[nullve]

Do you still play lebensohl, for example? If so, how does that work when opps' suit is clubs?

[ulven]

2D negative, 0-6/7.

[straube]

Herbert Negative..

http://www.bridgeguy...y_advancer.html

[pescetom]

I just love the fact that "Partner doubles a natural 2C opening. How do you respond?" is confined to Non-Natural System Discussion

[helene_t]

Everything natural, except 3♣ of course, which just follows whatever agreements you generally have for responses to t/o doubles.

It's not much different from a double of a natural 1♠ opening, except that 1NT is not available.

[dokoko]

IIRC the following structure was recommended by Eric Kokish:

(2♣)dbl
2♦ = negative*
2M = nat, constructive (8-10 pts)
2NT = puppet to 3♣^
3♣/3♦/3♥ = inv+ transfers
3♠ = transfer to 3NT lacking a ♣ stop
3NT = to play
4M = to play

*Doubler usually bids 2♥ over the negative 2♦. Then responder signs off in 2M or 3♦, invites naturally with 2NT or shows a constructive hand with diamonds (8-10) with a 3♣ rebid.

^Doubler usually bids 3♣ over 2NT. Then responder shows both majors (inv+), bids 3M naturally (FG with ♣ stop) or 3NT (♦ length with a ♣ stop).

3-level transfers usually deny a ♣ stop when responder is strong enough to force to game.

4m responses (directly or via 2NT) and 4M via 2NT are used to show two-suiters (4M+6♦/5M+5♦), but the structure is playable without that.

[nullve]

helene_t, on 2018-August-16, 15:55, said:

Everything natural, except 3♣ of course, which just follows whatever agreements you generally have for responses to t/o doubles.

Seems good enough if 2♣ promises opening strength, since slam is unlikely.

dokoko, on 2018-August-18, 00:56, said:

IIRC the following structure was recommended by Eric Kokish:

(2♣)dbl
2♦ = negative*
2M = nat, constructive (8-10 pts)
2NT = puppet to 3♣^
3♣/3♦/3♥ = inv+ transfers
3♠ = transfer to 3NT lacking a ♣ stop
3NT = to play
4M = to play

*Doubler usually bids 2♥ over the negative 2♦. Then responder signs off in 2M or 3♦, invites naturally with 2NT or shows a constructive hand with diamonds (8-10) with a 3♣ rebid.

^Doubler usually bids 3♣ over 2NT. Then responder shows both majors (inv+), bids 3M naturally (FG with ♣ stop) or 3NT (♦ length with a ♣ stop).

3-level transfers usually deny a ♣ stop when responder is strong enough to force to game.

4m responses (directly or via 2NT) and 4M via 2NT are used to show two-suiters (4M+6♦/5M+5♦), but the structure is playable without that.

I like this!

It can be found on page 351 in the Kokish-Kraft system notes.

[dokoko]

nullve, on 2018-August-18, 08:04, said:

I like this!

It can be found on page 351 in the Kokish-Kraft system notes.

A somewhat similar structure can be played vs. a natural 2♦ opening - obviously without an artificial negative:

- 2NT includes a weak hand with clubs, otherwise same follow-up.
- 3♣ is nat inv (nonforcing)
- 3♠ shows/includes strong club hands (your choice)
- other bids unchanged

As there is no artificial negative, advancer should invite or force to game a bit more aggressively IMO. If you prefer, you might use 3M via 2NT to show constructive hands and keep invitations up to strength.

I modified Kokish's structure as follows: A direct 4m response to the double shows 4♥&6om (nat=inv, opp's m=FG), while 4m via 2NT shows 4♠&6om.