Scoring: MP
I opened the following hand 2NT (20-21 bal) and the following auction occurred:
2NT - (P) - 3♣ (1) - (X)
3♠(2) - (X) - P - (P)
3NT - (P) - 4♦ - (P)
?
(1) 4 card puppet stayman
(2) No 4 card major, but has 5 diamonds
We have agreed to open all hands with a 5 card major in another way. I believed my partner's 4♦ was a slam try and asking for keycards. He believed he was "getting out" into 4♦. I believed if that were the case then he should just have passed 2NT (which would have been down 2). He claimed that against decent pairs, they would always double 2NT and that we should have a runout. I can see this reasoning over 1NT, but does anyone play this over 2NT? Is this a legitimate concern? By the way, the cheapest we could make a runout is at the 4-level.