Minor Suit Stayman

I recall reading an article about Minor Suit Stayman after 1NT (or 2NT) in the Connecticut Bridge Association's The Kibitzer.  I knew that I liked the scheme but I couldn't remember the details.  Now I've found it: it's by well-known Connecticut expert Harold Feldheim and was published in the February 2007 edition: 4-4 Fit in Any Suit.

The general idea is that 3♠ is a relay to 3NT after which responder describes her hand further: 4♣ and 4♦ show a good suit, while 4♥ and 4♠ are splinter bids showing both minor suits.  4NT is a balanced hand with both minors.  He doesn't say whether the 4-of-a-minor bids should have any particular holding in the suit, or in the other minor suit, but presumably at least a five-card suit with two top honors is about right, and enough of the other minor that it wouldn't be better to start with Stayman or a Jacoby transfer.

In his example, South has ♠64 ♥KT65 ♦AQ96 ♣AK9.  The bidding proceeds 1NT – 3♠ – 3NT – 4NT – 6♦.  Most pairs were in 4NT making five, while some brave souls struggled in 6NT going down one.  But our heroes got to the making slam.  As he says, it doesn't come up often, but when it does, try not to chortle!

There is another way to get to this excellent slam which many pairs would not manage, even though the treatment is, nominally, "standard". Suppose that responder bids 4NT (as many did).  Assuming South decides to accept (not automatic perhaps, but reasonable), then exactly how should South accept?  The answer is that he bids 5 of his lowest ranking four-card suit, in this case diamonds and if North doesn't have diamonds, he bids his lowest ranking four-bagger until they run out of suits in which case they can opt for 6NT (although I suppose there might then be a case for stopping in 5NT).  In this case North, with four diamonds can raise to six right away.