Constructive Overcall Structure Auctions

All the following methods apply when opponents open 1 of a suit.

Contents:

1-level overcalls
No Trump Overcall
Power doubles
Roman Jump Overcalls
Direct cue-bids
Jump cue-bid
Intermediate jump overcalls
4-level overcalls
2N
2-level overcalls
2S/1C
Passed hand modifications
1. 1-level overcalls
  One-level overcalls are extremely aggressive, often 4-card suits, approximately 6-14 HCP. They deny hands suitable for a NTO or a RJO. We do not overcall for no reason, however. We will either have a decent hand, or a decent suit, or a lead-director of some sort.
  Continuations:
  - raises are all blocking/to play (a single raise suggests four trumps, but may be made with 3-card support).
  - A new suit at the 1-level is a 1-round force, either a weak hand with a rebiddable suit, or a "flower bid" (an invitational hand with 3+card support for opener's suit and 4+ cards in the suit bid).
  - 1N is Lebensohl, one of the following hands:
    - a signoff in a suit that is lower-ranking than the overcall.
    - a flower bid in opener's suit (rebid overcaller's suit)
    - an invitation in NT with a stopper (rebid 2N)
    - a choice of games hand (3N or game in overcallers suit - rebid 3N)
  - A new suit at the 2-level is a flower bid
  - A cue-bid is a no-fit invitation.
    Overcaller's step rebid is negative/waiting. His rebid of the overcalled suit shows a weakish hand with a 6-card suit. All other calls are natural and show extras.
  - Jump-shifts are mini-splinters
  - 2N shows opening hand values with 4-card support or better.
    Overcaller's continuations are as follows:
    - A rebid of 3 of the overcalled suit shows a minimum and is very discouraging.
    - Rebids below 3 of the suit are counter-game-tries. They tend to show values in the bid suit.
    - Bids above 3 of the suit show game-going hands. Bids of a new suit show shortness and 3N is choice of games.
  - If opponents bid or make a negative double, we use support doubles/redoubles.
2. No Trump Overcall
  A 1N overcall shows (usually) about 6-14 HCP, with at most 2 cards in opener's suit and at least 3 in every other suit. Some hands stronger than the given range may be treated with a 1N overcall if they are not suitable for other systemic bids. With one of these hands, overcaller must bid again, raising to game, doubling, or cue-bidding.
  Continuations:
  - New suits are natural/blocking at any level.
  - NT bids show the 2 lowest unbid suits.
  - A cue-bid is investigatory. Cue-bidder has an invitational hand or a "choice of preempt" hand. A cue-bid is forcing to the 3-level.
  If the opponents double:
  - A redouble show 4 cards in the highest unbid suit.
  - New suit bids show 5-card suits.
  - A pass denies all of the above. If advancer passes, a redouble by overcaller promises a 5-card suit somewhere.
3. Power doubles
  A double shows 15+ HCP, balanced, or with length in opponent's suit.
  Continuations:
  - Simple new suit bids are weak, may be 4-card suits at the 1-level, tend to be 5-card suits at the 2-level.
  - Jump-suit bids are invitational, show 5+ card suits.
  - NT bids are to play opposite a minimum. 1N is neutral, does not promise any values, and does not promise a stopper. Higher NT bids promise a stopper.
  - A cue-bid is investigatory. It is forcing to game or until a suit is bid twice. It may just be a NT raise without a stopper.
  - 4m is Namyats, showing the corresponding major and some slam interest.
  Opener's rebids are natural and obvious, except that a 2C rebid over a 1-level response is artificial, showing 18-19 HCP.
4. Roman Jump Overcalls
  The cheapest two jump overcalls show approximately 6-14 HCP and at least 5-4 in the overcalled suit and the one directly above (always 5 in the lower-ranking suit- at least 10 cards if at the 3-level). NTO's usually take precedence over RJO's.
  Continuations:
  There are several cases here:
  1. 5-4 Minor-major overcalls (1C)-2D, (1D)-2S, (1H)-2S.
    
    Advancer's calls are as follows:
    (see below for a worked out example)
    - pass, or a simple preference to overcaller's other suit: to play.
    - simple bid in the fourth suit: natural, constructive, non-forcing.
    - 2N: 3 or more cards in the major suit, invite or better. See below for continuations.
    - cue-bid: strong game interest, denies support for overcaller's major. Natural continuations.
    - raises and jump-preferences: preemptive/to play.
    - jump-shift in 4th suit (if not game), jump-cue-bid: shortness, slam interest.
    - games: to play.
    After advancer bids 2N:
    - 3 of our minor shows minimum shape, minimum strength.
    - 3 of our major shows a minimum, but extra length in the major.
    - 3 of "their" minor shows extras and non-overwhelming shape.
      Now simple bids in our suits are non-forcing, while the 4th suit bidding one of their suits is a general force.
    - 3 of "their" major shows a minimum, extra length in our minor, and no extra length in our major.
    - 3N shows extras, a stopper in their suit and denies extra length in our major.
    - bids above 3N show extras, extra shape and are natural in our suits, show shortness in "their" suits.
    Ok, I promised an example. Here goes:
```
(1C)-2D	   
           pass, 2H = preference
           2S = natural, constructive, non-forcing
           2N = 3+ hearts, invite or better
           3C = diamond interest, almost-game-force
           3D,3H,4D = preemptive/to play
           3S,4C = shortness, slam interest
           games = to play
(1C)-2D-(p)-2N
           3C = non-minimum, non-big-shape (3D and 3H are now 
                non-forcing, 3S is a general force)
           3D = minimum, minimum shape
           3H = minimum, 5 or more hearts
           3S = minimum, 6 or more diamonds
           3N = maximum, club stop
           higher = extras , big shape
```
    Finally, the opponents usually are not silent when we RJO. Our agreements are exemplified by the following auctions:
    1. (1H)-2S-(dbl):
      All our calls are on. Pass is a spade preference. Redouble shows a club fit and invitational or better values.
    2. (1H)-2S-(p or dbl)-2N
      (3H)-?
      - pass = denies five spades, minimum
      - double = extras, denies five spades
      - 3S = five spades, minimum
      - higher = promises five spades, extras
  2. RJO that shows both majors (1C)-2H or (1D)-2H.
    
    The continuations are similar, but not identical, to the preceding case. A 2N advance promises 3 or more spades. A cue-bid is invitational or better and suggests hearts.
    It is probably best to give examples for the continuations:
```
(1D) - 2H
             pass, 2S = preference
             2N = invite or better, 3+ spades
             3C = constructive, natural, non-forcing
             3D = invite or better, suggests hearts
             3M = preempt
             games = to play
             4m = shortness, slam try

(1D) - 2H - (p) - 2N
              3C = extras, not big shape
              3D = minimum, 4-6
              3H = minimum, 4-5
              3S = minimum, 5-5
              3N = extras, diamond stop
              higher = big shape, extras

(1D) - 2H - (p) - 3D
              3H = minimum
              3S = extras, extra spades
              3N = extras, NT interest
              higher = extras, big shape
```
  3. 3-level RJO (1H)-3C, (1S)-3C, (1S)-3D
    
    There is much less room to maneuver here. Simple continuations are called for.
    - simple preferences and game bids are to play
    - a raise or jump-preference to 4m is preemptive
    - a cue-bid is investigatory, a stopper ask until proven otherwise
    - a simple bid of the "4th suit" is natural, constructive, non-forcing
5. Direct cue-bids
  A direct cue-bid shows the shape for a RJO but with non-touching suits. It is unlimited.
  Continuations:
  These are similar to continuations after RJO's, with added complications because of the wide range. Overcaller is certainly entitled to act again with extra values even over simple preferences. (in the following, m and M refer to the two suits shown by the cue-bidder, om and OM to the other two suits):
  - 2 of any suit, or minimum response in one of our suits= simple preference, not encouraging.
  - 2N= 3+ likely cover cards, invitational+, most shapes
  - 3m,4m or 3M (if not minimum response)= LTT bid, less than 3 cover cards
  - 3om= game-forcing, agrees m, suggests exploring for 3N or slam
  - 3OM= high-card raise to 4M, forcing passes are now in effect, may have slam interest
  - games= to play, forcing passes are NOT in effect
  Continuations after 2N advance (in the following, mimimum = at least 6-1/2 losers):
  - 3m = minimum shape, minimum strength
    (advancer's bids are now to play)
  - 3om = most non-minimums, but usually 5 or 6 losers
    (3M or 4m are now invites, 3D or 3S (depending on the suits) is a game force and a further inquiry)
  - 3M = minimum strength, but extra length in M
  - 3OM = minimum strength, but extra length in m
  - 3N = about 3-4 losers, denies extra length in M, stopper in their suit
  - 4m = 4 losers or better, likely 4-6 shape
  - 4OM, 4om= at least 5-5 shape, 4 losers or better, void in bid suit
  - 4M = 3 or 4 losers, no void, 5-5 or 6-5
  For responses to 3D or 3S ask see below.
  Specifics:
  1. (1C)-2C
    - 2D,2H,2S: to play
    - 2N: ask, invite+
    - 3C: diamond fit, high-card game force
    - 3D,4D: preemptive
    - 3H: spade fit, high-card game force
    - 3N,5D,4H,4S: to play (may be preemptive)
    After 2N advance:
    - 3C: extras, many shapes (over this, 3D re-ask, 3S and 4D invites)
    - 3D: 4-5, minimum
    - 3H: 4-6 or better, minimum
    - 3S: 5-5 or better, minimum
    - 3N: 3-4 losers, denies 5 spades, club stop
    - 4C: 5-5 or better, club void, at most 4 losers
    - 4D: 4-6 shape, no void, at most 4 losers
    - 4H: 5-5 or better, heart void, at most 4 losers
    - 4S: 5-5 or 6-5, no void, 3 or 4 losers
    after 3D re-ask:
    - 3D: 4-5, 5 or 6 losers, no club stop
    - 3H: 4-6 or better, 5 or 6 losers (or occasionally 3-4 losers, 4-5, no club stop)
    - 3S: 5-5 or better, 5 or 6 losers
    - 3N: 5-6 losers, club stop, denies 5 spades
    - 4C: 5-6 losers, club void, at least 5-5
    - 4H: 5-6 losers, heart void, at least 5-5
    - 4S: 5-6 losers, 6-5 or better, no voids
  2. (1D)-2D
    - 2H,2S,3C: to play
    - 2N: ask, invite+
    - 3D: club fit, high-card game force
    - 3H,4C: preempt
    - 3S: heart fit, high-card game force
    - 3N,4H,4S,5C: to play (may be preemptive)
    After 2N advance:
    - 3C: 4-5, minimum
    - 3D: extras, many shapes (over this, 3S re-ask, 3H and 4C invites)
    - 3H: 5-5 or better, minimum
    - 3S: 4-6 or better, minimum
    - 3N: 3-4 losers, denies 5 hearts, diamond stop
    - 4C: 4-6 shape, no void, at most 4 losers
    - 4D: 5-5 or better, diamond void, at most 4 losers
    - 4H: 5-5 or 6-5, no void, 3 or 4 losers
    - 4S: 5-5 or better, spade void, at most 4 losers
    After 3S re-ask:
    - 3N: denies 5 hearts, 5 or 6 losers, diamond stop
    - 4C: 5 or 6 losers, 4-6 or (4-5, no diamond stop)
    - 4D: at least 5-5, 5 or 6 losers, diamond void
    - 4H: 5-5 or 6-5, 5 or 6 losers, no diamond void
    - 4N: 4-5, 3-4 losers, no diamond stop (likely D stiff, since no power double)
  3. (1H)-2H
    Auctions are analogous to the (1C)-2C case, except that an immediate 3D advance is a simple preference
  4. (1S)-2S
    - 3C,3H: to play
    - 2N: ask, invite+
    - 3D: club fit, high-card game force
    - 4C: preempt
    - 3S: heart fit, high-card game force
    - 3N,4H,4S,5C: to play (may be preemptive)
    After 2N advance:
    - 3C: 5-5, minimum
    - 3D: extras, many shapes (over this, 3S re-ask, 3H and 4C invites)
    - 3H: 6-5 or better, minimum
    - 3S: 5-6 or better, minimum
    - 3N: 3-4 losers, denies 6 hearts, diamond stop
    - 4C: 4-6 shape, no void, at most 4 losers
    - 4D: 5-5 or better, diamond void, at most 4 losers
    - 4H: 5-5 or 6-5, no void, 3 or 4 losers
    - 4S: 5-5 or better, spade void, at most 4 losers
    After 3S re-ask:
    - 3N: denies 6 hearts, 5 or 6 losers, spade stop
    - 4C: 5 or 6 losers, at least 5-5, spade void
    - 4D: at least 5-5, 5 or 6 losers, diamond void
    - 4H: 5-5 or 6-5, 5 or 6 losers, no void
    - 4N: 4-5, 3-4 losers, no spade stop (likely spade singleton since no power double)
6. Jump cue-bid
  A jump cue-bid is stopper asking for NT purposes.
  Advances and continuations are natural.
7. Intermediate jump overcalls
  Any 3-level jump overcall which is not defined as a RJO is an intermediate jump overcall (at least a good 6-card suit and values to compete to the 3-level; some defensive values are expected. Depending on suit length and quality, the HCP range is something like 12+-16).
  Continuations are natural. New suits are forcing.
8. 4-level overcalls
  - A 4m overcall is Namyats, showing a good 4-level overcall in the corresponding major.
    Over this, use your favorite methods. A step advance should be some sort of asking bid.
  - A 4M overcall is preemptive. (4C is preemptive over after a 1H opening bid; so is 4D after a 1S opening).
9. 2N
  A 2N overcall shows a strong (4-1/2 losers or less) 2-suited hand with touching suits (at least 5-4 in theory, but in practice at least 10 cards in the suits).
  Continuations:
  - A return to the anchor suit is weak, preference
  - A bid of the minor of the same color of the opening bid (sounds weird, but it works) is the only way to initiate an asking sequence (it does not necessarily show game interest).
    For responses see below.
    After overcaller has shown his strength and suits, it's important for advancer to know if his cover cards are working. So after the response to the initial ask, the cheapest non-playable step is a shortness ask.
  - A bid in one of overcaller's "optional" suits is weak if
    - it is below 3 of the anchor suit or
    - it is the cheapest such bid available.
    (except for the auction (1D)-2N there will only be one such bid)
  - All game bids (with the exception of 3N) are to play.
  - The three cheapest bids that do not fall under one of the above are splinters in support of the anchor suit.
  - Everything else (there is very little left) is "natural".
  Responses to initial ask:
  The two cheapest steps show a minimum, the next two show extras.
  The second suit is shown "naturally" (if neither of the 2 steps is an "optional" suit, 3N=minors).
  Higher bids show maximums with unusual shape.
  Responses to shortness ask:
  - 1st step= lower shortness
  - 2nd step= higher
  - 3rd step= both
  This is how it works in practice:
  1. (1C)-2N
    (the anchor suit is hearts)
    - 3C= ask
    - 3D= weak, preference
    - 3H= weak, preference
    - 3S,3N(=D),4C= splinters in support of hearts
    - 4D= ????
    - 4H,4S,5C(!!!),5D = to play
    (1C)-2N-3C-?
    - 3D= min, H & D
      (now 3N,4H,5D are to play, 4D = invite, 4C = splinter in support of diamonds and 3S= shortness ask)
    - 3H= min H & S (similar continuations, 4C = shortness ask)
    - 3S= extras H & S (4C = shortness ask)
    - 3N= extras H & D
      (4C = shortness ask; note that 4D is non-forcing over 3N in this auction)
  2. (1D)-2N
    (the anchor suit is spades)
    - 3C= weak, preference
    - 3D= ask
    - 3M= weak, preference
    - 3N (=H),4m= splinters in support of spades
    (1D)-2N-3D-?
    - 3H= min, H & S (4C= shortness ask)
    - 3S= min, C & S (4D= shortness ask)
    - 3N= extras, H & S (4C = shortness ask)
    - 4C= extras, C & S (4D= shortness ask)
  3. (1H)-2N
    (the anchor suit is clubs)
    - 3C= weak, preference
    - 3D= ask
    - 3S= weak, preference
    - 3H,3N(=S),4D= splinters in support of clubs
    - 4C= ???? (RKC in clubs, maybe?)
    (1H)-2N-3D-?
    - 3H= min, C & D
      (3S= shortness ask; note that 4D is to play here; 4C is a mild invite)
    - 3S= min, C & S (4D= shortness ask)
    - 3N= extras, C & D
      (4H = shortness ask, note that 4C is an invite here, and 4D is weak)
    - 4C= extras, C & S (4D= shortness ask)
  4. (1S)-2N
    (the anchor suit is diamonds)
    - 3C= ask
    - 3D= weak, preference
    - 3H= weak, preference
    - 3S, 3N (=H), 4C = splinters in support of diamonds
    (1S)-2N-3C-?
    - 3D= min, C & D (3H=shortness ask)
    - 3H= min, D & H (3S=shortness ask)
    - 3S= extras, D & H (4C=shortness ask)
    - 3N= extras, C & D
      (4H= shortness ask; note again that 4C is weak here, and 4D is an invite)
10. 2-level overcalls
  2-level overcalls are fairly sound from the point of view of playing strength. However, they do not promise any defense: a hand worth a fairly sound preemptive jump overcall in standard will be treated with a simple overcall in OS.
  We like to use Rubens advances and over 2-level overcalls. Note that this is illegal in ACBL events, except for Mid- and Super-Chart events. When that is so, we treat a new suit as a 1-round force, and a cue-bid as a limit raise or better. In the specific auction (1S)-2H, 2N shows a limit raise with 4 or more trumps.
  In any case, jump-shifts are fit-showing.
11. 2S/1C
  Over a 1C opening bid, 2S is preemptive.
  Over this, you can use your favorite methods. For example, 2N could be Ogust, or feature-asking, or maybe asking for shortness.
12. Passed hand modifications
  A double by a passed hand promises the shape/values for a NTO, and promises 4 cards in the highest unbid suit. A NTO by a passed hand denies 4 cards in the highest unbid suit.

Constructive Overcall Structure Auctions

5-4 Minor-major overcalls (1C)-2D, (1D)-2S, (1H)-2S.

RJO that shows both majors (1C)-2H or (1D)-2H.

3-level RJO (1H)-3C, (1S)-3C, (1S)-3D

(1C)-2C

(1D)-2D

(1H)-2H

(1S)-2S

(1C)-2N

(1D)-2N

(1H)-2N

(1S)-2N