Slam Potential with a Void
Playing in a Swiss Teams, you pick up the following exciting hand: 
— 
A 5 4 3 
A K Q 9 8 6 5 4 
5.
With neither vulnerable, your partner opens 1 and RHO passes. You are interested in only three specific cards in partner’s hand. What is your plan for getting this information?
To kick things off, let us suppose that you had exclusion Blackwood available. Your partnership has, in a general way, agreed to play this. My preliminary poll of players shows that the agreed step responses vary widely. Do you have an agreement with your partner? How does the queen ask work?
Over exclusion (here it would be a forcing heart raise, followed by a jump to 4S), I’d respond just as I would to 4NT key card: 1st step = 0/3 (or 1/4 if playing 1430), etc. Over a response that says nothing about the trump queen, the next step asks for the queen and the step after than (skipping one open step) asks for specific kings. In short, I play exactly the same step responses over exclusion as I play over key card (although, obviously, in some sequences you run out of steps sooner after some exclusion bids).
January 27, 2007 Joe Stokes
I would like to offer 1 consideration for Joe. Often, on your sequence, 4 Spades will be the final contract. Exclusion B/W has to be treated gently. If there is a way to mis-interpret it, be assured that partner will do so with alacrity. Try 5 Spades and there is no confusion. If he shows 1 just play 6 hearts, if 2 play 7. If not knowing about the queen is troublesome to you, Start with Jacoby 2 NT, and cue bid. After pard cues Spades at any point, but especially if he does NOT, just use old Black to get what you need.
February 1, 2007 george jacobs
I bid 4S which is exclusion key card blackwood. Steps are 0, 1, 2…
Queen ask is the next step.
February 4, 2007 Mohan