Moscito Byte

GENERAL METHOD: Moscito byte (major-oriented strong club)

General description and suggested defences

TWO OVER ONE: Artificial, or natural nonforcing, depending on sequence

VERY LIGHT: Openings (1st/2nd only)

FORCING OPENING: 1C

NOTRUMP OPENING BIDS

• 1NT: 11-14 HCP (1st/2nd) 13-16 HCP (3rd/4th)
  • Denies 4-card major unless 4333
  • 5-card Major common: No
  • System on: No
  • 2C: Stayman (does not promise 4-card major)
  • 2D: Transfer to H (may be INV, only 4 hearts)
  • 2H: Transfer to S (may be INV, only 4 spades)
  • 2S: 4-4 majors or weak with minors
  • 2NT: Natural, invitational
  • 3C: Transfer to D, weak or 3-suited
  • 3D: Stopper ask
  • 3H: Natural, GF
  • 3S: Natural, GF
  • 4C: Transfer to H
  • 4D: Transfer to S
  • 4H: Natural, to play
  • Smolen: No
  • Lebensohl: No
  • Negative DBL: No
  • Other: Rubensohl (transfers in competition)
• 2NT: 0 to 10 HCP (club preempt, or bad diamond preempt)
• Minor-suit responses: Pass or correct
• Major-suit responses: Natural, forcing if below game
• 3NT: 0 to 10 HCP (minor-suit preempt)
• Minor-suit responses: Pass or correct
• Major-suit responses: Natural, to play

STRENGTH OF NOTRUMP REBIDS

• 1C-P-1D-P-1NT: 14-17
• 1D-P-1H-P-1NT: 12-14
• Other NT rebids: artificial

• 1H: 4+ H, 0-3 S, 8-15 HCP (12-16 3rd/4th)
• 1S: 4+ S, 4+ H, 8-15 HCP (11-16 3rd/4th)
• Double Raise: Weak
• After Overcall: Weak
• Conventional Raises:
• Over 1H: All NT and minor bids, except 2D and 1NT
• Over 1S: 3D, 4D
• 1NT: Nonforcing
• 2NT over 1H: 4+ support, invitational or better, not minisplinter
• 2NT over 1S: Transfer to 3C, either clubs or minisplinter
• 3NT over 1H: Game-forcing raise, minor-suit void
• 3NT over 1S: To play, any strength
• Drury: No
• 1H-1S: Strong, artificial
• 1H-2D: Unbalanced, constructive, artificial
• 1S-2C: invitational raise or GF
• 1S-2D: H signoff, or constructive S raise, or invitational misfit
• Major-suit bids: Natural, nonforcing

MINOR OPENINGS

• 1C: Usually 15+ HCP (17+ 3rd/4th), any shape
• 1D: 4+ S, 0-3 H, 8-15 HCP (11-16 3rd/4th)
• Double Raise: N/A
• After Overcall: Rubensohl (transfers in competition)
• Forcing Raise: N/A
• Frequently bypass 4+ D: yes
• 1NT over 1C: 8+ HCP
• Other responses to 1C:
• 1D: Usually 0-8 HCP, any shape
• 1H, 1S, 1N, 2C, 2D: Artificial, 8+ HCP, shape showing
• 2H, 2S, 3C, 3D: Natural, semipositive
• Others: Artificial semipositives
• Other responses to 1D:
• 1H: Artificial, waiting
• 1S: Artificial, strong
• 1N: Constructive, 5-6 hearts
• 2D: Constructive, 3+ spades
• 2NT, 3C, 3D, 3N, 4C, 4D: Artificial spade raises
• 2C, 2H, 2S, 3H, 3S, 4H, 4S: Natural, nonforcing

OTHER OPENINGS

• 2C 10 to 15 HCP, 6+ clubs or 4=5 minors, no major. Responses: 2D strong+artificial, others mostly natural
• 2D 10 to 15 HCP, 6+ diamonds or 5=4 minors, no major. Responses: 2H strong+artificial, 3C any splinter raise, others mostly natural
• 2H 3 to 9 HCP, natural, usually 6+ hearts. Responses: 2N strong ask, 2S natural NF, 3C/3D transfers, fit-showing jumps
• 2S 3 to 9 HCP, natural, usually 6+ spades. Responses: 2N strong+artificial, 3C/3D/3H transfers, 4C/4D fit-showing

• New Minor Forcing: No
• 4th Suit Forcing: No
• Weak Jump Shifts: In and out of competition
• Rubensohl: Transfers in competition
• No negative, responsive, support or maximal doubles
• Card-showing doubles

NOTRUMP OVERCALLS

• Direct 15 to 18 HCP, system on
• Balancing 10 to 16 HCP
• Jump to 2NT: 2 Lowest

SIMPLE OVERCALL

• 1 level 8 to 16 HCP, 5+ cards
• New Suit: Non-Forcing Constructive
• Jump Raise: Weak

JUMP OVERCALL: weak

OPENING PREEMPTS: light

DIRECT CUEBIDS

• Michaels: over natural openings
• Natural: over artificial openings

DEFENSE VS. NOTRUMP

• 2C: Hearts + another
• 2D: Spades + another
• 2H: Natural
• 2S: Natural
• DBL: Penalty
• Higher Bids: 2NT unusual, others natural

• New suit forcing at the 1 level only
• Jump shift weak
• ReDBL implies no fit
• 2NT over t/o X of Major: Limit+
• 2NT over t/o X of Minor: N/A

VS. OPENING PREEMPTS

• Double is takeout thru 4S
• Lebonsohl 2NT response

SLAM CONVENTIONS: Gerber, RKCB (D0P1)

General Description of Moscito and Best Defenses

System design: Moscito was designed around the idea of getting into and out of the auction quickly, primarily in a major.

The opening bid structure reflects this:
15+ open 1C; all other openings are generally 8-14
both majors open 1S
hearts only open 1H
spades only open 1D
no major, balanced, open 1N (11-14)
no major, unbalanced, open longer minor naturally at 2 level

The basic idea is to determine quickly whether or not game values exist. If so, you explore for game or slam carefully. If not, you find a 7+ card major suit fit and sign off as quickly as possible.

The system is designed to maximize the pressure on the opponents.

Suggested defense: In making the following suggestions, I have tried to cater to the fact that implementing new bidding systems is difficult, and have therefore tried to make suggestions that will allow people to leverage their existing understanding to the maximum extent possible.

Opening bid Suggested defense:

1C treat as strong club
1D X = weak t/o X of 1S, 1S = stronger t/o X of 1S. Other calls unchanged
1H unchanged; probably make t/o X more aggressively than previously
1S unchanged, although you might want to make t/o X guarantee both minors
1N treat as weak NT
2C treat as precision 2C opener, or as weak two
2D treat as weak 2

More sophisticated defenses are certainly possible, especially to 1D.  But remember that this is not a FERT system: 1D isn't a random catchall. It is a very specific hand -- 8-14 HCP, spades without hearts. Its frequency as such is much lower than the 1D bid in a FERT system.

Other defensive remarks: The most important thing is to beef up competitive bidding generally. Playing against Moscito will result in far fewer uncontested auctions than when playing against Standard American.

Later bidding: Many of responder's initial actions are artificial. In most cases, the artificial bids are only made with strong hands, although there are some exceptions (e.g., 1D-1H is a general waiting bid). I would suggest:

1. If responder's action is natural, treat it normally.
2. If responder's action is artificial, pretend that it didn't happen. Double is t/o of opener's known suit, other calls natural.

Again, this is not the best defense possible, but has the advantage of relative simplicity.

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