[mikl_plkcc]

I am playing some games and the system there says system on after doubling a 1NT, e.g. (1NT) - X (penalty) - (/) - 2♥ is transfer to ♠. Is this convention commonplace?

I think I have also seen system on after a 2NT rebid (not after a strong 2♣ opening) but I can't remember the exact sequence. How does it work?

[jdiana]

1. We played systems on after X. I think that is pretty standard. After 2♣, X was Stayman but otherwise, systems were on there also. (If 2♣ shows both majors, then X is no longer Stayman. In that case, we used our simplified lebensohl bids.) I think that's also fairly common but I'm not sure.

2. After 1x-1y-2NT (18-19 HCP), if that's what you're referring to, we played systems off.

[mycroft]

If you mean "systems on after they double our 1NT", that's an okay decision that many (playing strong NT at least) play. Why give up all your hard-learned system just because they said something you can ignore, especially because many if not most pairs play a conventional double?

If you mean "systems on after we double their 1NT" (for penalty), run. Do not even look. First, the best penalty doubles are where you can lead your fourth-best J of 7, or the similar "one-loser suit with an ace". If this gets pulled, I know where to play and you don't. Second, you should not be planning on pulling 1NTx (enough to have lots of system against it). You pull in two situations: "I'm too weak to sit for this, and I have a long suit that will score many more tricks as trump than on defence" and "I don't think we are getting this enough to beat our likely game, when we can place all the outstanding high cards". The first means you want to be able to play 2♣, not 3♣, if that's the suit; the second is so rare you can assign 2NT to it and "guess" your way to game.

Plus, I guarantee that at least half the time, one of you will forget, or think you're playing it when partner is saner, and that invariably leads either to a poor score or a director-assigned (poor) score.

[pescetom]

1. I agree that systems on after their penalty X is common, as is X of their 2♣ being Stayman (although I don't think that is great when 2♣ is Landy, as it almost always is over here).

2. After 1X - 1Y; 2NT some of our old timers play systems on, but I don't think it is common (or very good).
After preparatory sequences to NT like 1♦(5+) - 1M(3+); 1NT(18-19) or 2♦(Multi) - 2M(pass/correct); 2NT(20-21) then systems are obviously on.

[jdiana]

mycroft, on 2025-February-14, 08:06, said:

If you mean "systems on after they double our 1NT", that's an okay decision that many (playing strong NT at least) play. Why give up all your hard-learned system just because they said something you can ignore, especially because many if not most pairs play a conventional double?

If you mean "systems on after we double their 1NT" (for penalty), run. Do not even look. First, the best penalty doubles are where you can lead your fourth-best J of 7, or the similar "one-loser suit with an ace". If this gets pulled, I know where to play and you don't. Second, you should not be planning on pulling 1NTx (enough to have lots of system against it). You pull in two situations: "I'm too weak to sit for this, and I have a long suit that will score many more tricks as trump than on defence" and "I don't think we are getting this enough to beat our likely game, when we can place all the outstanding high cards". The first means you want to be able to play 2♣, not 3♣, if that's the suit; the second is so rare you can assign 2NT to it and "guess" your way to game.

Plus, I guarantee that at least half the time, one of you will forget, or think you're playing it when partner is saner, and that invariably leads either to a poor score or a director-assigned (poor) score.

Oh, right! I think I misread the OP's question.

Larry Cohen does suggest the "systems on" approach for a penalty double of a weak notrump opening - https://www.larryco....-vs-notrump-556

[P_Marlowe]

#1 playing a penalty double against a strong NT is, ok, the robots play it, but it may
not be very common. If you play in groups, that regular psych a strong NT, the penalty X
has some attraction.

#2 If we make a penalty double against their strong NT, playing the same system, one plays,
when having opened 1NT is not bad, it seemed reasonable when I heard about this treatment.
Most of the time you will pass the X, either with conviction, or due to a lack of an alternative.
Having a way to scramble to 2M via a stayman inquiry is not bad, it will be useful some of time.
Is it common? I guess not. But than again, it is a rare seq., the freq. is pretty low, as long
as you are certain, that you and your p know, what they are play, you will be ok.

Keep in mind, I dont play a penalty X against a strong NT, not even against a weak NT.

[pescetom]

 mycroft, on 2025-February-14, 08:06, said:

If you mean "systems on after we double their 1NT" (for penalty), run. Do not even look. First, the best penalty doubles are where you can lead your fourth-best J of 7, or the similar "one-loser suit with an ace". If this gets pulled, I know where to play and you don't. Second, you should not be planning on pulling 1NTx (enough to have lots of system against it). You pull in two situations: "I'm too weak to sit for this, and I have a long suit that will score many more tricks as trump than on defence" and "I don't think we are getting this enough to beat our likely game, when we can place all the outstanding high cards". The first means you want to be able to play 2♣, not 3♣, if that's the suit; the second is so rare you can assign 2NT to it and "guess" your way to game.

Plus, I guarantee that at least half the time, one of you will forget, or think you're playing it when partner is saner, and that invariably leads either to a poor score or a director-assigned (poor) score.

I would run from playing double of strong NT as penalty, it was a long term loser in my experience (unlike our current agreement to promise a 4M5m).
But if one plays it, I agree that playing systems on is not a great idea, even if your systems allow you to play in 2♦ as ours do. Being able to scramble to 2M is probably worth as much as being able to play 2♣, but natural bidding has the advantage of putting the opener on lead (not huge here, but still).

[mycroft]

jdiana, on 2025-February-14, 08:31, said:

Larry Cohen does suggest the "systems on" approach for a penalty double of a weak notrump opening - https://www.larryco....-vs-notrump-556

I find that fascinating, because as I said, I want to pull the double in exactly two cases, in one of which I *really* don't want to be forced to choose between -380 and the 3 level.

Having said that, he also suggests a very aggressive penalty double (13+; I'd prefer 15 if balanced, maybe 14 if against (10)11-13). My experience is that fourth hand frequently has a "5-7ish" hand where "if partner is a minimum, 1NT is making; should I pull it?" or a "7-9ish with a suit" hand where "1NT is going down, but if partner has extras, -300 loses to game". In both of those cases, it is *impossible* to get it right. "The opponents will tell us when we have extras"; yeah, not especially if the opponents' defence allows them to happily pass looking for -1, which might make if we slip up in defence just once. I'm guessing that if you're pulling the double more often than not, it's more right to play as if you had opened a "13-15" NT than the style I prefer. But I don't want to do that.

I don't deny either LC's teaching or bridge skills are much better than mine; and maybe if you defend as well as he and Bergen or Berkowitz did, passing the random 5s and 6s opposite usually 13s or 14s isn't as much of a loser as it would be for me. And maybe it is right in general - I see several here whose opinions I value highly and who play against the weak NT more than I who agree with his style. But he's teaching people who are confused by the weak NT existing, not those people.

To me, the primary purpose of a double of a weak NT is to bring partner up to the same knowledge level as the opponents about who has the balance of power, whether the opponents run or not. "13+, 17+ with an overcall-worthy suit" - doesn't.

[helene_t]

Nope, when partner doubles for penalty we need a way to bid with 5 or six small clubs and zero points. For constructive hands we don't need a system we just pass. Usually, it is more lucrative to defend 1nt x than to play game ourselves.

If you have a strong and very unbalanced hand where you fear that defending 1ntx will score less than your own game, you can improvise 2nt which obviously can't be a natural bid. You can also agree that a jump to 3 is forcing.

If you have a very weak hand suitable for garbage stayman, you can improvise 2cl, thinking that maybe playing 2cl undoubled is cheaper than defending 1ntx. And if they double 2cl you have the perfect hand for redouble. I am not sure if this is a good idea though since you can always just pass and hope p can take 1nt down by himself.

[mycroft]

Those of you that have read this story (many times) before, feel free to scan on...

A very good player in Calgary passed his partner's double of 1NT with a 2 count. Dummy even redoubled for blood with 11. At IMPs.

OL led his fourth-best spade - J - of seven.