Ever since Mr. Easley Blackwood created his concept of Ace-Asking for slam attempts, several variations on this theme have been devised, developed and designed. One of those variations is a complex variation devised by Mr. John C. H. Marx, (aka Jack), of London, England, and who was one of the bridge pioneers developing the Acol Bidding System in the United Kingdom. He was born in the year 1907 and died in the year August 29, 1991. Mr. John C. H. Marx won the Gold Cup in the years 1937 and 1947, and once again in the year 1971.

In the year 1938 Mr. John H. C. Marx, together with Miss E. Penguin Corke, H. R. Evans, and S. J. Simon (born Seca Jascha Skidelsky) won First Place in the tournament for the Hubert Phillips Bowl, which is a mixed Teams-of-Four championships of England. The trophy is named after the former English Bridge Union Chairman Mr. Hubert Phillips

Note: Any additional information about John C. H. Marx, aka Jack, including photographs, would be greatly appreciated.

The responder responds to 4 No Trump in a similar style to Roman Blackwood, in that a Key Suit King is shown instead of one of the Aces.

Note: It must be noted that Byzantine Blackwood has no application if there is more than one Key-Card Suit. If there is only one Key-Suit, a King of a Half-Key Suit may be shown, which indicates a genuine suit that has been bid by not supported. A half Key Suit is defined as a genuine suit bid, but not supported. In the instance that both partners have bid a half Key Suit, then the suit bid by the Asker (the No Trump bidder) is the suit, in which a King can be shown.

Note: It also must be noted that Byzantine Blackwood is never initiated on the first round of the Auction. If 4 No Trump is initiated on the first round of the auction, then this becomes and is treated as the Blackwood convention in all its forms.

The complexity of Byzantine Blackwood derives from the fact that there are two different forms of responses and their interpretations. The first form is applied when there is only one Key Suit, and the second form is applied when there are two Key Suits.

Key Suits are:

1.	An agreed upon Trump suit.
2.	Any genuine suit bid and supported by partner.
3.	Any suit bid by partner and responder bids No Trump. For example, if partner bids 1 Spade and responder bids 2 No Trump, then Spades becomes the Key Suit.

According to Mr. John C. H. Marx, if there is only one Key Suit, then the responses to 4 No Trump are as follows:

Responder		Meaning
5		Shows 0 or 3 Aces; or 2 Aces plus the King of the Key Suit.
5		Shows 1 or 4 Aces; or 3 Aces plus the King of the Key Suit.
5		Shows 2 Aces; or Ace and King and Queen of the Key Suit; or Ace and King of the Key Suit plus the King of the half Key Suit.
5		Shows 2 Aces plus the King and Queen of the Key Suit; or 3 Aces plus the King of the half Key Suit.
5 NT		Shows 3 Aces plus the King and Queen of the Key Suit; or 4 Aces plus the King of the Key Suit; or 2 Aces plus the King of the half Key Suit.

According to Mr. John C. H. Marx, if there are two Key Suits, then the responses to 4 No Trump are as follows.

Note: It must be emphasized that Half-Key Suits are ignored if there are two Key Suits.

Responder		Meaning
5		Shows 0 or 3 Aces; or 2 Aces plus the King of the Key Suit.
5		Shows 1 or 4 Aces; or 3 Aces plus the King of the Key Suit.
5		Shows 2 Aces; or Ace and King and Queen of the Key Suit; or 1 Ace plus both Kings of the Key Suits.
5		Shows 2 Aces plus the King and Queen of the Key Suit; or 2 Aces plus both Kings of the Key Suits; or 1 Ace plus the King and Queen of another Key Suit.
5 NT		Shows 3 Aces plus the King and Queen of a Key Suit; or 3 Aces plus both Kings of the Key Suits; or 4 Aces plus the King of a Key Suit; or 2 Aces plus the King of one Key Suit plus the King and Queen of the other Key Suit; or 2 Aces plus the King of one Key Suit plus the King and Queen of the other Key Suit.

Mr. John C. H. Marx authored an article explaining / promoting this concept Byzantine Blackwood, in the Bridge Magazine, in April 1972. Following are two examples for the employment of his conventional method. The meanings of the individual bids are not provided since they correspond to the information described / defined above.

Example 1:

East
	AQ873
	4
	AJ86
	J104
West
	K9
	A832
	74
	AKQ98

West (D)		North		East		South
1		Pass		1		Pass
2		Pass		3		Pass
3		Pass		4		Pass
4		Pass		4 NT		Pass
5 NT		Pass		7		Pass
Pass		Pass

Note: The five keycards shown by the 5 No Trump response by East can only be the King of Spades, the Ace of Hearts, and also the Ace-King-Queen of Clubs. With this information East can securely bid the Grand Slam in Clubs with confidence.

Example 2:

East
	65
	KQ1086
	AK54
	K5
West
	AK7
	A732
	QJ
	AQ106

West (D)		North		East		South
1		Pass		3		Pass
3		Pass		3		Pass
4		Pass		4 NT		Pass
5		Pass		5 NT		Pass
6		Pass		7 NT		Pass
Pass		Pass

Note from author: Following a Byzantine 4 No Trump enquiry, 5 No Trump confirms the joint possession of all the Aces and asks partner to show how many more feature he hold: a King not previously shown or an overlooked key-suit Queen is one feature, and a King-!u33n ranks as two. Once East has located the King-Queen of Hearts, the Ace of Hearts, and the King of Clubs by the 5 Spades response, then he can investigate the Grand Slam by asking for any other features; the one feature shown by the 6 of Diamonds response can only by the King of Diamonds.

Note: end of the article as authored by Mr. John C. H. Marx explaining / promoting his concept Byzantine Blackwood in the Bridge Magazine, which was printed in the United Kingdom in April 1972.

Possible Continuations

After the first response to Byzantine Blackwood, cuebidding may follow. A bid of 5 No Trump after the first response asks for a high card Feature. For example, a King or a King/Queen combination not already shown in the response is counted as one Feature. A second King/Queen combination not already shown in the first response counts as a second Feature. The responses to 5 No Trump are as follows

6 :	Shows 0 or 3 Features
6 :	Shows 1 or 4 Features
6 :	Shows 2 Features

Mr. John C. H. Marx devised a most complex conventional method which has its advantages and disadvantages. The most single disadvantage is that memorization of the guidelines is essential and prior practice with an experienced partner is absolutely necessary.

 

 

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.