[mycroft]

Okay, since we seem to be in "please help" mode here, here's a situation we're having trouble with recently - they interfere after 1C-p-1D. Standard Modern Precision, 16+unbal, 17+bal, 1D any NGF. Without the interference, we play 1H "hearts or (certain) big balanced), 1S/2m passable, 2M/3m F1 and standard 2C strength. We're not 800-page system crazy, but do play different defences to 1C-X, 1C-1D, 1C-1M, 1C-1NT, and 1C-2C+; so we can handle a certain amount of complexity.

Any ideas?

[Free]

Pass = semipositive
Dbl = double negative
1♥+ = GF original system

If you get the chance after 1♣-1♦-Pass-Pass, you Dbl as relay, and responder can start bidding his hand.

You can also swap Pass and 1♥+ if that fits your system. This way you'll be better of to compete.

[straube]

If interference at 1H or less, systems on (e.g. dbl of 1H is strong)...

If interference at 1S or more, maybe just...
dbl- takeout or bigger hand
cue bid-GF, two-suited
other-natural
jump shift-invitational, nf

the more space 4th hand takes up, the more the strong hand is required to have for direct action

[Mbodell]

Your auction is forcing through 1♠ with no interference, so I think you can keep it as forcing through 1♠ (possibly even higher like through 1nt), so a pass of a 1♥ overcall can be forcing. If the overcall is 1NT and two suited then you can apply your normal 2 suited defense (X for some penalty oriented agreement, U/U, etc.). If the overcall is at the two level, my partner and I have been playing with using some form of lebensohl which seems to work pretty well, but usually is better for responder to bid (so over 1♣) than for opener to bid (over 1♣-1♦). We actually use a transfer oriented system where 2x is weak and natural, and 3x shows an inv+ in x+1 (opener bids 3x+1 if they would not accept the invite, and responder bids on to show gf).

A reasonable question to figure out is what is X and what is P by opener after 1♦. And are you willing to P with a minimum and with a penalty pass and if responder reopen with a X on balanced non-super bad hands, knowing that occasionally you'll miss your big number? If so then a simple X is negative or super strong, new suit is natural, and pass is minimum/bal or penalty oriented probably works ok.

[Echognome]

It's been awhile, but I believe we played pass by opener as super positive (then double by responder as double negative). The other bids by opener showed a limited opener, including double which was takeout.

I don't really have any strong feelings on the auction. It's just one of those things you have to discuss with your partner.

[jdonn]

I think the best is just to very simply play pass is nothing in particular, everything is natural, double is takeout, jumps or a cuebid is significant extras. I certainly want to be able to pass on balanced hands that either don't have the right stopper or are very minimal, or where they have bid my main suit.

The only thing I would add further is I would be very aggressive bidding a 5 card major in interference there on essentially any hand if I can do so on the 1 or 2 level. It's just so important to get the suit in before the overcall is raised to some high level.

[awm]

I pretty much agree with what others have said.

I'll mention that my style is usually to make a cheap natural rebid if one is available (i.e. over 1♣-P-1♦-1♠ I'll bid 1NT on a balanced hand with a spade stopper). But I've had at least one partner who prefers that balanced minimums always pass and that bidding notrump definitely shows about a king above minimum. When we play together I go along with him on this... I am less comfortable however with the idea that bidding 2♥ in the same auction shows more than minimum...

[mycroft]

Thanks everyone! Now for discussion and practise...