JORDAM 2ST

 This old convention was published by Alan Truscott (1925-2006) in the Bridge World nov/1954, but was re-edit and extended by Robert Francis Jordan (1927-2005) and it is now used by many advance players, so it is known as Truscott Two No Trump or Jordam 2nt and also by Dormer Two No Trump. 

Jordam 2NT was initially made to be use after a major open in 1st or 2st place and after opponent takeout double Responder jumps to 2nt showing a redouble with a flat hand having 4 cards support. 
Opener Opponent Responder 
   1        double   2ST <= Kx Qxxx Qxxx Axx /Jxx Kxxx QJx Kxx

The 2nt do not shows stoppers in all suit, it is just a convencional bid to limit Responder's hand and to destroy opponent communication informing partner that Responder has a 4432 or 4333 hand and 10-11 hcp. This bid is a good description of Responder's hand to Opener. So Opener may sign-off the bidding repeating his suit.

As consequence the jump support to level 3 used before to show a limit hand with 10-11 hcp and 4 cards support has changed it meaning to a more weak hand after agreement by partnership, per example, we can use the jump support after the double to shows 8-9 hcp and with 6-7 hcp we just bid the support at level 2 even with 4 cards.

Many partnership use the jump support with 4 cards after double as 2-5 hcp also a good option because makes more difficult to opponents self organize a interference at level 3 and principally allow Opener takes more precise decision for the final contract.

Thus our recommendation is to use jump support with 8-9 hcp when Vul and to use jump support with 2-5 hcp when nVul, so with 6-7 hcp we bid support at level 2.

In case the bidding goes:
Opener  Opponent Responder
   1        double     redouble <= this denies support of 4+ cards and shows intention in punish opponent at low level up to a possible misfit. So the redouble could be done with singleton, but need 10+ hcp.

After the redouble all low level doubles are penalty, but of course any player that have singleton should not accept a partner's with only 4 cards becaouse opponent will have a 8 cards fit at level 1 or 2.

How Advance should procedure after a weak jump support?           
Opener Overcaller  Responder  Advancer
  1        double         3                ?
   Responder's hand : xx  Kxxx  Jxxxx  Jx  or
                                   Qxxx  Qxxx  x  J10xx or
                                   xx  KJxx  Jxxxx  Qx
Opponents must have a convention that with 8-10 hcp Advance should compete for a partial score in this situation:
Normally with 8-10 hcp and only 4 cards spades Advance should double and with 5 cards Spades Advance should bid 3.
In case Advance has both minors it is more difficult to find a fit at level 4 and a possible overbid may happen.
Of course when the jump support after double was done with 10-11 hcp ignoring the double this difficult is opponent self organize will not exist because Advance will not have 8-10 hcp but could have a distributional hand to compete in level 3 with Spades or at level 4 with a minor.

Playing Jordan the table for Responder's bids after major open are:

Opener Overcaller Responder the meaning of the bidding
1 Pass 2 6-9 hcp with 3 cards support
1 double
 		 2
2
2
2
 1nt		 6-7 hcp with 3 cards support
8-9 hcp transfer to 2 with 3
6-9 hcp transfer to 2 with 6 cards
6-9 hcp transfer to 2 with 6 cards
6-9 hcp transfer to 2 with 6 cards
1 double 2ST 10-11 hcp with 4 cards
1 double 3ST 12-15 hcp balanced with 4
1 double 3
3		 8-9 hcp with 4 cards if Vul
2-5 hcp with 4 cards if nVul
1 double redouble 10+ hcp and denies support
alert for misfit hand and shows
interest in punish opponents
Opener Overcaller Responder the meaning of the bidding
1 pass 2 6-9 hcp with 3 cards
1 double
 		 1
2
2
2
 1nt		 6-9 hcp with 5+ cards
6-7 hcp with 3 cards
8-9 hcp with 3 cards
6-9 hcp with 6 cards
6-9 hcp with 6 cards
1 double 2ST 10-11 hcp with 4 cards
1 double 3ST 12-15 hcp with 4 cards
1 double 3
3		 8-9 hcp with 4 cards if Vul
2-5 hcp with 4 cards if nVul
1 double redouble 10+ hcp and denies support
alert for misfit hand and shows
interest in punish opponents

 

RADICALIZATION OF JORDAN CONVENTION ALSO FOR MINORS
After a minor opening and a takeout double Responder jumps to 2nt to show 5 cards support and 10-11 hcp. The only difference it is the support in 5 cards, because a minor opening could be with 3 cards.

So when the support is weak then Responder bids the jump support at level 3.

Some partnership use a reverse Jordan for minors and they prefer bid the weak support in 2nt and the 10-11 hcp support in the minor at level 3, because then Opener knowing Responder has 10 hcp may try a game in 3nt and so it is recommended that Opener receive the lead bidding nt, not the hand with long minor.
Thus, using the reverse Jordan for minor this is the convention table:
Opener Overcaller Responder
  1         double     3   <= 10-11 hcp with 5+ cards 
                                            xxx KJx Qx K10xxx
  1         double     3   <= 10-11 hcp with 5+ cards
                                              Jx Kx AQ10xx J10xx
  1         double    2ST  <= 5-9 hcp with 5+ cards
                                             xxx Kx Qx J10xxxx         
  1          double   2ST  <= 5-9 hcp with 5+ cards
                                             x Jx Kxxxx 10xxxx  

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