Blueberry Precision Club is a modernized Precision Club mixing new ideas from BTU. It is a 5-card major strong club system. It is highly experimental and subject to change without notice.

Shared methods

Looking for a chapter that is missing here? These methods are covered in Strawberry Polish Club:

• 1♥, 1♠, 1NT
• Multi 2♦
• Muiderberg 2♠
• Unusual 2NT
• BTU Namyats

Polish 1♥, 1♠, and 1NT ranges are 1 point higher than our 10–15 majors and 14–16 1NT. See opening meanings and ranges in this system.

Notation

This book follows Strawberry Polish Club for hand evaluation, bidding notation, and punctuation in tables and prose.

References

General methods

• Jan Eric Larsson. Good, Better, Best: A comparison of bridge bidding systems and conventions by computer simulation. ISBN 978-1771402415
• Thomas Andrews. Thomas’s Bridge Fantasia
• Bridge Base. GIB Bid Descriptions

Precision Club

• Adam Meyerson and Samuel Ieong. IMprecision
• Daniel Neill. Standard Modern Precision: Getting from Here to There. ISBN 978-1771401791
• Edward Piwowar. PC - Meckwell Lite Precision Club

Other strong clubs

• Arturo Franco, Marco Pancotti, and Daniel J. Neill. Blue Team Club
• Jan Eric Larsson, Anu Uus, and George Wang. Kaninklöver / Cottontail Club: A Cheatsheet (2022)
• Bo-Yin Yang. Terrorist’s Moscito, or Major-Oriented Strong Club, with Interpid Two Openers

Openings

The notrump ladder

• 11–13: 1♦
• 14–16: 1NT
• 17–19: 1♣ - 1♦ - 1NT
• 20–23: 1♣ - 1♦ - 1♥ - 1♠ - 1NT
• 24+: 1♣ - 1♦ - 1♥ - 1♠ - 2NT

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.

Negative 1♦

Relay structure from Viking Precision 2007 nest very strong hands into 1♣ - 1♦ - 1♥. This treatment rescues the 2NT opening from the notrump ladder and frees 2NT up for preemptive uses.

In Viking:

• 1♠ is 4–5♠, and replies are defined from pass up to 4♣♦ splinters.
• 1NT is 16–19, with its own relays, transfers and slam tries.
• 3♥ is (6=♥, 5=♠).
• 3♠ is 6+♠ with nine tricks.
• 3NT is to play.

Viking 2♠ can also be 46(xx), and 2NT asks which.

Strong 1♥

Viking 2♣ is balanced 4–7.

Negative 1♠

Viking rebids here show strength alone: 1NT 20–21, 2♣ 22+ with steps for responder’s points, 2NT 24–25, 3NT 26–27, 4NT 28–30 and 5NT 30–32.

Positive major 1NT

When several rows fit a hand, the row for its longest suit applies.

These relays are Viking, with the 7-card major steps written out.

Responder has spades

Spades 1♥

1♣ - 1♥ shows 5+♠, or BAL 13+ without a 5-card major. Opener relays with 1♠.

Viking card lists 3♣ and 3♦ as (5=♠, 5=♣) and has no bid for (5=♠, 5=♥). It also lists 3♠ as 12+, but its 2♣ - 2♦ - 3♠ shows the same (6=♠, 5=♦).

The balanced 1NT relays as 1♣ - 1NT does.

Strong 2♣

Opener relays with 2♦ and responder gives the 8–12 answers, except for 5♠ with a minor.

Minor 2♦

Hearts or balanced 2♥

The same relay serves 8–12 and 13+, which bid 2♥ at the same level.

One-suited 2♠

The same relay serves 8–12 and 13+, which bid 2♠ at the same level.

Two-suited 2NT

2NT shows 6+♠ with a 4-card minor, or 55(xx). Opener relays with 3♣ to ask which.

Hearts 1♠

1♣ - 1♠ shows 5+♥ and a shorter spade suit. Opener relays with 1NT.

Viking has 3♦ at 8–12. I adjusted it here to 13+ because 2♦ already handles 8–12 well.

Strong 2♣

Opener relays with 2♦ and responder gives the 8–12 answers, except for 5♥ with a minor.

Minor 2♦

Spades or balanced 2♥

The same relay serves 8–12 and 13+, which bid 2♥ at the same level.

One-suited 2♠

The same relay serves 8–12 and 13+, which bid 2♠ at the same level.

Two-suited 2NT

2NT shows 6+♥ with a 4-card minor. Opener relays with 3♣ to ask which.

Balanced 1NT

1♣ - 1NT shows BAL 8–12 without a 5-card major. BAL 13+ responds 1♥ and rebids 1NT over the 1♠ relay. Both relay with 2♣ to the same answers.

From 3♣ up, responder bids the suit where 3344 is a card short.

Note

I invented these response steps. Viking has a different table.

1♣ - 1NT - 2♣ -	Viking Precision 2007
2♦!	12–14, then the rest one step higher
2♥	4=♥, 2–4♠
2♠	4=♠, 2–3♥
2NT	no 4-card major or 5-card minor
3♣♦	5=#, (5332)
3♥	2245
3♠	2254
3NT	3334

Spades 2♦

Hearts 2♥

Clubs 2♠

Diamonds 2NT

Minors 2♣♦

1♣ - 2♣ shows 5+♦ and 1♣ - 2♦ shows 5+♣, no 5-card major. A 4-card minor beside it responds 2♥ and (5332) responds 1NT, so these hands hold a 4+ major or a one-suiter with no 4-card suit. Opener relays with the next step.

With 13+, responder bids the shape at once. With 8–12, responder bids the cheapest step and, after the next relay, the same shape one step higher.

Viking 2♣♦ allow a second 4+ minor, and its opener may bid naturally instead of relaying.

Diamonds 2♣

Viking shows 6 or 7 cards before strength and resolves 6331 and 7330 to the exact shape, here and over 2♦.

Viking separates a 6-card minor with 4 in the major from one with 5, here and in the other major branches.

Clubs 2♦

Competing through (2♣)

Interference over 1♣ starts from Viking Precision 2007 but keeps new suits natural.

I used to frown at forcing passes, but not anymore. The strong 1♣ is unbounded in strength and shape. Using the double as a brake lets the 1♣ opener describe their hand in layers, something a limited 1NT opener never needs. Responder doubles with nothing and passes with middling values or a trap. Opener usually reopens with a relay double.

• Pass: forcing, 5–7 or a trap pass
• Double: negative, 0–4
• 1NT: forcing to game with a stopper
• Cuebid: forcing to game without a stopper
• Jump cuebid: usually the highest two-suiter
• 2NT: some other two-suiters

The notrump bids shift up over (1NT) and (2♣), as their tables show.

In Viking:

• Pass is 6–8 with 4 cards in an unbid major, or a penalty pass.
• Double is 0–5.
• Over (1♥) through (2♣), new suits are transfers, invitational or slam tries.
• 2NT, or 3NT over (2♣), is 5-5 with 5–7.
• One 3-level bid shows 4441.

Over non-transfer overcalls

Overcalls with no anchor suit are treated as natural because advancer passes with that suit. The trap pass is still meaningful in holding strength and their suit.

Viking keeps its system on over (X) and (1♦). I don’t. These principles work at every level, and decent opponents put their strong hands into (X) and (1♦), which is where the uncontested system is least effective.

The only non-forcing pass is (X) P. Opener may sit for 1♣x, which may produce 200+ points in reasonable circumstances.

We drop club two-suiters over a double because they can be rebranded as traps.

Viking keeps its transfer positives and relays here, and its pass is 6–8 of any shape.

Over (1NT), the two cuebids are 2NT and 3NT. There is no longer a reason to drop club two-suiters. A Wilkosz-like 2NT must be game-forcing for enough space.

Opener tries to declare suit contracts after a notrump cuebid.

Over (2♣), 2NT shows the stopper, so 3NT takes over the two-suiters.

Over transfer overcalls

Transfer overcalls are too many to enumerate, so two rules cover them all.

• The suit they show is the cuebid. Stoppers and trap passes refer to it.
• The suit they name is natural for us, like any other new suit.

The cuebid now comes a level lower, and its cheapest bid is the stopperless game force. Wherever the jump cuebid falls below 2NT, the useful space principle swaps their roles:

• 2NT: unusual, the lowest two suits
• Jump cuebid: some other two-suiters
• The rest follows the non-transfer overcalls.

TRAP serves as the model, where (X) shows hearts and (1♦) shows spades. (X) P stays non-forcing, though advancer seldom leaves 1♣x in.

Competing over (2♦♥♠)

Pass and double keep their meanings from the lower overcalls. Responder still passes with middling values or a trap and doubles with nothing.

Rubinsohl replaces everything but the pass and the double. A transfer shows the suit at once and leaves its strength for later, so one bid replaces both the invitational new suit and the slam-try jump. The strong hand also declares.

Suits still available at the 2-level stay natural and non-forcing, which makes transfers to them forcing to game. Opener completes an invitational+ transfer only with a hand that would pass the invitation.

Viking plays 2NT natural here and transfers at the 3-level that only invite. It also defines responses over (2NT), which Blueberry does not.

Against (2♠), swap 3♥ and 3♠ as in Larry Cohen so that opener declares hearts.

Over transfer overcalls

Rubinsohl reads the suit they show, not the bid they make. Every bid from 2NT through 3♥ transfers to the next suit, and 3♠ transfers to 3NT or 4♣. The transfer into their suit is Stayman. A transfer to a suit we could bid at the 2-level is forcing to game, and any other is invitational or better.

A transfer overcall therefore takes the table of the suit it shows. (2♦) showing hearts follows the (2♥) table, and (2♥) showing spades follows the (2♠) table, swap included. The only new bid is their suit at the 2-level. As over the lower transfer overcalls, it is the cheapest cuebid, a game force without a stopper.

Catchall 1♦

Wilkosz defense

Caution

Wilkosz is originally an opening. Its brown sticker status carries over to this overcall if over a natural opening. This defense is legal only when any of these holds:

• The event permits brown sticker methods, or
• Our 1♦ opening is classified as artificial.

The latter is contested. See my research notes on possibly-void Precision 1♦ precedents.

I still suggest Wilkosz 2♦ even though I regard our 1♦ opening as natural. Wilkosz covers 5 of the 6 possible two suiters. I prefer it against nebulous minor suit openings, but it calls for the legal precautions above.

There are two kinds of choice of games:

• 4♣ by strength
• 4♦ by distribution

Such distinction helps judging how to react to interference. Besides, 4♣ lets the strong hand declare. On the other hand, 4♦ closes the auction ASAP.

Precision 2♣

The 2♦ relay

The 2NT puppet

Competitive bidding

Lyric 2♥

The related 2♦={both majors} opening is known as Ekren or Ekrens after the Norwegian grand master who invented it. Bjørn Olaf Ekren prefers the 2♦ incarnation should not bear his name.

—Bridge: 2♥ as weak in both majors, Chris Ryall

I prefer BTU Terrorist’s continuations.