Six-five, Come Alive!

Dave Neuman, my other partner besides Jenn, picked up this one yesterday:

♠ 109876
♥  none
♦  AKJ752
♣  A4

Nice hand, just 5 losers, could be really good if partner has spades, questionable otherwise.  Dave opened 1 Diamond, and heard LHO bid 1 Heart and partner make a negative double.  Just what he wanted to hear!  Partner has 4 spades and LHO's strength is in his void!  Better still, RHO raised to 2 hearts.   Slam is now a good possibility, since partner figures to cover most of your losers.  How should you proceed?  Should you take control of the auction or get partner involved?

Dave and I have an agreement that when one of us makes a negative double of a major suit overcall, we promise at least 4 of the other major.  After a 1 Heart overcall, a double shows 4 spades; after a 1 Spade overcall, a double shows at least 4 hearts.  We therefore also have the agreement that subsequent bidding by opener is as if the suit shown by the negative double was bid naturally.  So after the auction 1D-1H-Double, opener's bids are the same as if the auction was 1D-Pass-1S.  This is something that is worth discussing with your regular partner. 

If you want to take control, you could just bid 4NT, which partner would interpret as RKC for spades, the suit bid by partner (by inference, his negative double was a spade bid).  This commits the hand to the 5-level, which might be too high if partner has, say, QJxxx/Kxx/xxx/Qx.  But it has the advantage of pinpointing the trump honors to see if they are good enough for slam. 

If you want to get partner involved, you have two good options:   4 Diamonds, which shows a spade fit and a really good diamond suit, or 4 Hearts, which shows a big spade fit and heart shortness.

Dave decided to bid 4 Hearts.  Now the auction took an unusual turn.  LHO doubled, and partner redoubled!  What is going on here?  Dave and I have a general agreement that when a cue bid is doubled, a redouble shows first round control.  In this context, it also indicated slam interest.

So now Dave knew that I had the ace of Hearts and interest in slam.  So he knew he had a place to put his club loser if he got a club lead and could reach my hand to discard his club on my ace.  But he didn't know whether my slam interest was based on my trump holding. If I had, say, the queen of diamonds, that alone would be enough to be interested.  Now he had the options of bidding 4NT, RKC, taking control, or 5 Spades, asking me to go on to slam if I had a decent trump holding.   He chose to let me decide by  bidding 5 Spades.

I held:

♠ AJxx
♥  Axx
♦   xx
♣  Jxxx


I looked at my AJxx of spades and decided that this should be good enough trump support, so I bid 6 Spades. 
 
The two hands together are:

♠ AJxx
♥  Axx
♦   xx
♣  Jxxx

♠ 109876
♥  none
♦  AKJ752
♣  A4

We got a heart lead, but would have been in good shape even with a club lead.  The slam needs either 2-2 spades and no worse than 4-1 diamonds, or 3-1 spades with honors split and 3-2 diamonds.  This feels like a pretty good overall shot to me (if any of you are so inclined, you can calculate the exact odds), and indeed it came home when LHO had the stiff king of spades and diamonds split 3-2.