Zelandakh, on 2013-August-13, 02:36, said:
With a pick up partner or in the N/B forum, 4NT over a suit bid is always Blackwood
. Thinking about it though, is there a hand for Responder that would bid this way without either heart tolerance or a club fit? 4 spades (since no 2
♦ rebid); 0-1 hearts (no heart fit); 0-3 diamonds (would respond 1
♦); 0-3 clubs (no club fit). 4133 seems to be 2 cards short. Even if we deviated by, for example, treating a weak 5 card spade suit as 4 it is still not possible. In other words, can you come up with a hand that wants to make a natural 4NT bid here?
Kxxxx, void, AKQ10x, Kxx or similar, but very unlikely.
Of course you can't want to bid 4
♠ natural on this auction (particularly if you play SJS), neither can you be void, so if you play kickback, 4
♠ asks aces and 4N is natural but that's not N/B.