I sent short answer so now I'll try to explain why I would bid this way. Looking at our hand we will be at least in 6 and want to find Grand. The problem is to choose perfect trumps. I'm sure that cue 4♠ is the road to nowhere. Look at the most detailed Fred's answer: Agree. For the only reason: when partner will jump to 6♣? Having no side controls? Well I see only one hand when he might jump: ♠Axx ♥x ♦QJx ♣AKxxxx. And it gives us cold 7♣. But with all other hands (at least without ♠A) he'll bid only 5♣!. What else he may bid with these soft values ♠Qxx ♥Jx ♦Qxx ♣AKxxx?? Agree. It will never happen. Look at the above hand. Will he bid 7? Never 'cause 6♥ jump over 5♣ isn't invitation to 7. Just responder relies on opening of 1♣ and opener has nothing above it. Also opener will take into consideration why partner has chosen this sequense and not another one (5♠ over 5♣ and next 6♥ will really invite 7). So what's the main idea of this hand? Not mess around with nebuluos cue 4♠ and other slammish bids when you have DIRECT DESCRIPTIVE sequense! We DON'T need cooperation with partner!! We must force him to make the only final decision - to choose trumps!!! Thus first bid - 5♠, voidwood (we play with an expert partner, not with the random palooka from the local club). If partner shows 1 KC we bid 6♥ as the final contract. If he show 2 ... No, I cant agree with Fred's words: Why to guess if we have partner for that? 6♠! How else good (!) partner can take it? Only as: "Partner, I have AKQxxx as side suit, semi-fit in clubs (Hxx or Hxxx - don't forget that 1♣ is only 3+) and all controls. Look at your hand and bid 7♣ or 7 in my suit (or 7♦ if you're not sure what's my suit)". Of course we don't have jack in our suit (wouldn't ask partner to choose - wd just bid our suit). Of course suit is headed with AKQ (grand isn't a gambling, and opener doesn't guarantee high honor in this suit). And partner will prefer 7♥ with ♠Hxxx ♥J ♦Qxx ♣AKxxx as a guard against bad breaks! Is it so tough reasoning? Don't think so. And final comment. I don't take this sort of rconsideration: Well, my partner isn't Mrs.Guggenheim so I'm not gonna be Unlucky Expert. Also - no pain, no gain. And finally - if hold on this philosophy you may forget about good but delicate slams. Dinos1.