Responses to 1NT Stayman, Jacoby and Smolen

In previous editions of ESRA MAGAZINE, we have explored bidding methods after an opening suit bid. In recent teaching sessions, I have found it necessary to return to basics in hands opened with 1NT indicating a flat (4-3-3-3 or 4-4-3-2) or semi-flat (5-3-3-2) distribution and, typically in the Standard American and Israeli systems, 15-17 HCP.
The Stayman convention, primarily used to find a 4-4 trump fit in a major suit after the 1NT opening bid, remains one of the oldest and most popular conventions of modern Contract Bridge. While named after Samuel Stayman who popularized and first wrote about it in 1945, it was actually invented in 1939 by the British player J.C.H. Marx, who published it only in 1946.
The main reason for seeking a fit in a major suit is that the success rate for 4♥ or 4♠ with a partnership holding of 26 HCP is about 80%, whereas 3NT with 26 HCP has a success rate of only 60% and 50% with 25 HCP.
The 2§ Stayman response to a 1NT opening bid, indicating that responder has one or both 4-card major suits is well known to the vast majority of readers so I will not elaborate further except to advise players to keep subsequent bidding simple:  With no 4-card major, the NT opener should always respond 2¨, bid the major at the 2 level with only one of them, and 2♥ with both.  Even with a well-established partnership, avoid other bids like 2NT indicating a maximum 1NT or both majors.
Most modern bidding systems, including the standard ones, use Jacoby transfer bids by responder in conjunction with Stayman over 1NT openings. The familiar 2¨ and 2♥ bids by responder indicate a holding of 5 or more cards in hearts and spades, respectively, and require the NT opener to make the transfer bid of 2♥ or 2♠ as appropriate.  This allows the partnership to stop at the two level in the indicated major when responder has a weak hand and explore game and slam possibilities when responder has upwards of 8 points.  The considerable advantage of playing transfers is that, in all cases, the final contract is declared by the NT opener and the opening lead is thus into, rather than through, the strong hand which remains closed.
What about the case where responder has a five-card major and four or five cards in the other major as well?
With weak hands, less than 8 HCP or equivalent, transfer to the 5 card major and pass opener's subsequent bid.  Don’t worry if sometimes the partnership ends up playing in a 5-2 fit rather than the 4-3 or 4-4 fit in the other major. It’s a small price to pay for the advantages of leaving other methods for getting to the correct game and slam contracts.
With invitational hands (8-9 points), game-going hands (10-14 points) or slam-going hands (15+ points), use Stayman.  If the opener bids a major, raise that major to invite to game, jump to game, or bid another suit to show slam interest, as appropriate.
The case where the NT opener bids 2¨ to indicate no 4-card major, requires closer consideration.  A 4¨ bid by responder now shows 5 cards in both majors, allowing the strong hand to choose the better fit. Responder passes or continues the bidding over the game level to explore for slam.  With 5-4 and an invitational hand, responder simply bids 2♥ or 2 ♠ showing 5 cards in the bid major and 4 cards in the other, but remember, opener can pass with a minimum.  So what do you do with game or slam going hands?  A jump to the 3 level in one’s 5-card suit is forcing and gives declarer the choice of game in NT or 4 of the bid major. (Sometimes the NT opener may even prefer to play in the 4-3 Moysian fit.) This, however, can lead to contract being declared from the wrong hand as in the following case:

  North
♠ Q 8 2
♥ A 9 3 
¨K 5 4
§A K 1 0 7

  South
♠A K 6 5 3
♥ K 8 7 4
¨ 8 7 3
§ 4

North opened 1NT, bid 2¨ over South’s Stayman enquiry and 4♠ over South’s subsequent 3♠ jump.  I wouldn’t argue with a 3NT bid from North with such a flat hand but I generally prefer suit contracts with such rich holdings in Aces and Kings. As it turned out, West had the natural lead of Q¨ from Q J 10 against 4♠ played by South, putting paid to the contract since South still had to lose three diamond tricks and a heart.  Played by North, there are several possibilities of bringing home 4♠.
For established partnerships, I suggest using the Smolen convention. Over 2¨, responder jumps to the 3 level in the 4-card major, indicating 5 cards in the other. So, in the above hand, South would bid 3♥, indicating 4 hearts and 5 spades. North now bids 4♠ and the contract is played from the correct hand.
Pretty simple but easy to forget, so be careful.  Remind partner that you are playing Smolen – good advice regarding all unusual partnership conventions.