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Methods Over 1 Interference

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Basic Methods:

The basic methods are mostly straightforward.  The responses depend on what the opponents bid.

Basic Methods over Interference

Over higher interference (1NT and above) any action is game forcing and double is negative (shape negative, not points negative).

Advanced Methods:

These methods were developed solely by me (Ben) and are not (so far as I know) currently being used by anyone. If you think they're interesting or useful, great, but they are entirely untested and no warranty is offered for them.

More advanced methods for handling interference depend on the nature of the overcall.  First, if the interfering bid is or 1, we can silently thank the opponents for their help as they have provided extra options for responder to describe his hand.  Over either of these overcalls, responder bids as in the basic methods above.

Over Natural 1/1 Interference:

Natural overcalls of 1 or 1 use up more bidding room, but also provide insight into the overcaller's hand and this, in turn, provides insight into responder's hand.  A simulation of 1,000,000 generated deals where South has a 1 opener and West has a 1/ overcall reveal that only about 10% of the time will responder have length in the bid suit.  We can therefore play modified systems-on and recover almost all of the space that has been used.  A summary of the responses follows:

Responder's Bids over Natural 1/ Interference

We have the following notes on the above table

1. 1-1-: To play as much systems-on as possible this should be a relay to 1NT to play systems on, just as if responder had bid 1 without interference.  This gives up the ability to distinguish between 0-4 and 5-7 point hands, but this is a distinction we don't have without interference anyway.
2. We use a system analogous to the usual 1NT showing and a minor.  We can simply use the same systems replacing with , but to better rightside contracts we can modify the first follow-ups to the following (after 2 by opener).  The 2nd follow-ups are exactly as in the normal methods.
   • 2: Shows longer than .
   • 2: Shows at least as long as the minor.
   • 2: Shows longer than .

   This bumps the -longer response up by one, but are higher anyway, so this is ok.

3. Single-suited : Follow-ups to this bid work exactly as in the normal systems, the only difference is that we show this shape with 2 rather than 2.
4. Single-suited : Again, the follow-ups are the same as normal single-suited hands, we just get here differently than usual for .
5. If we elect to use over 1 to show a balanced hand, this shows any 4441 hand just as in normal methods.  If, instead, shows 5-7, then this bid is a relay to 2NT showing a balanced hand.  This considerably lessens the amount of space we have, so I'd go the other way. If this bid shows a balanced hand, here are thoughts on further follow-ups after opener's 2NT.
   • 3: Shows 5332, where the 5 is not in overcaller's major.  After a 3 relay, responder shows his suit.  3 of overcaller's major shows the other major and the other two bids at or below 3NT show / (lower shows , higher shows ).  Opener can break the relay and bid 3M naturally instead of 3 to ask for 3-card support.
   • 3/3:  Whichever of these is appropriate is a transfer to a 4-card other (not overcaller's) major.  The other shows 5/4 or better in the minors.
   • 3: Shows 4/4 minors.
   • 3NT: A 33(34) hand, or maybe 4333 with 4 in the other major and a hand that didn't want to "transfer."
6. If over 1 shows a balanced hand, this bid can show length/stoppers in overcaller's major.  If shows 5-7, then this bid shows the 4441 hands.  After the 3 relay, responder bids his stiff at the 3-level and 3NT shows a singleton .

(Slightly More) General Interference:

The following methods are used when the opponents interfere at or below 2, and not with a natural 1/.  Before describing the initial bids, I introduce a set of systems that will be used.

Systems After 5-Card Major Denials:

One feature of many of these interference methods is that responder can deny a 5-card major with his first bid. In this case, responder can look for a major fit without having to distinguish 4 and 5 card suits. In addition to finding the major fit, we also wish to end up at the right level. It is possible that responder’s first bid did not clarify strength (either 0–4 or 8+ GF), or if responder has shown a 5–7 hand and opener is 16–19, it will be helpful to distinguish the 16–17 and 18–19 point hands. The exact methods depend on what bids are still available after opener’s rebid.

If 2 is Available:

This will happen when opener rebids 1NT or over a 1NT overcall.  This also applies if opener doubles 1 or bids 1 as an artificial force. In this case, the following systems are on:

If 2 is not Available:

This will happen if opener bids or doubles 2.  Here 2 is available but 2 is not.  In this case, bids are as follows:

The Methods:

The general ideas for responder's bids are as follows:

Pass	This shows 5–7 and denies a 5-card major. If 1NT is available to opener, it shows 16-19 points and is natural, if not the 16-19 balanced hands double.  2NT is natural and shows 20-22 points.  A cheapest new suit by opener is artificial and strong (20+ GF) and denies the ability to bid 2NT.  Other new suits are natural, showing 16-19 points. If opener's rebid is , 1NT, or the artificial force, and is below 2, the above systems after 5-card major denials are used.  Systems are also on over 2NT, although the bids are moved up to the 3-level.  If opener makes a natural suit bid, responder bids naturally, with raises showing a good 6 or 7 points.
	This shows either 0-4 points, or an 8+ (GF) hand without a 5-card major or 6-card minor. If 1NT is available to opener,  it shows 16–19 points and is natural. After 1NT, the above systems are on, but if responder bids on, it shows a GF hand. Opener can still distinguish between 16–17 and 18–19 point hands, as a strong responder may be interested in slam. The cheapest suit bid is artificial and very strong, willing to explore game opposite the 0–4 hand. Responder bids naturally. All other bids are natural and deny interest in game opposite a 0–4 hand. Further action by responder over these bids shows a GF hand, and over 2NT, the above NT systems are on.
2/	This bids are transfers to 5-card major suits and show 5+ points.  Accepting the transfer shows 16-19 points and 3-card support.  With a stronger hand and support, opener super-accepts to 3M (does not promise 4-card support).  After any acceptance, a new suit by responder is natural or a cuebid and shows a GF hand.  A raise of 2M to 3M is invitational.  Alternately, new suits can be game tries / slam tries.  Either way, they are forcing. Without support, opener bids the cheapest non-accepting suit (2 or 3) to force to game at which point further bidding is natural.  Other new suits by opener are natural showing 16-19 points.  Further bidding by responder is natural and GF.
2	A relay to 2NT showing a GF hand and one or both minors.  After the relay, responder bids his cheaper minor.  3 by opener over 3 inquires about diamonds.  3NT denies and 3M shows and shortness in the suit bid.
2NT	If overcaller's bid shows known suit(s), 2NT shows a balanced or semi-balanced GF hand with stoppers in those suits.  I expect this to be quite rare.
3	A GF hand with both majors.  Opener picks a major or bids 3 with no preference.  After this 3 bid, responder bids 3 of his weaker major (still trying to rightside, when possible).
3/	These bids show a GF hand and are transfers to a 6+-card suit.  Since these bids force to game, a simple acceptance is the stronger action and then responder can begin cuebidding in the search for slam.  A jump accept to 4M is a signoff.
3	Like 2, but very strong and/or distributional.  Looking for a minor slam.
Others	I have no idea.

Yet Higher Interference:

If the opponents interfere above 2, the basic methods of all non-pass actions being natural and GF are back in play.

Delayed Interference:

If the opponents do not interfere in the direct seat, but later in the relay after a GF bid by responder, we use the following methods:

• If the opponents interfere over one of opener's asking bids, responder answers in steps as normal, except that is used for the first step, Pass for the second, and further bids show the 3^rd and higher steps.
• If the opponents interfere over responder's answer, any bid by opener breaks the relay and all subsequent bidding is natural.  A Pass by opener is a relay bid, asking the next question.  Finally, is penalty.