Smolen (over 1N)

After OPENER's balanced 1N opening (15-17), with perhaps
AK K93 KJ54 QJ54
if RESPONDER holds 9+ points, 4 of one major and 5 of the other major, Smolen might be used.
Q754 QT875 9 KQ3

Opener
 Responder
1N 2
2  

Smolen only applies after 'unsuccessful STAYMAN'.
Opener denies a 4 card major with 2.
Responder then shows a game forcing hand and 5-4 shape by bidding the 4 card major at the 3 level.

 

Opener
AK K93 KJ54 QJ54
Responder
Q754 QT875 9 KQ3
1N 2
2 3!
4!  
 


RESPONDER's 3 shows 4 spades and 5 hearts.

OPENER, with 3 hearts, can then bid game in hearts with an 8 card fit.


Opener
AK3 K2 KJ54 QJ54
Responder
Q754 QT875 9 KQ3
1N 2
2 3!
3N!  


If OPENER had fewer hearts, OPENER would rebid 3N.

 

 

Opener
(no 4 card major)
 Responder
Q8765 Q654 9 KQ3
1N 2
2 3!


If RESPONDER had instead had 5 spades and 4 hearts, RESPONDER would bid 3, the 4 card major then, in order to show 5 spades, the other major.


Some call SMOLEN a SMOLEN TRANSFER, since the 1N opener, usually the stronger hand, ends up declarer

Opener
Responder (no Smolen)
Q8765 Q654 9 KQ3
1N 2
2 3

WITHOUT Smolen, you might decide to transfer to the 5 card major and then bid the 4 card major.

 


If you use Smolen, such an auction would show 5 hearts.

Responder's hand must be game forcing.
However, Responder may have a hand strong enough to invite slam!
With this in mind, you might decide OPENER use super-accepts even with Smolen, after the Smolen transfer bid, if, and only if, there is an 8 card major fit:
Opener
AJ3 KJ A654 A54
 Responder (no Smolen)
KQ875 AQ64 9 K43
1N 2
2 3!
4!  

The 4 bid shows 3 spades and a maximum 1N opening.

A direct 4 bid would have shown 3 spades and less than a maximum.