Strong 1♣

Blueberry responds to 1♣ with the transfers of Viking Precision 2007: each positive from 1♥ to 2♦ shows the other suit of its rank. See transfer positives for how the strong hand comes to declare and how the relays fit together.

Transfer positives

The longest suit decides the response. Equal majors respond 1♥, and a major beats a minor of equal length. A (5332) hand responds in its 5-card major, otherwise 1NT, so a minor positive never holds (5332). A 4-card minor beside a 5+ minor responds 2♥, so a minor positive never holds a second minor either.

Opener relays with the cheapest bid. The relays 1♠ and 2♦ bid responder’s suit, and the 1♣ opening already bid clubs, so the strong hand declares those three suits however the relay ends.

Responder’s strength is 8–12 or 13+. Over a major, 13+ bids 2♣ after the relay and then gives nearly the same shape answers as 8–12 does directly. Over a minor, 13+ bids its shape at once, and 8–12 bids the cheapest step and gives the same shape one step higher after the next relay.

Deviations from Viking Precision

These chapters mention where the Viking card differs, right under the tables concerned. Where Viking goes on to ask for aces, controls or the rest of the shape and these chapters stop, Blueberry has no agreement yet.

Viking positives are 8–11 or 12+, and balanced hands respond 1NT through 14. Blueberry splits at 12 and 13, so 1NT stops at 12 and BAL 13+ responds 1♥.

Relay lattices

Each lattice in these chapters maps every shape still possible at that point of the relay to its bid, one lattice per length of the suit in its corner label. Of the other three suits, the highest ranking grows upwards, the next down-left and the lowest down-right. A lattice on a single line is laid flat, and its label also names the second suit it fixes. Borders mark where the bid changes. relay.py draws them and checks that no shape is missed or claimed twice.

Minors 2♥

Viking 2♥ is exactly 5-4 in the minors, and its 2♣ and 2♦ take 5-5 and 6-4.

Three-suited 2♠, 2NT

Opener relays for the singleton.

Viking answers these relays in steps instead of naming the singleton.

Solid suits [3♣ .. 3NT]

Responder’s suit is the trump suit, and the strong hand declares it after the transfer. Opener’s 3NT and four of the suit are to play, and 4NT asks for key cards. Opener’s cheapest other bid relays for shortness, and responder bids the short suit. Shortness in the relay suit goes to the cheapest notrump, and with two short suits responder shows the lower. Without a short suit, responder bids 3NT, or the trump suit once 3NT is gone.

Over 3♣, the relay asks the suit first. The answers are the semi-solid bids one step higher, and the shortness relay then follows the same rule.

In Viking:

• 3♣ is any solid 6-card suit.
• 3♦ is any solid 7+ suit.
• 3♥ .. 4♣ are the semi-solid suits.
• Shortness relays are answered in steps.