Two-Way Checkback

The Problem

After opener rebids 1NT (for example after 1C:-1D:; 1NT), we want to be able to signoff, invite, and force in all the suits. That's not possible in standard methods. New Minor Forcing can help, but since opener must jump with a non-minimum (or we can never stop at the two-level), it uses a lot of space. It'd be nice if we could set a game force at the two-level.

The Solution

Kit Woolsey solved the problem. The basic idea is to have responder's 2C: rebid force 2D:. Then his further bids are invitational. Since he can just pass opener's 2D:, responder's 2D: rebid can now be artificial and game forcing. Simple bids are signoffs, and jumps are all forcing. This gives us not only lots more room for game forces, but we often have multiple ways to bid similar hands. One problem is that we can't stop in 2C:, but if that's right, we won't get to play there anyway. How to stop in 3C: is up to partnership agreement. We'll cover that later.

When is it on?

If the opponents haven't bid (optionally on if they double). If we have opened one of a suit, responded one of a suit, and rebid 1NT. Only these auctions. It is on after 1C:-1D:; 1NT and 1H:-1S:; 1NT. It does not apply to 2NT rebids.

The Basic Structure

1x-1y; 1NT-?
2C: = relays to 2D:
2D: = artificial game force
2y = to play
2NT = natural, invitational1
3anyBelowY = pure 5-5 hand game forcing
3y = pure 6+-card suit, slam try
4new = splinter
Let's do one example to flesh out some of the details.
1C:-1H:; 1NT-?
2C: = forces 2D:
2D: = artificial game force
2H: = to play
2S: = specifically 4-4 in the majors, invitational
2NT = natural, invitational1
3C: = 5-5, purish, game forcing
3D: = 5-5, purish, game forcing
3H: = 6+ hearts, good suit, slam interest
3S: = 6+ hearts, self-splinter
3NT = to play
4C: = 6+ hearts, self-splinter
4D: = 6+ hearts, self-splinter
4H: = to play

Recap of Responder's Rebids

If responder is weak (less than invitational values), he only has a few choices. He can pass, of course. He can rebid his suit (unless it's diamonds), to play. He can bid 2C: to stop in 2D:; he'll then pass opener's forced rebid. There will be a way to sign off in 3C:. (See below. Later.) Or with at least 5-4 in the majors, he can rebid 2H: (1m-1S:; 1NT-2H:), which is weak and promises 4+ hearts.

If responder is invitational, he must bid 2C:. Opener will rebid 2D:, and anything he bids is invitational. There are two other possible invitational sequences; if he responded 1H:, a 2S: rebid shows exactly 4-4 in the majors and invitational values. You might be playing 2NT as natural and invitational. (See below. Later.)

If responder has a game force, he has lots of choices. If he knows the contract he wants to play, he just bids it. 3NT, four of his major, 6NT, etc. are natural and to play. If he has a very pure hand, either a great suit and slam interest, or two good suits, he can jump the bidding. That's forcing and very descriptive. If he doesn't know what to do and no jump leaps out as descriptive, he bids 2D:. Opener bids naturally, and you figure out the final contract after possibly several bids.

There is an exception or two to these rules, but that's more or less responder's prescription.

2C: Sequences

2C: is used for one of three types of hands. (1) a hand that wants to play in 2D:. Any invitational hand (except maybe a natural 2NT), and some rare game forces. An example:
1C:-1H:; 1NT-2C:; 2D:-?
Pass = that's how we play 2D:
2H: = natural, invitational, 5 hearts
2S: = five hearts, four spades, invitational (but if opener does not often bypass a 4-card spade suit, just bid 2H: instead of 2S:)
2NT = natural, invitational1
3C: = natural, invitational
3D: = natural, invitational
3H: = 6+ decent hearts, invitational
3NT = 5 hearts, some 5-3-3-2, interest in 3NT, choice of games
3S: or more = up to partnership agreement. I like to play these jumps as void self-splinters, though logically, the direct jumps should be voids (more pure) and slow ones singletons (less pure).

2D: Sequences

1x-1y; 1NT-2D:; ?
Priorities: (These are somewhat up to partnership agreement.)
1) show four of the other major
2) show three of responder's major
3) show a 5- or 6-card suit
4) show a new four-card suit
5) bid 2NT
These are due to Woolsey, but some flexibility is available here. If your hand screams NT, it's probably right to bid it. There are more complex ways to show opener's entire shape (see Rodwell's bidding book), but this is simple enough.

Later Auctions After 2D:

Note that immediate (not after 2D: jumps are "purish." That means your high cards are in your long suits, and you are at least 5-5. If you go through 2D: and then bid at the three-level, that shows either an impure 5-5 or sometimes only 5-4 (if the four is partner's suit).


Responder's 2NT Rebids

You may have noticed some footnote references above. The (1) note refers to the fact that 1x-1y; 1NT-2C:; 2D:-2NT and 1x-1y; 1NT-2NT seem to show the same hand. Standard practice is to play the first auction also promises four cards in opener's minor. Then three of his minor is to play.

Stopping in 3C:

I have been careful not to mention how to stop in 3C:. There is no standard for this; in fact, three common ways exist.

Slow Stop

1x-1y; 1NT-2C:; 2D:-3C: is to play. Note that we no longer have a way to invite in clubs. In that case, the slow route to 2NT is a club invite.

Fast Stop

1x-1y; 1NT-3C: is to play. We no longer have a pure vs. impure forcing club rebid. All club game forces go through 2D:.

2NT is a Relay

If you give up the two ways to rebid 2NT, you can play that 2NT relays to 3C:, either to play there or with some game forces. I like these rebids:
1x-1y; 1NT-2NT; 3C:-?
All bids show 9 cards in x+y.
3D: = lower side singleton2
3H: = higher side singleton2
3S: = 5x-4y-2-2
3NT = 4x-5y-2-2
2 You can play the next step asks for length in the major. I have not found that necessary.

For example:

1C:-1H:; 1NT-2NT; 3C:-?
3D: = 3-4-1-5 or 3-5-1-4
3H: = 1-4-3-5 or 1-5-3-4
3S: = 2-4-2-5
3NT = 2-5-2-4 with NT interest. (You could just bid 2D: and bid game in the major if you found a fit and were not interested in 3NT.)

Advanced Topics


Some play that if opener rebids one of a major, these methods are still on. This is called "XYZ" because the auction is described, 1x-1y; 1z. It stays on if z = NT. This is not clear to use if opener's one of a major promises an unbalanced hand, for example, in the Walsh approach, 1C:-1D:; 1H: promises five clubs, so being able to play 2C: has a lot of value.

Responder has 5-3-3-2 with a Major

One of the cool uses of this convention is it strongly helps you to decide between a 5-3 major suit fit and 3NT. When responder is balanced, and opener has strength opposite his doubleton, 3NT will often take as many tricks as the major. Sometimes that number of tricks is 9, making 3NT a big winner.

Responder has four ways to bid 5-3-3-2s. These are the ways with increasing interest in playing the major. Let's say the auction begins 1D:-1S:; 1NT.

  1. Least interest in a 5-3 major suit fit. Jump to 3NT. "Least" here means "zero." A good example is  S:xxxxx H: KQ10 D: Ax C: AQJ. You have zero interest in 4S:, as it could easily go down when 3NT is gin.
  2. Some interest in 3NT, some in four of the major. Relay to 2D: and bid 3NT. Opener should pick the major with a suit-oriented hand or any 3-card holding and a reason to avoid 3NT. An example hand is  S:KQxxx H:AJx D:xx C:Kxx.
  3. Plan to bid four of the major unless partner shows strength in your weakness. Bid 2D:. If partner doesn't show support (possibly on the next round if he bids 2H: and you bid 2S:), then no problem, bid 3NT. If he shows support, bid your strength. If he doesn't show strong interest in 3NT and stuff in the right place, you play four of the major. An example hand  S:KQ10xx H:xx D:Kxx C:AJx. Unless partner bids hearts and then notrump, you're playing the 5-3 fit if it exists. Two possible auctions
    1. 1D:-1S:; 1NT-2D:; 2S:-3C:; 3D:-4S:
    2. 1D:-1S:; 1NT-2D:; 2H:-2S:; 3S:-3NT
  4. Plan to play four of the major if you have a 5-3 fit and not otherwise. For example  S:KQxxx H:xx D:AJxx C:Ax. In fact, you might even look for a 5-2 fit on this hand if you can diagnose heart (or maybe club) weakness. For example, 1D:-1S:; 1NT-2D:; 3C:-3D:; 3S:-4S:.

Some Tricks not Available with New Minor Forcing

If partner opens 1C:, you can show an invitational hand with a four-card major and a good five-card or any six-card diamond suit. Let's say you have  S:AQxx H:x D:Axxxxx C:xx. Start with 1D:, then over the likely 1NT rebid, relay to 2D: and bid your major. That's invitational and natural. So the auction starts 1C:-1D:; 1NT-2C:; 2D:-2S: on this hand. Bingo.

Partnership Decisions

I have made some statements about standard methods. Some are a little bit of an overbid. If a partnership adopts these methods, they should answer these questions. My preferences are noted.
  1. Is it on if they double? (Yes)
  2. Is it on if they bid? (No. A cue sets a game force.)
  3. Is it on over 1H:-1S: and 1C:-1D:? (Yes)
  4. How do we stop in 3C:? (Via 2NT)
  5. What's the difference between 2C:-2D:-2NT and a direct 2NT? (See above)
  6. Are higher jumps meaningful? (Yes)
  7. Is it on over non-1NT rebids (XYZ)? If so, which? (Varies by system)
  8. What priorities do you use to show suits after 2D:?

Jeff Goldsmith, Sep 7, 2020