BLACKWOOD
AFTER
INTERFERENCE
Even in bridge, knowing that North and South are attempting slam, there may be a chance for you, as East and West, to enter the bidding. This is rather risky and could prove fatal at times. The individual bridge player must calculate the possible damage and the possible advantage in point score quickly and as closely as possible. If the calculation proves acceptable, then an interfering overcall by East and West of the application of the Blackwood convention by North and South is suitable. This overcall must, however, be based on solid holdings.
However, this page will not discuss the distribution of East-West, which could lead them to make an overcall after North-South has initiated the Blackwood convention, but rather the defense strategy of North-South to the overcall of East-West.
Dealer: North
Vul: None
|
||||||||||||||||||
|
|
|||||||||||||||||
|
North opens the bidding with: 1 
East sees a chance to enter the bidding: 3 
South decides to head straight for the slam in Diamonds: 4 No Trump
West sees a possible 12-card Heart fit and an opportunity to perhaps avoid the possible slam: 5
Analysis:
North could double, and at the end of the play discover that East and West are down
two for a score for North and South of 300 points. Or North could continue bidding
with the hope of making 6 Diamonds for a score of 920 points.
If North decides to double, North must be certain that the prospective double would bring enough penalty points to make it worth while. In the example above, the double would serve no purpose. South would have to assume that the double of his partner is a Penalty Double and would subsequently pass.
If North would like to explore for a slam in Diamonds in the above example, the traditional method was to pass with no Aces, or otherwise bid the cheapest suit possible that contains an Ace, and so on up the line. This traditional method has proven inadequate and bridge players have devised their own conventions of showing Aces. These conventions and/or methods are explained below. They are not complicated or involved with a lot of memorization, but the bridge player should choose one convention for such a situation.
DEPO stands for Double Even-Pass Odd. Using this convention, a double shows zero (an even number), two or four Aces. Pass shows an odd number of Aces, one or three. Using DEPO in the above example, North would bid double, showing an Even Number of Aces. All in all, the DEPO convention saves the partnership more bidding space than perhaps DOPI or PODI. However, DEPO, Double Even-Pass Odd could prove sometimes ambiguous. DOPE stands for Double Odd-Pass Even. It is just the opposite of DEPO as described above. A Double shows an odd number of Aces, and a Pass shows an even number of Aces. Using DOPE in the above example, North would pass, showing an even number of Aces, zero, two or four Aces. DOPI stands for Double Zero-Pass 1. A Double would show zero Aces and Pass shows only one Ace. In the example above, if North has more than one Ace, North would simply bid up the line. This means that North would bid the cheapest suit over 5 Hearts to show Two Aces, therefore North would bid 5 Spades. If North had Three Aces, North would make the next cheapest bid to show Three Aces, and the bid would be 5 No Trump, and so on.Note: Some bridge players have adopted the opinion that the next cheapest bid should be a suit bid. Based upon this Partnership Agreement, North would bid 6 Clubs in the above example.
Some bridge players also use the Roman responses to DOPI. Using this convention, the partner of the Blackwood bidder, North in the above example, would bid as follows to show his Aces:
|
Double: |
shows Zero or Three Aces | |
|
Pass: |
shows One or Four Aces | |
|
Making the next cheapest bid: |
shows Two Aces |
Some bridge players also use the Roman responses to PODI. Using this convention, the partner of the Blackwood bidder, North in the above example, would bid as follows to show his Aces:
|
Double: |
shows Zero or Three Aces | |
|
Pass: |
shows One or Four Aces | |
|
Making the next cheapest bid: |
shows Two Aces |
Note: One important consideration for those bridge players using Key Card Blackwood is the inclusion of the King of Trump. It should be decided beforehand whether or not the King of Trump is included in the responses to all of the above conventions after an interfering call. This decision must become part of the Partnership Agreement.
The individual bridge player should select to choose one of the above conventions. There could prove to be advantages and disadvantages to each and every one of the above conventions. It is true that this certain situation will arise only rarely, but it is better to be prepared. Therefore, it is highly recommended that one convention becomes part of your basic tools of bridge, and that you include this convention in your Partnership Agreement. Also, your decision should be known to your opponents by entering it on your Convention Card.
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.