Codo, your analysys has a flaw. I understand this position this way: 1. Double - i don't want to play 5M 2. Pass - I'd like to play 5M, but i don't have enough ----> If partner doubles (regressive), i'll pass. If partner bids 5M, i'll pass. 3. 5M - i have a decent offensive hand, with shortage in their suit usually and no extras. 4. Pass - I have a hand with extras and fit and i'd like to be in slam, but i don't have enough cards for pushing into it ---> If partner doubles, i'll bid 5M, if partener bids 5M i'll bid slam Bidding 5M should show around 3 cover cards (♠♥♣-A,K, ♦A,♥Q) along with diamond shortage, and usually a pretty sharp hand (4-5 controls) KQJ10xx Q10x Q QJx - has 1 control and needs partner to hold 6 controls for 5M to make (♠A+♥AK+♣K), so often it won't make, even if we own the board, how it seems. This hand it's between double and pass (1 or 2)