Posted 2010-February-13, 15:47
Partner isn't "making things up," his interpretation is very reasonable, and in my experience it's normal if something would normally be keycard but it's not since it's needed as natural, the next step up is the one that's keycard.
In this auction one might argue that 4D is needed as natural. But opener didn't bid 2D over 2C which he usually would with 4 diamonds. If he happened to choose to bid 2H with his 6-4, he would never bid 3N when partner bids diamonds, even with a double spade stopper that would be horrible. So opener does not have 4 diamonds, and responder does not have 5 diamonds (else 4D over 3N), so there can be no diamond fit. So I would say 4D is keycard, and 4S is just a cue.
However if 4D and 4H were both needed as natural then I think your partner would be consistent with normal kickback rules. With my old partner Kevin we had a stipulation for these situations "if there is only 1 available bid, it is a slam TRY, not keycard."
You have a whole level of bidding over 4C, but if 4D, 4H, and 4N are all natural, then that stipulation would override the "if the next step is needed as natural then the next step up is keycard..." thing.
If 4N was not needed as natural though, then 4S would be keycard and 4N would be a slam try in our rules.
The artist formerly known as jlall