The Checkback Family

The Checkback Family is New Minor Forcing (NMF), Fourth Suit Forcing, and XYZ. NMF has a variant, Two-Way New Minor Forcing (TWNMF). The first two conventions were covered in Bidding Notes; TWNMF and XYZ are described in detail in this chapter.

The motivation of each of these bids is to ascertain whether there is a fit to responder’s suit when responder has promised only four cards but might be longer. Because of the bidding room they consume, they require invitational to game-forcing hands.

New Minor Forcing and Fourth Suit Forcing are virtually always played together, and virtually always included when playing 2/1 or Precision. The variant Two-way New Minor Forcing (TWNMF) distinguishes invitational vs. game-forcing hands by using both 2♣ and 2♦ as artificial.

XYZ extends the idea of TWNMF to the case of the opener’s rebid being one of a suit, and is so-named because the auction has begun 1x - 1y - 1z. Since it is identical to TWNMF if “z” is no-trump, the two conventions are played together. In this approach, it is still possible to have a fourth-suit auction such as 1♥ - 1♠ - 2♣ - 2♦!.

As we will see, TWNMF and XYZ are especially suited to Precision.

Two-Way New Minor Forcing

Two-way New Minor Forcing (TWNMF) applies after a 1N rebid by opener after responder bids a major. Responder distinguishes invitational vs. game-forcing hands with his first rebid.

Note that in the case of playing a weak notrump, opener after 1m - 1M - 1N!(15-17 bal), opener has not denied the other major, whether M was hearts or spades, and has not denied 3-card support for M.

None of this applies to Precision auctions that began 1♣!.

Invitational Hands

We bid 2♣!(artificial) with invitational hands containing five of our major or four of the other major. Opener must rebid 2♦!(forced). The bid should be explained as “invitational with five of our major or four of the other major, or a weak hand with diamonds”.

Then, in the case of 1m - 1♠ - 1N - 2♣!(artificial) - 2♦!(forced), responder bids:

  • Pass - signoff in 2♦.
  • 2♥- Invitational with 5 spades and 4 hearts.
  • 2♠- Mildly invitational with 5+ spades.
  • 2NT - Invitational, with 4-card support for opener’s minor. This allows opener to sign off in 3 of the minor if he wishes.
  • 3♣- Invitational with 4 spades and clubs.
  • 3♦- Invitational with 4 spades and diamonds.
  • 3♥- Invitational with 5-5 in the majors.
  • 3♠- Invitational with 6 spades.

If responder’s suit had been hearts, make the corresponding changes:

  • Pass - signoff in 2♦.
  • 2♥- Mildly invitational with 5+ hearts
  • 2♠- Invitational with 5 hearts and four spades
  • 2NT- Invitational with four-card support for opener’s minor.
  • 3♣- Invitational with 4 hearts and clubs
  • 3♦- Invitational with 4 hearts and diamonds
  • 3♥- Invitational with 6 hearts

If responder does not have support for opener’s minor, and no interest in pursuing a major fit, he raises 1N to 2N and does not use TWNMF. In the sequences above, the 3m bids show either support for the 1m opener or a decent suit and invitational values.

Game-Forcing Hands

The responses for 2♦! are as in NMF, but we can be assured we are not stopping short of game and use a slow-shows approach to slam. Opener should not jump.

Priorities for opener remain as in NMF:

  • With four of the other major, bid 2W
  • With 3-card support for M, opener should bid 2M. However, with a flat hand and the points mostly not in M, consider 2N.

Weak Hands

If you have a weak hand and bypassed a five-card diamond suit to bid a four-card major, you can bid the 2♣!(relay) and pass the obligatory 2♦!(forced).

With 5 or more in M, bid 2M to drop dead. With five spades and four hearts, bid 2H showing your shape; opener can pass or correct. It should do better than 1N.

Finally, we have the problem of a weak hand with clubs. A bid of 3♣ over 1N is weak and to play. (With a better hand we’d go through the 2♣ or 2♦ bids first and then bid 3♣).

Responder Jump-Rebids

After the 1N rebid, a direct bid of 3M shows a slammish hand with a good suit. We could go through 2♦! first if we were just game-forcing. A jump to 3♦, such as 1♦ - 1♥ - 1N - 3♦ is slammish in diamonds. But a jump to 3♣ is weak, as noted above.

TWNMF is off by a passed hand. However, playing a weak 1N, the 1N rebid shows a strong notrump hand. In that case the passed hand may still be invitational or game forcing so TWNMF is on.

TWNMF is off after interference.


XYZ is a convention that applies when the first three bids are on the one level, and responder has an invitational or better hand. The name comes from writing this as 1X - 1Y - 1Z. The Z can be notrump. It does not apply to Precision auctions over 1♣!.

Essentially we extend the ideas of TWNMF to auctions where the opener’s rebid is 1♠ not 1N.

Advantages to XYZ: you get to play refused invitations at the two level, and you get to start investigating slam at lower levels. Disadvantage: responder gives up the ability to play 2♣ after auctions that began with 1♣. (So for Precision players, no disadvantage at all.)

Since you’ll be playing what amounts to TWNMF at the one level, it is consistent to play TWNMF at the two level as well.

XYZ applies for these sequences:

  • 1♣ - 1♦ - 1♥/1♠/1N (does not apply in Precision)

    After 1♣ - 1♦ - 1♥, either 1♠ or 1N is natural; 2♦! is the game force.

  • 1♣ - 1♥ - 1♠/1N (does not apply in Precision)

  • 1♦ - 1♥ - 1♠

  • 1♦ - 1♠ - 1N (same as TWNMF)


It is suggested that XYZ is off in competition or by a passed hand.

After 1x - 1y - 1z, we are essentially playing TWNMF.

  • 2♣!(artificial, relay to 2♦!) in most cases shows an invitational hand. Opener should show a 3-card fit. Responder can pass 2♦ to play in diamonds.
  • 2♦!(artificial, gf) is game forcing and bidding proceeds as in TWNMF;
  • 2♥ or 2♠ rebids are drop-dead to play.
  • 2N is invitational.

Followups after the 2 Club Relay

After the 2♣!(forcing, usually invitational) - 2♦!(forced) relay, the followups are:

  • pass is to play in diamonds.

  • 2♥ / 2♠ are invitational promising five of the major.

  • 3♣ is to play in clubs.

  • 3♦ is invitational

  • 2N is invitational with support for opener’s minor.

  • If opener has freak distribution, he can break the 2♣! relay, such as:

    1♦ - 1♥
    1♠ - 2♣(relay to 2♦)

    indicating diamonds and spades, diamonds longer than the spades.

  • Similar to Lebensohl, there are two ways to make some invitational bids, such as 2N directly or 2♣! then 2N. Partnerships could assign different shades of meaning to these bids.

Note that fourth suit forcing to game is covered by the 2♦! bid, which might not be the actual fourth suit, as in 1♦ - 1♥ - 1♠ - 2♦!(GF) where we do not bid 2♣ as the fourth suit.