Posted 2015-January-04, 03:40
While it is far more popular to show a stop in 2-suited auctions, there is a small advantage to reversing this to asking. Basically we have 4 cases - a stop in 0 1 or 2 suits with the 1 case being for either unbid suit. To cope with this we need 3♥ to handle 2 cases. Playing standard you either have 3NT show no stopper (not ideal) or have no reasonable call on the 0 stopper case. You could, of course, invent a heart stopper, and this is probably what most would do. In that case describing 3♥ as showing a stopper is (arguably) MI though.
With the reversed meanings you can bid 3♥ with 0 stops or a spade stop and use 3♠ to check back for the spade stop. Then 3♠ shows a heart stop and 3NT both - easy.
As for 4♦, obviously denying a stop in the appropriate major. No need for it to be a slam try - we can go with 4♣ or 4M with that - and this caters to the case when Opener was planning to make their own slam try over 3NT (ACB auction). Indeed, if we also play 4♣ as a FJ (so 3♣ is limited) it is possibly impossible for Responder still to hold a slam try, so that information is relevant to the discussion.
(-: Zel :-)
Happy New Year everyone!