Manchester's annual congress in January was well attended and enjoyed by the participants. There were, over the two days, a number of interesting deals including quite a few slam hands.
On the deal above East was pleasantly surprised to hear partner open with the strongest bid of two clubs. How to proceed?
For partnerships who have a strict requirement of suit quality for a positive response, e.g. two of a major show two of the top three honous and five cards or more, East has to respond two diamonds. West then rebids two notrump to show a blanced 23-24. Among experts the latest method over a two notrump opening or rebid is two under transfers. Here four clubs shows six plus hearts and West must bid four hearts. With a weak hand East passes four hearts, with a strong hand East can now bid Roman Key Card Blackwood. When West shows four key cards (3 aces and the king of trumps) East now checks for Kings, six diamonds showing the other two kings (clubs and spades) and East can now count thirteen tricks.
If the auction started with a response of two hearts, then West should raise to three hearts and now East can proceed to the grand slam by using Roman Key Card Blackwood as above.
Usually it is better if the strong hand asks for controls but here it is better that the weaker hand does, because East knows about the six card heart suit and will be able to count the tricks available.
Using two under transfers responder makes a mild slam try by transferring to the major and then raising to the four level.