Mr. Norman Squire, 1907-1991, of England introduced this convention for the responder and his rebid. The bid by the responder of the only unbid suit at his second turn is a waiting move and promises nothing about the suit itself. The bid of the fourth suit is considered artificial, communicating nothing about the suit itself.
This bid was originally designated, and perhaps more accurately, as Fourth Suit Artificial, but there is practically no bridge player who plays it as non-forcing, and therefore this term has become non-descriptive.
The question, which must be addressed by both partners in their partnership agreement, is whether or not the bid shows length and/or strength in the fourth suit. If the bid is used artificially, the responder usually has 2 or 3 losers in this fourth suit. In this case, the opener should not opt for No Trump unless he indeed has a stopper in this fourth suit.
An example can illustrate the principle:
South West North East 1 Pass 1 Pass 1 Pass 1
743 A75 AQJ3 954
Although North does not possess a 4-card Spade suit, playing the Fourth Suit Bid is forcing for one round only, and promises a minimum of 10-11 points. If, on the other hand, the Fourth Suit Bid is made on the third level, it is considered to be forcing to game. Both partners must agree on this method if they wish to use it.
The concept behind this conventional method is to discover whether there is a fit or whether the partnership should play in No Trump. The following examples should clarify this:
South West North East 1 Pass 1 Pass 2 Pass 3
KQ85 A7 A872 954
As North, the player knows that game is possible. However with only a 2-card Heart suit it would not be suitable to bid game in Hearts. With no stoppers in the Club suit it would not be prudent to bid game in No Trump. Since the partnership is still only on the two level, North knows there is sufficient bidding space to discover more information. By bidding the fourth unbid suit North informs partner that game values are present. This bid of the fourth suit requests additional information from partner.
There are various degrees of concern whether North should, in the above example, bid 3 No Trump on the second bid when holding a single Club stopper or whether it would be more prudent to discover whether partner, by bidding the fourth suit, is able to bid No Trump showing a Club stopper also. This is a matter of partnership agreement.
Note: Fourth Suit Forcing is not employed if one partner is a previously passed hand. This conventional method does not apply under these circumstances.
South has not yet limited his holding and has therefore several options open.
1. With a Club stopper South will bid game in No Trump since there is no known fit. 2. South can infer that North has a 5-card Spade suit and will show support with a 3-card Spade suit. This denies a Club stopper. 3. If South supports Spades showing only a 3-card Spade suit, North can decide to declare game in Spades with a Moysian fit. However, knowing that there is an 8-card fit in Diamonds, North can opt to play in 4. South, with additional values, can raise to game.
These options are shown below:
1. South 2. South 3. North
8 KJ754 KJ106 AQ4
AJ4 KJ762 KJ108 9
KQ85 A7 A872 954 3 NT 3 4
Another feature of this conventional method is to be able to show distribution to partner via the bid of the fourth suit, as illustrated in the following example:
South West North East 1 Pass 1 Pass 2 Pass 3
AQ8754 7 AKJ107 5
South has shown nine of his thirteen cards and both suits in which North has a singleton. North is unable to support either Hearts or Clubs, but must show partner the distribution of at least a 5-5 holding in the other two suits. This action can only occur if North truly has a 5-card suit in the fourth unbid suit since this is not an artificial bid.
This is accomplished by jumping one level when bidding the forcing fourth suit. This jump shows not only a 5-5 shape but also game forcing values. If South then has a 3-card Spade suit, South should support North in Spades knowing that there is a 5-3 fit. If South instead has a 3-card support in Diamonds, then South may decide for a Minor suit game in Diamonds. The third option is to try for nine tricks in No Trump.
If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.