OKbridge 2/1

Last updated April 28, 2019

OKbridge 2/1 is a duplicate bridge bidding system combining two-over-one game-forcing and Walsh bidding methods.

Duplicate bridge is the most widely used variation of contract bridge in club and tournament play. It is called duplicate because the same bridge deal is played at each table and scoring is based on relative performance. In this way, every hand, whether strong or weak, is played in competition with others playing identical cards, and the element of skill is heightened while that of chance is reduced. Duplicate bridge stands in contrast to rubber bridge where each hand is freshly dealt and where scores may be more affected by chance in the short run.

A bidding system in contract bridge is the set of agreements and understandings assigned to calls and sequences of calls used by a partnership, and includes a full description of the meaning of each treatment and convention. The purpose of bidding is for each partnership to ascertain which contract, whether made or defeated and whether bid by them or by their opponents, would give the partnership their best scoring result.

2/1 game forcing is a bidding system in modern contract bridge structured around the following responses to a one-level opening bid:

a non-jump response in a new suit at the one-level is constructive and forcing for one round,
a non-jump response in a new suit at the two-level is forcing to game, and
a 1NT response is forcing for one round and indicates insufficient values to immediately commit to game or bid a suit at the one-level.

Popular with internet bridge players on the OKbridge website,^[1] this style of 2/1 bidding results from the combination of five bidding conventions and principles. Each takes on a slightly different meaning from those in other bidding systems, but the combination results in a superior description of a hand's high card strength and shape. These principles and conventions are:

Five-card majors is a contract bridge bidding treatment common to many modern bidding systems. Its basic tenet is that an opening bid of one-of-a-major in first and second position guarantees at least five cards in that major. This method has become standard in North American tournament play, but European methods vary.

The forcing notrump is a bidding convention in the card game of bridge.

Walsh is a convention used in the card game of bridge in response to an opening bid of 1♣. The convention has its origins in the Walsh System developed by Richard Walsh.

This system is consistently based on the principle of slow arrival: the stronger the hand, the slower the bidding sequence progresses. Conversely, all jumps will tend to deny strength or act in a preemptive manner to use up bidding space and deny the opponents the opportunity to describe their hands. Unlike most hand evaluation methods, OKbridge 2/1 describe shape and strength separately, i.e. distributional points are not added to high card points.

In the game of contract bridge, the principle of fast arrival is a bidding treatment widely used in game forcing auctions whereby:

In contract bridge, various bidding systems have been devised to enable partners to describe their hands to each other so that they may reach the optimum contract. Key to this process is that players evaluate and re-evaluate the trick-taking potential of their hands as the auction proceeds and additional information about partner's hand and the opponent's hands becomes available.

Five-card majors

This is almost the same as the Five-card majors bidding system used in SAYC. To review, a player must have five cards in hearts or spades to open (along with 12 high card points; the fifth major card is considered to be the 13th point). This often makes it necessary to open the bidding with “one club” in the case of a four-card major even if opener does not have clubs with which to play. Responder of course knows that the “one club” opening bid may or may not suggest clubs as the trump suit, as the priority in duplicate bridge is to find an eight card or longer fit in a major suit (the golden fit), or perhaps a game in notrump. Each partner understands that subsequence bidding sequences will clarify its true meaning.

The Walsh bidding method detailed below will have some impact on the five-card major concept. Unlike SAYC, partners with interest in the majors (four cards in one or both major suits) should always open the bidding with “one club” regardless of the length and strength of the clubs or diamonds in their hand. The opening bid of “one diamond” alternatively denies interest in a major suit.

Rule: only open hearts and spades with five in the suit. With a four-card major, always open “one club."

Bids following the opening bid will clarify if the opening bid suggests clubs as a trump suit or interest in a major. Bids opening “one diamond” are reserved for a good diamond suit with an unbalanced hand and without a four-card major.

The “two over one” game force

This is basically the same as the typical 2/1 game forcing convention, showing game strength but also implies a balanced or semi-balanced hand. It is one of the options in responding to openers 5-card major including:

showing weak support with a direct bid (1♥- 2♥ or 1♠- 2♠) with 6-9 points and 3 card support and an unbalanced hand (see forcing 1NT below);
showing invitational support with a jump bid (1♥- 3♥ or 1♠- 3♠) with 10-11 points and an unbalanced hand (see forcing 1NT below);
using the Forcing notrump response (1♥ or 1♠- 1NT) to show weak or invitational hands with balanced or semi-balanced hands, and
showing strong support with a “two over one” response. When responding to a 5-card major opening bid, a bid at the two-level which is a lesser suit than partners opening bid at the one level (i.e. “two over one”) is a game forcing bid that promises strong support for partners 5-card major. Strong support includes:
- 3-card support and 12 high card points, or
- 4-card support with 6-9 points, or
- 3-card support with 8-9 points and an unbalanced hand.

Examples of a 2/1 response: 1♥ - 2♣; 1♥ - 2♦; 1♠ - 2♣; 1♠ - 2♦; and 1♠ - 2♥. The 2/1 bid shows both game strength (perhaps with slam interest) and also conveys additional information about responder’s hand. Of course, the 2/1 response should never be passed by the opening partner because the next bid by responder will clarify if the responder has support for partners 5-card major.

Rule: Over a 5-card major, a 2/1 bid by an unpassed hand is forcing to game.

The value of the 2/1 game forcing bid is that with the slow arrival concept and early game force, there is a lot of opportunity in the remaining bidding space for both partners to describe their hands and explore for a potential slam. With this opportunity we can find additional slams based on combined points and shape, instead of just on high card points alone. Additional bidding conventions will make this all worthwhile.

Walsh

The Walsh style of bidding stands in opposition to the concept of bidding up the line. With the OK Bridge 2/1 bidding system, use Walsh to show a 4-card major and sufficient high card points to force to game. The Walsh convention is a “one diamond” response to an opening bid of “one club.” The convention is invoked by responder with interest in a major suit game. If responder has a 4 card major without sufficient strength for game, then responder bids that suit up the line (i.e. skips the “one diamond” bid to deny game forcing strength).

The bidding sequence is:

opener bids “one club” as if to say “Partner, I have 12 high card points to open, I deny a 5-card major but might have a 4-card major, and I may or may not have a club suit.”
responder bids “one diamond” as if to say “Partner, I definitely have a 4-card major and enough strength to at least invite you to game or else force you to game, if we find a 4-4 major suit fit.”
opener then has the opportunity to clarify hand shape (after the Walsh 1 diamond response only) by:
- skipping to 1NT to show a balanced or semi-balanced hand. It does not show weak nor does it deny support of partner’s suit or deny a 4 card major. This is not strictly the forcing one-notrump convention of 2/1, but yet is essentially forcing because the Walsh response by partner has already shown game-going points in responders hand, so opener has every reason to expect partner to rebid after 1NT.
- or showing a major suit up the line, which promises 4 cards and an unbalanced hand.

In SAYC, a balanced hand has no voids, no singletons, and at most one doubleton; non-balanced hands include all others. In OK Bridge 2/1, a balanced hand is without voids or singletons: a non-balanced hand has one or more voids or singletons whereas hands with one or more doubletons are considered semi-balanced. Hands with voids or singletons add strength to declarer’s situation, and the ability to show this strength clearly (yet separately from high card points) is of considerable value. For example, in the sequence 1C-1D-1NT, the openers jump to 1NT is showing a balanced hand or semi-balanced hand with 12-14 points (i.e. no voids or singletons). Alternatively, the sequence 1C-1D-1H usually shows 4 hearts with a side singleton or void, and 1C-1D-1S usually shows 4 spades with a side singleton or void and denies 4 hearts. (It shows extra strength and denies a balanced minimum opening hand. These bids are also used with 16 points or more and semi-balanced hands, in which case it is undesirable to show a balanced minimum 1NT, and you also could not open 1NT.)

When responder skips the Walsh “one diamond” response and bids a four-card major, this shows a weak unbalanced hand (usually 6-9 points). If the opener responds to the 1♦ Walsh bid by skipping over the major suits and replies 1NT, then this shows a balanced or semi-balanced hand without additional strength by voids and singletons. With the principle of “slow arrival,” notice how skipping some bids denies some additional strength.

Rule: When partner opens “one club,” respond “one diamond” if you have a four-card major and game interest.

Forcing Notrump

The forcing notrump convention is needed to complete the 2/1 game forcing convention: unlike in SAYC, a bid of one notrump (1NT) by an unpassed hand in response to a five-card major opening does not show a weak hand, does not deny support for partners bid, does not deny a four-card major, and is forcing for one round – opener must bid again.

The 1NT response to partners five-card major opening is a catch all. It denies a game force and tends to deny an unbalanced hand. The purpose of the forcing 1NT bid is to show a balanced (or semi-balanced) hand without enough strength (6-11 points) to respond with a 2/1 bid. The forcing notrump is for both weak and invitational hands but denies any additional strength from the hand shape (i.e. no “shape points”). The next bid will clarify if weak support is available for partners opening bid.

Since the 1NT bid is invoked with both weak and intermediate hands, it is possible for partnerships with two weak hands to get into some trouble. In theory, this is a small price to pay in weak situations relative to the benefits in other situations of showing extra strength from voids and singletons. In practice when the bidding stops at 1NT, the opponents would probably balance the bidding and take over the auction, so very little is given up.

Rule: A 1NT bid over a five-card major by an unpassed hand is forcing for one round.

To summarize, opener bids as follows (very similar to SAYC):

With less than 12 points and a balanced hand, pass;
With 12+ points and a five-card major, open in the major;
With 12-14 points and a four-card major and a balanced or semi-balanced hand, open 1♣ and rebid 1NT (non-forcing);
With 12-14 points and an unbalanced hand, open 1♣ and rebid a four-card major suit if possible (non-forcing);
With 15-17 high card points and a balanced or semi-balanced hand, open with 1NT (non-forcing);
With 15-17 points and an unbalanced hand, open 1♣ and then bid a four-card major suit at the one-level;
With 18-19 points and an unbalanced hand, open 1♣ and then jump to longest suit (forcing);
With 18-19 points and a balanced hand, open 1♣ and then jump to 2NT (forcing);
With 20-21 points, open the bidding with 2NT (forcing);
With 22 points or more regardless of balance, always open 2♣ (forcing).

To summarize responses to partners five-card major opening, options are:

Use 2/1 response with three-card support and game forcing points (occasionally)
Use forcing 1NT with less than game forcing points and a balanced or semi-balanced hand (typical)
Show weak support (a two-bid) or invitational support (a three-bid) with three-card support and unbalanced hand (occasionally)
If an unbalanced hand (void or singleton) and no three-card support, show a good long suit (rare)

New Minor Forcing

The New minor forcing (NMF) convention is invoked by responder after openers 1NT rebid. In the OK Bridge style of 2/1, NMF is a last resort when responder wants to continue looking for a fit. This means NMF is not used in a 1C – 1D sequence (which is Walsh bidding), is not used when opening a 5-card major (where we use the 2/1 game force) or a no-trump opening (where we use Stayman and other conventions).

In OK Bridge 2/1, NMF is used to:

find the 3-5 major suit fit on invitational hands or stronger (i.e. 5 cards in responders hand), or
get to game in notrump, or
to get additional information about openers hand when responder has a very strong hand.

Be careful what other articles you read about NMF: it is a popular convention in several bidding systems but has different use and meaning among the systems. In our system here, NMF is limited and specialized.

Since 1 clubs will often be opened in 2/1, responders rebid of “two diamonds” following openers rebid of 1NT invokes NMF. On occasion, opener will start with 1 diamonds and later rebid 1NT, in which case NMF is invoked by responder by rebidding “2 clubs.”

As responder, your invocation of NMF tells opener you have a 5-card major and enough points (9 to 12) to at least invite game. Responder's follow-up bid shows whether NMF has been used on an invitational hand or whether responder's hand is forcing to game. The only rebids by responder that are not forcing to game are pass, 2NT, or returning to his major suit at the 2-level.

Rounding out the OK-Bridge 2/1 bidding system (i.e. instead of Walsh, 5-card majors, and NT openers), NMF only applies to these six specific bidding sequences:

1C – 1H – 1NT – 2D
1C – 1S – 1NT – 2D
1D – 1H – 1NT – 2C
1D – 1S – 1NT – 2C
1H – 1S – 1NT – 2C
1H – 1S – 1NT – 2D

When responding to partners NMF, it is best to:

(first priority) Show 3-card support for responders 5-card major if possible.
(second priority) Rebid a long suit of your own to play
(last priority) Respond 2NT with nothing else

Rule: As responder, use NMF over openers rebid of 1NT (non-forcing) to show a 5-card-major.

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References

↑ Official OKbridge website

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[1] Official OKbridge website