Strong Club Systems: Precision, Blue Club, Moscito and More

A strong club system opens 1♣ with every strong hand, usually 16 or more points, and uses all the other openings for limited hands. The 1♣ bid is artificial: it says "I have a big hand" and nothing about clubs. Because the strong hands are taken out, every other opening has a ceiling, typically 15 points.

That one idea has produced a whole family of systems: the Vanderbilt Club of the 1920s, the Italian Neapolitan and Blue Club systems, Precision, Moscito and the relay systems of today. "Big club" is simply the everyday nickname for the strong 1♣ opening. This guide explains how they work, how they differ from each other, and when a strong club beats natural bidding.

Every strong club system rests on three agreements:

1. 1♣ shows the strong hands and is forcing. The threshold varies: 16+ in Precision, 17+ in the Blue Club, about 15+ in common Moscito versions.
2. Responder's cheapest reply, usually 1♦, is the negative. Most other replies are positive, and in many systems a positive response is already a game force.
3. Every other opening is limited. A 1♥ or 1♠ opening has a known top, often 15, so responder can judge quickly.

How often does the strong club come up? We computed the exact odds for a random hand: 16 or more points: 9.8%. 15 or more: 14.2%. 17 or more: 6.4%. For comparison, a natural strong 2♣ of 22 or more: 0.4%. So a 16+ strong club appears about once every ten hands you deal, while a natural 2♣ appears about once in 240. That gap is the whole argument for the strong club: the big hands are common enough to deserve the cheapest, roomiest opening. See what a 1♣ opening means in Precision, Polish Club and three natural systems.

Where the strong club wins: on slam hands, where the low start and early game force give room to exchange information; on part-score hands, where every opening is limited and responder can stop fast; and on hands where the opponents stay out of the auction.

Where natural bidding wins: when the opponents preempt over a strong 1♣, when the catch-all 1♦ meets interference, and in casual partnerships, where fewer agreements mean fewer accidents. For a natural framework, see 2/1 Game Force and the strong 2 clubs opening it uses.

The first strong club. Harold Vanderbilt, who also devised the scoring of contract bridge, published it in his 1929 book Contract Bridge. His 1♣ showed a strong hand, measured in quick tricks, and 1♦ was the artificial negative, the same skeleton strong club players use today. He published an updated version in 1964 with modern point count. In the United States, Howard Schenken later played a strong club that stayed close to the Standard American bidding of its time.

Italy's Blue Team dominated world bridge from the late 1950s into the 1970s, and strong clubs were part of the reason. The Neapolitan Club came first; Benito Garozzo then developed the Blue Club. Its 1♣ promised 17 or more points, and responder answered by controls (ace = 2, king = 1) rather than by suits. In the classic scheme, 1♦ showed 0-5 points, 1♥ showed 6-12 with no more than two controls, 1♠ showed three controls, 1NT four controls, and so on. The other one-level openings showed 12-16 with four-card suits in canapé style: opener often bid the shorter suit first and the longer suit second.

Giorgio Belladonna and Walter Avarelli built the Roman Club in the 1950s, but its 1♣ was not a pure strong club: it covered balanced 12-16 hands as well as some strong ones. That makes it a "small club" system, an ancestor of the ambiguous clubs that mix a weak and a strong option.

C. C. Wei's Precision, made famous by Taiwan's second places in the 1969 and 1970 Bermuda Bowls, is the best-known strong club in the world today: 1♣ shows 16+, everything else is 11-15, five-card majors, a 13-15 or 14-16 notrump, and the special 2♣ and 2♦ openings. The full system is in our Precision Club guide.

Moscito was created in 1985 by the Australian experts Paul Marston and Stephen Burgess. The name is usually expanded as "Major Oriented Strong Club, Intermediate Two Openings" (the authors also offered "In Trouble Often"). Its trademarks: a strong 1♣, a "majors first" style that opens a four-card major ahead of a longer minor, transfer openings in later versions (1♦ shows hearts, 1♥ shows spades), and relay methods for slam bidding. Marston has said they moved to Moscito from a strong pass system after the World Bridge Federation tightened its rules on such systems. Versions differ a lot, so ask for the system notes when you play against it.

Polish Club is a close relative rather than a pure strong club. Its 1♣ shows a balanced 12-14, a natural club hand of 15-17, or any hand of 18 or more. Because the weak option is in there, the opponents cannot simply assume the opener is strong, which takes away the strong club's best-known weakness.

Relay systems take the strong club idea furthest. After 1♣ and a positive response, one player keeps making the cheapest bid (the relay) and the other describes shape and strength in fixed steps, until the relayer knows the hand almost card for card and places the contract. They are very accurate when the opponents stay quiet and need a lot of memory work, which is why you see them mainly in long-standing expert partnerships.

Strong club systems answer 1♣ in two main ways. Take this responder's hand: ♠K8 ♥A752 ♦Q1063 ♣974. It has 9 points and three controls (the ace counts two, the king one).

• Precision (points and suits). 9 points is a positive. With no five-card suit and a balanced shape, the classic reply is 1NT, showing 8-10 balanced, and the side is in a game force.
• Blue Club (controls). The reply is 1♠, showing three controls. Opener learns at once how many aces and kings are missing, which is what matters most for slam.

Points-first schemes are easier to learn and better for finding the right game; control-first schemes are better for slam decisions. Many modern pairs mix the two, for example showing controls only after a game force is set. You can look up the 1NT positive response to a Precision 1♣ to see the robots' version.

North has 20 points and South 13, 33 between them, with a nine-card spade fit. In Precision, South's 1♠ positive tells North three things at once: 8 or more points, five or more spades, and a game force. North holds four of the five key cards and needs to know about the fifth, so North asks with 4NT. South's 5♦ shows one key card (in the common 0314 responses), and North bids 6♠. Count the top tricks: five spades, three hearts, two diamonds and two clubs make twelve.

A natural system gets there too: North opens 2NT (20-21), South transfers to spades and then explores. The difference is room. The strong club auction agreed the suit and set up the force at the one level, so North could take control two rounds earlier. On harder slam hands, that extra room is where strong club pairs gain their IMPs.

When the opponents open a strong 1♣, they hold most of the points, so your side rarely has game. Your goals are to take away their bidding space and to find a cheap sacrifice or a part score when the cards allow it. Practical rules:

1. Come in fast and with shape. An overcall at the one or two level, or a jump, costs the strong side room exactly when it needs it most.
2. Use a two-suited defense. A common one is Mathe: a double of 1♣ shows both majors, 1NT shows both minors, and suit overcalls are natural.
3. Watch the vulnerability. Not vulnerable against vulnerable, a sacrifice over their game is often cheap; vulnerable against not, be careful.
4. The negative response is a second chance. After 1♣ - 1♦, you know opener is strong and responder is weak, so a bid by you is safer than it looks.

A strong club rewards practice. If you and your partner play often, enjoy agreements and like accurate slam bidding, Precision or a similar system will pay you back. If you play with many different partners, a natural system is the safer default, because every agreement you do not share is a chance for a disaster.

A middle path many pairs take: learn a natural system first, then add a simple strong club with your regular partner. For a broader comparison, see the bridge bidding system guide, bridge bidding systems compared and the best bridge bidding system for you.

Strong club bidding becomes natural only after a few hundred hands. In the Bidding Room on BridgeDummy, you can set your side to Precision or Polish Club and bid random deals as South with a robot partner. Tap any robot call to see what it meant. After the auction, your contract and the other reachable contracts are solved double dummy on up to 20 layouts that fit the bidding, so you see the average score of each one next to yours. Set the opponents to Precision instead and you get practice at competing against a strong club.

To work on defense, open the Lead Gym and set the declaring side's system to Precision: the robots bid a random deal and you choose the opening lead after a strong club auction.