Blackwood After Interference

Even in bridge, knowing that North and South are attempting slam, there may be a chance for the players 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.

An illustration should clarify this action in the game of bridge and allow the player to determine on what basis to entertain thoughts of interfering.

Dealer: North
Vul: None

	North A863 A QJ109 AK83
West 9754 QJ742 9652		East J K1098653 62 1074
	South KQ102 AK87543 QJ

North		East		South		West		Meaning
1		3						East makes a preemptive bid on the three level.
				4 NT				South decides to attempt immediately a slam in Diamonds and bids the partnership's Ace-asking conventional method.
						5		West recognizes a possible slam by the opponents and interferes by supporting the suit of partner, which is intended as obstructive and a possible advance sacrifice.

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 conventional method, 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

This conventional method 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:

North		East		South		West		Meaning
1		3		4 NT				Ace-asking bid for Diamonds.
						5		Intended as obstruction and sacrifice.
Double								North doubles to show either zero or three Aces. South must infer that North holds three Aces in order to open the auction. The final contract of 7 Diamonds is bid by South.

Note: A possible sacrifice of 7 Hearts by the opponents could be attempted and the sacrifice is a reasonable sacrifice. However, with experienced players, North and South will realize that a contract of 7 No Trump is also present and even preferable.

 

Alternative Defense Methods With Variable Features

PODI stands for Pass Zero-Double 1

A Pass shows zero Aces and a Double shows 1 Ace. PODI is just the opposite of DOPI in showing zero or one Ace, but otherwise the convention remains the same.

Note: Some partnerships also agreed to use the Roman responses to PODI.

Note: Some partnerships have agreed that the next higher-ranking suit, excluding the established or implied trump suit shows 0 or 3 Keycards, and the second higher-ranking suit, also excluding the established or implied trump suit shows 1 or 4 Keycards. This is based on the conventional response method of Roman Keycard Blackwood.

Note: Some partnerships have agreed that the next higher-ranking suit, excluding the established or implied trump suit shows 1 or 4 Keycards, and the second higher-ranking suit, also excluding the established or implied trump suit shows 0 or 3 Keycards. This is based on the conventional response method of Roman Keycard Blackwood 1430.

 

ROPI - There have been bridge experiences in the past, where the Blackwood convention has been initiated, and the left hand opponent of the Blackwood bidder has doubled. This double could be a Lead-Directing Double. Some bridge players have agreed to use ROPI if this call has been made.

ROPI stands for Redouble shows zero Aces and a Pass shows 1 Ace. Otherwise, the partner of the Blackwood bidder simply answers according to the Blackwood convention with two or more Aces.

Note: Some partnerships have agreed that the next higher bid after the interfering bid, excluding the trump suit, shows 2 Aces; the second higher bid thereafter, excluding the trump suit, shows 3 Aces; and so on.

Note: Some partnerships have agreed that the responses of Redouble shows 0 or 3 Keycards and a Pass shows 1 or 4 Keycards. This agreement is in line with the conventional response method of Roman Keycard Blackwood.

Note: Some partnerships have agreed that the responses be reversed, meaning that the Redouble shows 1 or 4 Keycards and a Pass shows 0 or 3 Keycards. This agreement is in line with the conventional response method of Roman Keycard Blackwood 1430.

 

RIPO is just the opposite of ROPI, and needs no further explanation.

Redouble shows 1 Ace, and Pass shows zerO 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.

Note: A partnership agreement can also include the features as described above for the following suit bids following the interference. These suit responses can be either according to the Roman Keycard Blackwood or Roman Keycard Blackwood 1430 response methods.

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.