Posted 2012-July-01, 00:49
As I understand it, partner's bids mean the same as what they'd mean after 1♦-1♥;1♠-2♦ playing natural methods. In that auction I don't think 3♥ exists, because it would mean we had to play in 3♥ or 4♦ with a 4351 17-count opposite a 3433 6-count. This means that 2♥ has quite a wide range, but it's low enough for us to be able to sort out the game-versus-partscore decisions.
Opposite MrAce's examples, after 4♦, opener would bid 4♥, responder would bid 5♦ and opener would pass, knowing that we were missing ♣A and ♠K.
I agree there can sometimes be a problem in this type of auction, where we're simultaneously discussing controls and trying to decide whether we have the strength for slam. However, that won't occur on this hand, because responder will always just bid 4♦ followed by 5♦, and it will be clear that he doesn't have anything useful outside the red suits.
Instead of 4♦, we might start with 3♣, which ought to be FSF. That gives us two ways to bid 4♦, and the one via 3♣ is presumably stronger. I'm not suggesting that you should do this in a partnership where "all you discussed was XYZ and not the subsequent bids".
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn