious bridge) this is too much of a cost.

Anyway, experimenting is fun. In addition, even if you end up not liking variable notrump openers, playing them allows you to better understand their strengths and weaknesses, so that you will be better positioned when your opps do that.

[helene_t]

5-card majors is much easier to combine with a variable 1NT than 4-card majors is. The reason for this is that only minor suit openings are affected by the notrump range, assuming that opening 1NT with a 5M332 is not mandatory.

But you probably don't want to have a 1♦ opening which can include balanced 12-14 OR 15-17 depending on vulnerability. This is because, if the 1♦ opening contains 15-17 vulnerable,
1♦-(p)-1NT*
will be to play opposite 15-16 balanced, which means you have to bid 2♣ with 10 or a good 9. Hence, 2♣ can't be game forcing. But when 1♦ contains 12-14 balanced,
1♦-(p)-1NT*
is to play opposite 12-14 i.e. at least a decent 11, and you probably want to play it as GF then (you can respond 2NT or 3♣ with an 11-count).

This means that the 1♦-(p)-2♣ auction would be completely different at different vulnerabilities.

So you probably want to play an unbalanced diamond system with all balanced hands outside the notrump range opening 1♣. That way, only the 1♣ opening is affected by the notrump range.

There are still many things that work differently, though. For example:
1♠-1NT
2♦-3♦
Playing strong notrump, if the 1NT response is forcing, you can be left in a 4-3 fit. To avoid this, you either agree to play the 1NT response as nonforcing, or you agree that responder tries to avoid raising on 4, or you agree that opener rebids 2♣ on a doubleton and find a way to handle that. Playing weak notrump, you can avoid this problem by opening 1NT with specifically [5332].

1♣-2/3♣
Playing strong notrump with inverted minors, the 3♣ response is to play opposite 12-14 which means that 2♣ is a quite strong bid, and opener will force to game with just moderate extras. One problem with this is that it is not obvious if a 3NT rebid is 14 or 18/19. Playing weak notrump, the forcing raise can be weaker, and opener might need to distinguish between modest extras and GF.

1♣-1NT
Playing strong notrump, this is normally played as 8-10 and weaker hands have to fake a 1♦ response. Playing weak NT, this would make the 1NT response forcing except maybe opposite specifically [4414].

Negative doubles will have to be more aggressive when playing weak notrump as responder has to cater to opener having 15-17.

There are many other differences so it almost means that you have to develop two different systems. But as said, if playing unbalanced diamonds at least it is only the 1♣ opening that is affected.

[nullve]

mikeh, on 2018-October-23, 12:32, said:

14-16 is a fine range, imo, but it does mean that one has to jump rebid 2N with 17-19, which can be uncomfortable when partner has responded on a 4-5 count (or less). Playing T-Walsh ameliorates the problem somewhat: 1C - 1red - 1N is 17-19.

A trick mentioned by helene_t (here, although in a context with 15-17 NT) is to play

1♣-1N = INV+ opposite 17-19 BAL, < INV opposite 11-13 BAL, NAT

so that Responder always knows what to do when

1♣-1♠; 1N = BAL and either 11-13 or 17-19.

Problem solved!

[mikeh]

nullve, on 2018-October-23, 15:32, said:

A trick mentioned by helene_t (here, although in a context with 15-17 NT) is to play

1♣-1N = INV+ opposite 17-19 BAL, < INV opposite 11-13 BAL, NAT

so that Responder always knows what to do when

1♣-1♠; 1N = BAL and either 11-13 or 17-19.

Problem solved!

You're addressing an entirely different issue than the one I raised, which arises when we have had 1x 1y, where 1y is a suit, and opener has 17 hcp, in a 14-16 regime. He has to rebid 2N.

As for the situation about which you wrote....1C 1N, I currently play that as 8-11, being a bad 11, precisely because if opener has a balanced minimum hand, he knows not to bid over 1N. Game is out of reach, when opener is limited to 13.

We also play 1m 2H as a balanced (good)11 to (not good) 13, which allows us to play 2N from either side or, of course, 3N from either side, while also, through artificial bids, find various suit fits (including 5-3 majors when opener is 6-5).

[rmnka447]

I've played Kaplan-Sheinwold (11+-14 NT with 2/1 and 5 card majors) with my favorite partner for a long time with some success.

If there's a problem with strong NT type hands when playing weak NTs, I think part of it comes from most people not adapting their minor openings bidding to reflect the changed population of hands that results. The change in balanced hands present when 1 of a minor is opened profoundly changes the character of minor openers -- approximately 65% of minor openers are 15+ when playing weak NTs versus about 25% when playing strong NTs. Kaplan-Sheinwold addresses this by changing the meaning of many simple bidding sequences. For example, a simple raise by opener of responder's major is redefined as showing 15-17 value and 4 trump. Yep, there is a question of what to do with a minimum minor opener with a fit for responder's major. The answer is to raise anyhow and accept the consequences of responder expecting more. However, this doesn't come up very frequently. Since the minimum opener must be unbalanced, it may be with distribution that the hand is pretty close to 15 value anyhow.

Originally, a bidding sequence of 1 m - 1 ♥ - 1 ♠ could be made on any 15+ hand with 4 ♠. But eventually, several problems developed with this approach. The major one was wrongsiding NT contracts when opener held the strong NT hand. Also, some follow up bidding sequences made it difficult for responder to know if opener held a real minor suit or not. So most K-S players moved to just rebidding 1 NT with the strong NT hand. To avoid losing a potential ♠ fit in these situations, NMF emerged as an answer. This was way back in the 1970s. Also, this meant that after 1 m- 1 ♥ - 1 ♠ opener had an unbalanced hand.

With the revised minor opening bidding, Kaplan-Sheinwold has proved to be very effective. My sense is that we've been able on a fairly consistent basis to be more accurate in bidding minor suit games (vs. NT) and slams. This is off set by occasional wrong siding of major suit contracts versus strong NTers. And over a weak NT sometimes playing 1 NT when 2 of a major on a 4-4 fit is preferable.

Pay your money, take your choice.

[Cthulhu D]

mikeh, on 2018-October-23, 12:32, said:

In one partnership that I played for one Team Trials, we played 11-13 for the weak variant, with 14-16 for the strong.14-16 is a fine range, imo, but it does mean that one has to jump rebid 2N with 17-19, which can be uncomfortable when partner has responded on a 4-5 count (or less). Playing T-Walsh ameliorates the problem somewhat: 1C - 1red - 1N is 17-19.

We played this for a while (11-13 when it seemed good, 14-16 rest of the time) in a 5 card major, short club, unbalanced diamond context.

We tossed it because it adds a lot of complexity - in auctions you don't expect. Your support doubles work differently depending on what the vulnerability is. We'd decided 5332 hands are 1NT hands to improve the quality of other constructive auctions, so it's felt there. It obviously has a huge impact on your minor suit openers (though for us that's 1C). It changes how you want to play transfer walsh.

It's very tough, what feels like it should be a minor change has ripple effects through the rest of your system in constructive and competitive auctions that is hard to design for remember.

If you can handle that memory load of running two cards, I suspect it's a winner. We make enough mistakes running one card and so have the 14-16 NT range with T-walsh opening all 11 counts approach and think that's the best solution for us.

[akwoo]

I have played 12-14 1N openings in a 2/1-context, and it's my preferred system.

Variable is a bit tricky to play. Let's say it goes 1C-(2H) to you and you hold ♠Axxx ♥xx ♦Jxxx ♣Kxx

If you're playing 12-14 1N, it's a pretty safe negative double. You almost always either have a 9 card fit, two 8 card fits, or at least 23HCP between you. Playing 15-17 1N, your partner holds a flat 13 count a fair amount of the time, and a negative double is a lot riskier.

When you're switching all the time, are you going to get this right? I know when I've been playing 12-14 with some partner regularly and switch to 15-17 for a session, my 12-14 competitive instincts will get me in trouble on some hand.

[pescetom]

This topic has convinced me that a variable 1NT opening is a minefield for all but the most dedicated of partnerships.
It also got me even more interested in trying 14-16

[helene_t]

pescetom, on 2018-October-24, 15:36, said:

This topic has convinced me that a variable 1NT opening is a minefield for all but the most dedicated of partnerships.

Yes this is certainly true.

I think those who play variable notrump can roughly be divided into five groups:

- 1960-style Acol players for whom the 1NT opening isn't really part of the system because they are allowed to avoid 1NT openings for all kind of reasons, for example because you have only aces and want partner to declare. In that style, the 1NT rebid is 12-16 and 2nt is 17-18, regardless of what a 1nt opening would have meant.
- Simple-Acol players who haven't discussed the subtle details of inverted minors, negative doubles, check-back, light 3rd seat openings etc etc anyway so it doesn't matter that those discussions would have been affected
- Young Dutch Kamikaze pilots who open a 9-12 1nt in 1st seat at favorable. They mostly play teams so at favorable it's a good deal to mess up their own bidding system as long as they mess up opps' system also
- Players of advanced natural systems who play 12-14 in 1st/2nd and 14-16 in 3rd/4th. Their systems are completely different opposite a passed hand anyway so changing the notrump range doesn't make it more complex.
- Strong-club players for whom only the 1♦ opening is affected by the notrump range, and the fact that it is limited makes it easier to play so the complexities of the variable notrump are not so bad. Besides, modern strong-club players are not afraid of 200 pages of system notes.

[Cthulhu D]

pescetom, on 2018-October-24, 15:36, said:

This topic has convinced me that a variable 1NT opening is a minefield for all but the most dedicated of partnerships.
It also got me even more interested in trying 14-16

I think if you can manage the 17-19 rebid, 14-16 is significantly better than 15-17, particularly if you're already playing 14+-17 1NT.

This depends on some big bidding theory assumptions, specifically:

Opening light in a minor or NT is good, opening light in a major is good in the first seat.
In teams when one team opens 1NT and the other team opens 1C, the 1NT opener is better particular the weaker the 1NT opener is.

These assumptions may not be true though.

[pescetom]

Cthulhu D, on 2018-October-24, 16:45, said:

I think if you can manage the 17-19 rebid, 14-16 is significantly better than 15-17, particularly if you're already playing 14+-17 1NT.

Do you also drop 2NT to 19-20?
One of the things I like about our current 15-17 and 20-21 compared to systems played previously is the precision in identifying the HCP of strong hands, I wouldn't be comfortable going back to wider ranges (many people here play 15-17 and 21-23). We play Kokish so can handle several steps above basic 2NT.

[nige1]

profhsg, on 2018-October-21, 10:23, said:

I've always liked the Acol variant of having a variable 1NT opening of 12-14 not vulnerable and 15-17 vulnerable. Could such an approach be incorporated into a five card major 2 over 1 game forcing system? Advantages, disadvantages, thoughts?

spotlight7, on 2018-October-21, 12:32, said:

"Chicken Kaplan Sheinwold" used 12-14 NV and 15-17 vul. I like KS with 12-14 NT as most players bid when using KS.

Cthulhu D, on 2018-October-23, 16:24, said:

We played this for a while (11-13 when it seemed good, 14-16 rest of the time) in a 5 card major, short club, unbalanced diamond context.

When non-vul,
Acol or K-S, with 12-14 1N seems reasonable, as spotlight7 suggests.


When vul, 2/1 is OK but you could experiment with...
Short ♣, unbalanced ♦, 14-16 1N, and 19-20 2N are OK, as Cthulhu D suggests.
A 2N rebid can show 17-18.
Alternatively, you can try a modified Gazzilli 2♣ rebid after all 1-openers.
Also worth considering are transfer responses to 1♣.

[Cthulhu D]

pescetom, on 2018-October-25, 11:09, said:

Do you also drop 2NT to 19-20?
One of the things I like about our current 15-17 and 20-21 compared to systems played previously is the precision in identifying the HCP of strong hands, I wouldn't be comfortable going back to wider ranges (many people here play 15-17 and 21-23). We play Kokish so can handle several steps above basic 2NT.

No - you have invites available after 1C-1red-1NT so you can have a broader range of NT and still manage with precision. So our ladder is

11-13 1C, accepting the transfer
14-16 1NT
17-19 1C, rebidding 1NT
20-21 2NT
22+ 2C using Kokish.

[nige1]

Agree with Cthulhu D that an advantage of short ♣ with transfer responses is that accepting the transfer can be a dustbin rebid, releasing a 1N rebid to show 17-19.
If you play Kokish, you might also consider adjusting notrump ranges.

• 2N = 22-23
• 2♣ - 2♦ - 2N = 24+
• 2♣ - 2♦ - 2♥ - 2♠ - 2N = 20-21

This means that with poor responding hands, you can sometimes stop in a making 3-level contract by breaking the Kokish puppet i.e.
After 2♣ - 2♦ - 2♥ -

• 2♠ = Normal puppet
• 2N = UNT Weak 5+ 5+ m e.g. ♠ x ♥ x x ♦ J x x x x ♣ x x x x x
• 3any = NAT Weak 6+ suit e.g. ♠ x ♥ x x ♦ J x x x x x x ♣ x x x