Bridge Conventions

Rule of Nine - Rule of 9

The Rule of Nine is a concept employed by the responder after a certain bidding situation, which is described below. An example should clarify the situational element.

North
East South West

1 2 Pass Pass

?

The question for North, the opener, is whether to reopen the bidding with a double. The situation is that North has opened the auction, the left hand opponent, East, has made an overcall, which is then followed by two passes. There could be two reasons why South passed:

1. South has no values.

2. South has values and wanted to make a Penalty Double, but could not since a double would have been interpreted as meaning the two unbid suits.

In determining the correct reason as to why South passed, the inference made by North is that South has values if North is short in the suit of the opponent, two or less. In the case that North holds three or more cards in the suit of the opponent, then the inference is that South has no values, with which to bid.

Therefore, North should follow the guidelines below when deciding to reopen the auction with a double:

1. Reopen the bidding with a double if the number of cards held in the suit of the opponent is two or less. This guideline holds true even if the holding of North is not up to standard for a Takeout or Reopening Double.

2. Pass, completing the auction, in order to defend based on the inference that holding three cards or more in the suit of the opponent, partner has no values. This is the normal guideline. In the case that North has substantially more values to continue the auction independently, then North should take such action by bidding another unbid suit or employing a cuebid per partnership agreement and allowing partner to make a preference bid. A double, in this instance, should not be employed.

When North decides to reopen the auction with a double, then the partner should take some action. The Rule of Nine assists South in deciding to take the correct action. However, the partner, after a reopening double, should:

1. Bid his/her best suit.

2. Raise the suit of the partner, in this case North, with a minimum of two or more but no less.

3. Pass for penalty when holding length and defensive values in the suit of the opponent.

The Rule of Nine can assist the partner, who has been forced to respond, in arriving at the best action. The concept is explained below:

1. The partner, in this case South, adds:

a. the level of the contract plus

b. the number of cards held in the suit of the opponent and

c. the number of honors held in the suit of the opponent (this includes the 10)

2. If the calculated number is nine or more, then the partner, South, passes for penalty.

3. If the calculated number is eight or less, then the partner, South, should bid.

For example, if South, in the above example, held AQ987, which is the suit of the opponent, then the calculation is:

Level = 2
Number of cards held in the suit of the opponent = 5
Number of honors held in the suit of the opponent = 2
Total = 9
Rule of Nine: South should Pass

Another example, if South, in the above example, held AQ97, which is the suit of the opponent, then the calculation is:

Level = 2
Number of cards held in the suit of the opponent = 4
Number of honors held in the suit of the opponent = 2
Total = 8
Rule of Nine: South should take some competitive action.

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.


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VulkaN...2020

1.	South has no values.
2.	South has values and wanted to make a Penalty Double, but could not since a double would have been interpreted as meaning the two unbid suits.

1.	Reopen the bidding with a double if the number of cards held in the suit of the opponent is two or less. This guideline holds true even if the holding of North is not up to standard for a Takeout or Reopening Double.

2.	Pass, completing the auction, in order to defend based on the inference that holding three cards or more in the suit of the opponent, partner has no values. This is the normal guideline. In the case that North has substantially more values to continue the auction independently, then North should take such action by bidding another unbid suit or employing a cuebid per partnership agreement and allowing partner to make a preference bid. A double, in this instance, should not be employed.

1.	Bid his/her best suit.
2.	Raise the suit of the partner, in this case North, with a minimum of two or more but no less.
3.	Pass for penalty when holding length and defensive values in the suit of the opponent.

a.	the level of the contract plus
b.	the number of cards held in the suit of the opponent and
c.	the number of honors held in the suit of the opponent (this includes the 10)