===== Balanced structure =====

This structure comes into play whenever the bidding goes 1♣(!) - 1NT - 2♣(R) ,  or via a reverse relay method like 1♣ - 1NT - 2♦+ . Relevant parts of the structure are also used in relay methods after limited openings (1♦ and 1♥).

^ Bid  ^ Meaning                                                                                                                           ^^^^^^^^^^
| 2♣   | Relay, entry point                                                                                                                ||||||||||
| 2♦   | 4+♥                                                                                                                               ||||||||||
| 2♥   | 4+♠                                                                    ||||| Relay                                                      ||||
| 2♠   | Any 4333                                      ||| Relay                   || 4♠4♥ (32)                                                  ||||
| 2NT  | 5♦(332)                       || Relay          | 5♠(332)                 || 5♥(332)                                     ||| Relay         |
| 3♣   | 4♦4♣(32)      | Relay          | 4=3=3=3        | 4♦4♠(32)                || 4♦4♥(32)                     || Relay         | 4=4=2=3       |
| 3♦   | 2=3=3=5       | 2=3=5=3        | 3=4=3=3        | 4=2=3=4       | Relay    | 2=4=3=4       | Relay         | 2=5=3=3       | 4=4=3=2, zoom |
| 3♥   | 3=2=3=5       | 3=2=5=3        | 3=3=4=3        | 4=3=2=4, zoom | 4=2=3=4  | 3=4=2=4, zoom | 2=4=4=3       | 3=5=2=3       |               |
| 3♠   | 3=3=2=5, zoom | 3=3=5=2, zoom  | 3=3=3=4, zoom  |               | 4=3=2=4, zoom  |         | 3=4=4=2, zoom | 3=5=3=2, zoom |               |

Aide memoire: all 5332 shapes are shown with a 2NT bid, and resolved from 3♦ (clubs implicit). All 4333 shapes start with 2♠. All 3♣ bids are 4432.

==== Relay breaks ====
Relay breaks after 1♣ - 1NT imply a minimum balanced hand (15-17HCP). The responder should break the relays to 2NT with any hand that doesn't see any better contract than 3NT, but possibly lacks stoppers in a suit (minimum misfitted hand). Any subsequent bid is semi-NAT, showing a stopper in the suit. This is the only possibility we could retreat to 4 minor to play.