The origin of this rule has been lost in bridge history and can not longer be attributed to any one bridge player or bridge author. It evidently developed as a method and was included in partnership agreements as a form of defense. The concept is sometimes referred to as Coded 9s and 10s and also Jack Denies - 10 Implies.

Definition of the Concept

The distinction is that the Rule of 9s and 10s is used generally as a defense against No Trump contracts, not against suit contracts. The partnership agreement, however, can include both applications. The application is also used only on the first lead, and not for any ensuing lead for any later trick.

The concept is that if you lead the 9 spot, then you promise 0 or 2 higher cards. If the lead is a 10 spot, then the lead also promises either 0 or 2 higher cards. Against No Trump contracts, this method of leading can communicate information to your partner.

Q1098

The final contract is No Trump and you are on lead. Applying the Rule of 9s and 10s, you would lead the 9 spot, promising 0 or 2 higher cards.

986

The final contract is No Trump and you are on lead. Applying the Rule of 9s and 10s, you would lead the 9 spot, promising 0 or 2 higher cards.

KJ109

The final contract is No Trump and you are on lead. Applying the Rule of 9s and 10s, you would lead the 10 spot, promising 0 or 2 higher cards.

1096

The final contract is No Trump and you are on lead. Applying the Rule of 9s and 10s, you would lead the 10 spot, promising 0 or 2 higher cards.

If you wish to employ the Rule of 9s and 10s in your partnership agreement, then please, as is customary and mandatory, make this information available to your opponents in the proper manner.

Other Online Description

A more defined, detailed, and descriptive outline of the Coded Nines and Ten (Jack Denies - 10 Implies) can be found at BridgeHands.com. For example, leading the Ace of any suit to the first trick is asking partner to either unblock if holding the Queen of that suit, or inquiring about the count. Although neither a 9 nor a 10 the other leads are equally important for a consistent partnership agreement.

 

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.