====== Iancu - Agica system notes ======

♣ ♦ ♥ ♠

===== Introduction =====

This document aims to provide a complete explanation of the MOSCITO bidding system used by Stefan Iancu and Bogdan Agica. It is mainly based on Richard Willey's and Paul Marston's system old-notes, which have provided invaluable help.

The MOSCITO bidding system was designed to support a "Quick in - quick out" auction style. We find that placing most hands in a playable contract as quickly as possible is providing a significant tactical advantage.

Most constructive bidding is based on relays, which are designed to make the unknown hand the declarer in ~90% of the time. It's anchored by a strong club (15+ HCP) opening, which makes room for light, constructive and descriptive opening bids.

Transfer opening bids are used (1♦ -> ♥, 1♥ -> ♠, 1♠ -> ♦), in order to ensure the comparatively well-defined hand is exposed in the dummy.

===== Opening bids =====

Balanced hands open at least 10HCP, only with lead directing purposes.
Adjustments for wildly unbalanced hands will be taken into account, e.g. Kxxxx / Kxxxxx / xx / - is an opening hand.

^ Opening bid                ^ Meaning                    ^ 3rd/4th Position          ^
| [[old-notes#opening_bid|1♣]]            | 15+ HCP, any distribution  | 17+ HCP, any distribution |
| [[old-notes#section|1♦]]            | 4+♥, ♥>♠, 8-14 HCP         | 10-16 HCP                 |
| [[old-notes#section1|1♥]]            | 4+♠, ♠>♥, 8-14 HCP         | 10-16 HCP                 |
| [[old-notes#section2|1♠]]            | 4+♦, either 6♦, or 5-4 minors, could have 6♦4M  | 10-16 HCP                 |
| [[old-notes#nt|1NT]]          | 12-14 BAL or SEMIBAL, no 5+M  | 13-16 HCP                 |
| [[old-notes#section3|2♣]]            | 6+♣, could have 4M, 8-14 HCP  | 10-16 HCP                 |

===== Limited opening bids =====


==== 1♦ ====

The 1♦ opening bid promises at least 4 ♥, hearts longer than spades, and roughly 8-14HCP. It could be balanced, with at least 10 HCP...

=== Raise structure: ===
^ Bid          ^ Meaning   ^
| 4♥           | To play. Could be anything.  |
| 4♦, 4♣, 3♠   | SPL, 4+H   |
| 3♥           | Value raise. 6-10HCP, 4+H, good ODR  |
| 3♦, 3♣, 2NT  | Fit-showing jumps. 4+♥, 5+suit (2NT -> ♠)  |
| 2♥     | 3+♥, 6-10HCP, 4♥ if low ODR  |

=== Other bids: ===
| 2♠  | INV, 5+♠, 5+m  |
| 2♦, 2♣, 1NT  | NAT, NF  |
| 1♠  | NAT, F1  |
| 1♥  | Relay  |

=== Relay structure: ===
:!:

1♦ - 1♥:
^ Bid   ^ Meanings                                                                                 ^^^^^^
| 1♠    | 0-3♠, BAL or 3SUIT or 5♥ + 4+♣                                                           |||||| 
| 1NT   | 44♥♠ BAL or 3SUIT                                                              ||||| Relay    |
| 2♣    | ♥+♦                                                                    |||| Relay  | FIXME    |
| 2♦    | ♥ 1SUIT                                            ||| Relay              |        | FIXME    |
| 2♥    | Reverser 4♥ + 5+♣                        || Relay    | Reverser 4♥ + 5+♦  |        | FIXME    |
| 2♠+   | ♥+♠ 2suit              | Relay -> 2SUIT   | ->1SUIT  | 55♦+♥, etc         |        | FIXME    |
| 2NT+  |                        |                  |          |                    |        | BAL (2NT 5332, 44♦♥, 2434, 3424)  |

==== 1♥ ====

The 1♥ opening bid promises 4+♠ , spades longer than hearts, and roughly 8-14 HCP.

=== Raise structure: ===

^ Bid     ^ Meaning                       ^
| 4♠      | To play. Could be anything.   |
| 4♣♦♥    | SPL                           |
| 3♠      | Value raise. 4+♠, ~6-10HCP, good ODR  |
| 3♣♦♥    | FSJ. 5+ cards, 4+♠, INV       |
| 2♠      | 3+♠, ~6-10HCP. Low ODR if 4♠  |

=== Other bids: ===

^ Bid   ^ Meaning          ^
| 2NT   | INV, 5+♥ + 5+m   |
| 2♣♦♥  | NAT, NF          |
| 1NT   | NAT, NF          |
| 1♠    | Relay            |

=== Relay structure after 1♥ - 1♠: ===
:!:

^ Bid      ^ Meanings                                                                                             ^^^^^
| 1NT      | BAL or 3SUIT or 5+♠ 4+♥                                                                              |||||
| 2♣       | ♠+♦ [[Two_suited|2SUIT]]                                                     |||| Relay                  |
| 2♦       | 5+♠ 4+♣ [[Two_suited|2SUIT]]                             ||| Relay              | BAL                    |
| 2♥       | Reverser 4♠ + 5+♣                            || Relay      | Reverser 4♠ + 5+♦  | 3SUIT with ♥ shortage  |
| 2♠+      | ♠ [[Single_suited|1SUIT]] | Relay -> [[Two_suited|2SUIT]]| | ♦+♠ 2SUIT      |5+♠ 4+♥ [[Two_suited|2SUIT]]|

== Three-suited hands with minor shortage ==
There are two patterns to worry about (5=4=0=4 and 5=4=4=0). They are resolved with a 3NT bid, either through 2NT (high shortage) for 5=4=0=4, or directly for 5=4=4=0. The 7-4-2-0 distribution is therefore displaced a step.

== Balanced hands ==
Balanced hands are shown with a 1♥ - 1♠(R) - 1NT - 2♣(R) - 2♦ development. After the 2♥ relay, the whole structure is downshifted a step, due to the lack of 4♥ in opener's hand. Thus:
^ Bid  ^ Meaning  ^
| 2♠   | 5332     |
| 2NT  | 4♦4♠(32) |
| 3♣   | 4=2=3=4  |
| 3♦   | 4=3=2=4, zoom  |

==== 1♠ ====

The 1♠ promises at least 4+♦, either 5-4 minors either way, or 6+♦, and roughly 8-14HCP. It could hold 6+♦ + 4M.

=== Raise structure ===
^ Bid         ^ Meaning                     ^
| 3♥, 3♠, 4♣  | SPL, 4+♦                    |
| 3♦          | Value raise, ~6-9 HCP, 4+♦  |
| 3♣          | P/C to better minor         |

=== Other bids ===

^ Bid         ^ Meaning                     ^
| 2NT         | FIXME                       |
| 2♥, 2♠      | NAT, NF, 6+ cards           |
| 2♦          | 5+♠, F1                     |
| 2♣          | 5+♥, F1                     |
| 1NT         | Relay, not necessarily strong  |

=== Relay structure ===

The 1NT response to 1♠ is F1, however not necessarily strong. After that:

^ Bid     ^ Meanings                          ^^^
| 2♣      | 5-4 minors                        |||
| 2♦      | 6+♦        || To play               |
| 2♥      | 6+♦ + 4♥    | Relay     | Relay     |
| 2♠      | 6+♦ + 4♠    | -> [[Single_suited|1SUIT]]  | -> [[Two_suited|2SUIT]]  |

==== 1NT ====

The 1NT opening bid promises 12-14HCP and a BAL or SEMIBAL distribution. It cannot contain a 5M. The system is fairly relaxed on whether to open 1NT with 1 or 2 4M.

=== Choosing whether to open 1M or 1NT ===
With a good 4M, especially with a small doubleton, it's advisable we open 1♦ or 1♥. Always open 1NT with 4333.

=== Response structure ===


FIXME

==== 2♣ ====

The 2♣ opening bid promises 6+♣, 0-3♦, 0-4M, and roughly 8-14 HCP.

=== Response structure ===
^ Bid     ^ Meanings     ^^
| 2D      | Relay        ||
| 2♥, 2♠  | F1, NAT      | 6+♣ + 4M  |
| 2NT     | BAL, INV     | -> [[Single_suited|1SUIT]]  |
| 3,4,5♣  | PRE          |           |

===== 1♣ opening bid =====

The 1♣ opening bid is the cornerstone of the system. It shows ~15+ HCP (~17+ HCP in 3rd/4th POS). We tend to upgrade very distributional hands, and to downgrade bad balanced hands.

The response structure is based on a negative 1♦ response and transfer canape responses. Any step that is omitted denies the actual significance of that step. E.g. 1♣ - 1♠ (4+♥, UNBAL, POS) denies the significance of 1♣ - 1♥ (4+♠, UNBAL, POS), therefore implies 0-3♠.

==== Response structure ====

^ Bid    ^ Meaning                                                        ^^^
| 1♦     | Negative, 0-7HCP or 0-1CTRL, any distribution                  |||
| 1♥     | 4+♠, UNBAL, could have longer suit, could be 3SUIT with ♥+♠+m  |||
| 1♠     | 4+♥, 0-3♠, UNBAL, could have longer suit                                                           || Relay                          |
| 1NT    | Any [[Balanced_structure|BAL]], POS (4333, 4432, 5332)         | Relay                              | 4+♥, 4+♠, 2SUIT or 3SUIT       |
| 2♣     | 4+♦, either 1SUIT, or 3SUIT with ♣+♦+M                  | 4+♥, 4+♦, [[Two_suited|2SUIT]]            | 4+♠, 4+♦, [[Two_suited|2SUIT ]]|
| 2♦     | 6+♣, [[Single_suited|1SUIT]]                            | 6+♥, [[Single_suited|1SUIT]]              | 6+♠, [[Single_suited|1SUIT]]   |
| 2♥+    | ♣ + ♦, [[Two_suited|2SUIT]]                             | 4+♥, 4+♣, [[Two_suited|2SUIT]]            |                                |

===== Higher opening bids - preempts =====

==== 2♦ ====

==== 2♥ ====

==== 2♠ ====

==== 2NT ====