2-Suited Weak Twos

Original notes by Rob Forster
Edits / Additions by Ben Leitner

Introduction:

Playing some systems, you have 2 and maybe even 2 available for preemptive bids.  As an alternative to normal weak two bids in all suits, consider instead using these bids for 2 suited preempts.  Depending on your minimum standards for shape, this style of preempts is more frequent and while still being reasonably safe. 

2: + Major
2: + Major
2: +
2: Normal weak 2

Each suit will range from 4-6 in length, and either suit can be longer.  You should not be 3 suited (not 4441 or 5440 shape).  Remember that traditional 6 card single suiters are sometimes suitable to be opened at the 3 level.  Notice that hands with awkward shapes and near opening values (like 4/5) can now be easily described by a weak two bid.  On the other hand, shapes with easy rebids like 4-3-5 are better opened at the one level, as the weak 2 bid can sometimes bury a possible 5-3 heart fit.

ACBL Legality:

While you can play these promising only 4/4+ in the two suits in question (since the bids promise 4+ in the suit opened and hence are “natural”), conventional continuations are not allowed under GCC if your weak two bid might have only 4 cards.  The methods below are conventional, and so should be used when the weak bids promise 5+ in the suit bid and 4+ in the other suit.  Feel free to play them as 4/4+ in club games, online, etc; however, the shape relays below will need to be modified to show the additional 4/4, 4/5, and 4/6 shapes.

Frequency:

One can expect to hold a two-suited 2/2 opener with 4-9 HCP about 6.07% of the time.  Compare this to a weak 6-card minor holding, with no 4-card major or 2nd 5-card minor.  With 4-9 points, this happens about 2.33% of the time.  The weak two-suiters are about 2.6 times more likely.  This assumes 5+/4+, for the shape requirement.  If we also make this bid with as little as 4/4, the probability jumps to 17.81%, fully 7.6 times as often as a normal weak 2.  Since conventional responses to these bids cannot be used in GCC events, and would require adjustments to the relays anyway, we will focus on the 5+/4+ shapes.

"Lawfulness"

Another thing to consider is how dangerous these bids can be.  As with all preemptive bids, there is a chance that partner may not have much for you, and the opponents double you off.  The Law of Total Tricks is a premise that you can safely bid to a level equal to the length of your fit and still be safe.  That is, if the opponents still set you several tricks, they probably had a game or even a slam available.  It is thus a good idea to know how often there will be a 8+-card fit when these bids are opened.  Using my Hand Calculator program, I computed that the best fit in one of opener's suits when opening a two-suited weak 2/ would be:

Fit Size Probability
5-6 2.21%
7 17.68%
8 38.45%
9 29.35%
10+ 12.31%

thus, these 2-suited bids have at least 80.11% chance of being safe from a Law of Total Tricks standpoint, and if the fit in both of opener's suits is very small, then responder is likely to have a long suit of his own to run to.  Compare this to the probabilities for fit sizes on the long suit of a 6-card minor preempt:

Fit Size Probability
6 4.28%
7 19.46%
8 33.36%
9 27.80%
10+ 15.11%

Here the probability of an 8+-card fit is only 76.26%, still very high, but not quite as high as the two-suited preempt, which also occurs more often.

Basic Response Methods:

For 2, responder’s weak options are to preemptively raise clubs or to bid 2-3M as pass/correct for opener’s major (or back to clubs).  2 asks for the other major, either to play or as an invitational hand.  2NT is a GF asking bid.

For 2, weak responses include raises of diamonds or 2-3M as pass or correct.  2M followed by 3M is to sign off in your own major (long clubs cannot be shown).  2NT is an invitational hand, either looking for a fit or with it’s own long major.  3 is a GF inquiry

The 2 opening is the simplest since both suits known.  2NT is a general inquiry, invitational or better.  All bids in a major are to play.

Responses over 2: 5+/4+M, 4-9 points.

2 Tells opener to bid the major he does not have at the 2 level.  After opener's rebid:
Pass To play in your own 6+-card suit.
2 Invitational with a fit.  Min hands pass, others show shape.
2NT General invitational asking bid.  3 is a minimum response.  Higher responses are GF and show shape.
3 Any minimum.  All further bids are NF.
3 4M / 5.  3 of the other major asks for 3-card support (3NT denies)
3 5M / 5
3 4M / 6
3NT 5M / 6
4 6M / 5
4 6M / 6
3 To play.
3 To play, long diamonds and no major tolerance.
3 To play, surprise fit.
2 Pass or correct for opener's major.  Further new suit bids are NF
2 Pass or correct for /.  Further new suit bids are NF.  Opener shows -length in steps.
Pass and
2NT 4 and
3 5 and
3 6 and
2NT GF inquiry, responder shows which major and suit lengths.
3 and 5.  After 3 asking:
3 4
3 5
3NT 6
3 4-5 and 5.  After 3 asking:
3 4
3NT 5
3 4 / 6
3 4 / 6
3NT 6 / 5
4 5 / 6
4 5 / 6
4 6 / 6
4 6 / 6
3 Blocking / Preemptive
3 GF with long
3/ Pass-or-correct
3NT To play
4/ Preemptive
4/ To play.

Responses over 2: 5+/4+M, 4-9 points.

2 Pass-or-correct.  A 3 rebid is a signoff.
2 Pass-or-correct. Bids of 2NT through 3 show length (4,5,6) as over 2, above. A 3 rebid is a signoff.
2NT Invitational inquiry.  After response, 3OM is an invitational single-suiter.
3 Min with
3 Min with
3/ Max with 4-5 of the suit bid
3NT Max with a 6-card major.
4 Transfer to your major.
4 Bid your major.
3 GF inquiry.
3 + (Transfer).  3 asks for 3-card support (3NT denies).  After 3 asking length:
3 4 / 5+
3NT 5 / 5+
4 6 / 5
4 6 / 6
3 4 / 5+ (Transfer)
3 5 / 5+
3NT 6 / 5
4 6 / 6
3 Preemptive.
3/ Pass-or-correct
3NT To play
4 GF with long
4 Preemptive.
4/ To play

Responses to 2: 5+ / 4+, 4-9 points

2 To play
2NT Asking bid showing at least invitational values.  3 shows a minimum.  3 and above show shape (GF).
3 Any minimum.  3 inquires further:
3 4 / 5-6 (NF)
3 5 / 5 (NF)
3NT 6 / 5 or 5 / 6:  4 asks to transfer to the longer suit.
4 6 / 6
3 Max (GF): 4-5 / 5.  3 asks for length.
3 4 / 5
3NT 5 / 5
3 4 / 6 (Transfer)
3 5 / 6
3NT 6 / 5
4 6 / 6
3/ GF with long minor.
3/ Preemptive
3NT To play
4/ Preemptive
4/ To play