Two-way Checkback

Two-way checkback, introduced by Kit Woolsey in an article in Bridge Today, uses the rebids of two of either minor by responder after opener's 1NT rebid as artificial and forcing. In the Woolsey style, 2C: puppets to 2D: to play 2D: or 3C: or to invite game in various strains. 2D: over 1NT is artificial and game forcing.

Two-way is super if playing weak notrumps, so that a 1NT rebid by opener shows extra values. With those methods, responder will often have a game forcing hand; indicating that at the level of 2D: is quite helpful. Two-way also is nice when playing Walsh-style responses to 1C:, because responder can play 2D: without fear of correction back to his short major.

Details are below with a few interesting tinkers.

"Purish" means "most of the high cards in the long suits. "m" means a minor suit; "M" means a major suit; "OM" means the other major; "om" means the other minor.

1m-1M; 1NT-?
2C: = relays to 2D:
2D: = game forcing, asks for shape
2M = to play
2OM = if hearts, no game interest
if spades, 4-4, invitational, not forcing
2NT = natural invitational 1
3m = game forcing, purish 5-5
3om = game forcing, purish 5-5
3M = game forcing, purish 6+
3OM = if hearts, game forcing, purish 5-5
if spades, game forcing, purish 6-5
3NT = to play

Higher bids:
4C: = Gerber (RKC?)
4D: = usually 6331 with stiff, very good suit, slam interest
4M = to play
4oM = stiff, same as 4D:, I guess
4NT = natural, invitational (what's 2D:...4NT?)
2C: sequences:
1m-1M; 1NT-2C:; 2D:-?
2M = 5 card suit, invitational, nonforcing
2OM = if hearts, 5-4 or 5-5, invitational, nonforcing
if spades, 4-5 invitational, nonforcing
2NT = invitational, shows opener's minor 1
3C: = to play 1
3D: = invitational, natural
3M = strong invite, 6+
3OM = if hearts, strong invite, 5-5
if spades, ?
3NT = 5 card M, choice between 3NT and 4M
higher bids = ?
2D: sequences:
1m-1M; 1NT-2D:; ?
1) bid 4 of the other major
2) bid 3 of responder's major
3) rebid a six-bagger
[4] show 2-2-4-5 or 2-2-5-4?
5) rebid 2NT
This set of choices is due to Woolsey, probably mostly intended for weak NT systems; this is most likely to get the partnership to play the hand from the strong NT's side. He claims that it doesn't really matter which of the first two is highest priority, and some others prefer to show 3-card support first, while others prefer to bid hearts first.
1m-1M; 1NT-2D:; any-?
2S: = if 1M = 1S:, then 2S: = 6-card suit, notrumpy hand
if 1M = 1H:, then 2S: = ?
2NT = 1 random and forcing with doubt about 3NT? (probably 17-count)
3any = game forcing, notrumpy 5-5 or 6+ single suit
3NT = to play

We play 2-way Checkback after 1H:-1S:; 1NT and 1C:-1D:; 1NT, also. All sequences are what one might expect, but here are some examples:

1H:-1S:; 1NT-2D:-?
2H: = good 5-card heart suit
2S: = two good spades, say Q10 or better
2N = nothing special
3m = solid stopper, weak doubleton in other minor
1C:-1D:; 1NT-?
2C: is how we get to 2D: and 3C: contracts
2D: is still artificial and game forcing
2C: then 2NT is invitational with clubs
1 Ed Davis came up with some tinkers to this to add accuracy at the cost of memory. Here they are.
1m-1M; 1NT-2NT is a relay to 3C:
1m-1M; 1NT-2NT; 3C:-?
pass = signoff with clubs
3D: = m support (4+,) lower stiff
3oM = m support (4+,) higher stiff
3M = 5224 (4m, 5M,) doubletons are xx.
3NT = 4225 (5m, 4M,) doubletons are xx.
1m-1M; 1NT-2C:; 2D:-2NT = natural, invitational
1m-1M; 1NT-2C:; 2D:-3C: = natural, invitational
1) show hearts
2) show spades
3) bid 5+ card minor, good suit
4) bid 2NT

Jeff Goldsmith, jeff@tintin.jpl.nasa.gov, April 15, 1996