I think 7♦ would be a bit overbid(though marginal), you have to rely on ♦2-2, or the defender has 3♦ and length in ♠. If no interference, the auction can be very easy. simple natural bids: S N 1♦ 3NT 4♦ 4♠ 4NT 5♣ 6♦ ====================== But what if West bid 1♥? I think the auction can be: 1♦ (1♥) Pass! - South is very likely to be short in hearts and he will balance. 1♠ 2♥ - If I have 4 spades, I will X previously. So this cuebid can't mislead to spades trump, it's only a strength showing, meaning the first pass isn't no strength, only no obvious bid. 3♦ 3♠ - I can't have spades support, so it's a control showing cuebid. 3NT 4♣ - South don't know North has so much strength, so would bid 3NT. North continue with control showing cuebid 4NT 5♣ 6♦ just as no interference. ====================== When you have no obvious bid, and you think the bidding won't die (in a good chance) if you pass, why not PASS? Of course, this need partner's agreement that PASS didn't absolutely deny strength.