Strong Diamond

A site for bridge bidding systems with a strong artificial 1

This site's purpose is to popularise strong diamond systems and compatible conventions because we believe they offer significant advantages over other widely used systems.  

 

However, we aim to be a site of innovation, so even if you don't play a strong diamond you'll be able to pick up some great conventions that fit well with any system.  For instance most of the system's advantages can be incorporated into the Strong 1 variant of the system or Forcing 1 that isn't always strong (See Links for full details).

 
I also intend to add pages to summarize my research.  I currently have a database of around a quarter of a million hands from major bridge competitions on which I can test bidding theories. 

Nigel Jones and Hallam Corbett-Jones England 2012

Jones Diamond System

Nigel Jones & Hallam Corbett-Jones

First Draft 2004 Updated December 2012

This system is level 4 in the English Bridge Union’s Orange Book. It’s also fit in the American Contract Bridge League list of conventions.  Click on the opening bid to see a full description of continuations.

Key

* Artificial

g Game Forcing

f Forcing

RKCB Roman Key Card Blackwood 1430


Bid

Point Range

Length


1♣*

12-15

0

no five card major.

1*f

16+

0

All strong hands are opened one diamond, the only forcing opening bid

1

12-15

5+


1NT

9-11


No five card or singleton major.

2♣

7-11

0

Exactly five card major pre-empts clubs = hearts, diamonds = spades, minimum suit bids to play, 3 of the other minor shows a good raise to three.

2

6-10

6/7

Weak twos

2NT*

7-9


Either six card minor, seven card when vulnerable, minors pass or correct, majors forcing

3♣♦♥

0-6

5/6

Wild style, five card non-vulnerable six card or lower of 55xx vulnerable could be 6HCP in a minor.

3NT

9-13


Solid seven card suit with little else

4♣

0-7

7

Wild style weak seven card suit

4

0-12

7

Wild and random, might be slightly stronger

*I've used the usual Bridge terminology of naming the system after the person who formalised it, so that it can be distinguished from other strong diamond systems. I don't claim credit for all the conventions defined here.

The Jones Diamond System* was largely developed whilst playing a strong club system in England in the 1990s.  Many thanks to William Tunstall-Pedoe for his patience and help in those days playing bridge for Cambridge University and the Cambridge City Bridge Clubs. I was inspired to fully document and formalise the system by playing with my son Hallam Corbett-Jones. 

I intend to update the conventions and convention card as we develop the system, keeping version numbers in case you want to play a specific version.

If you have any other strong diamond systems or compatible conventions please send them to us and we'll include them or add your links.

Most Useful Conventions

For those of you who don't play a strong diamond these are probably the most interesting conventions...

Responses to 1NT - an alternative to Stayman and transfers over 1NT. 

Jones Penalty Traps - the opponents are not allowed to play in any contract un-doubled once we have shown a minimum of 22 HCP.

Our Treatment of Baron 1NT over-call and strong take-out X 15+.  These conventions remove the ambiguity of a take-out double and allow rapid pre-empts.

Wild pre-emptive style playable in strong club and various forcing club systems.

See also Similar Systems for systems that incorporate some or all of the features of the Jones Strong Diamond

Here's the latest and original versions of the strong diamond card...

Strong Diamond Card March 2013.doc Strong Diamond Card March 2013.doc
Size : 79.5 Kb
Type : doc
Strong Diamond Card.docx Strong Diamond Card.docx
Size : 43.401 Kb
Type : docx