You and partner have reached a point in the bidding where you
determine there is a slam.
There are two reasons for this convention:
1. You are playing imps and you are missing the trump jack, while you have a bit extra on
the side and, therefore, 6NT might be a safer contract.
2. You are playing matchpoints and since 6NT scores more than six of a suit, you are
interested in reaching 6NT if 12 tricks are there without the need of a ruff.
The 6NT Try is the "suit below the trump suit at the six level."
Example:
| opener | responder |
|
♠ A x x x ♥ A J ♦ K Q J x ♣ Q 10 x |
♠ K 10 x x ♥ K 10 x x ♦ A x ♣ A K x |
| 1NT | 2♣ |
| 2 ♠ | 3 ♥(*) |
| 3 ♠ | 4 NT |
| 5 ♥ | 6 ♥ |
| 6 NT | - |
*-slam try in spades
After a 15-17 notrump, responder uses Stayman, locates the spade fit, and checks for aces. Assume that Responder's 4NT is Keycard Blackwood. Over 5♥, he knows that the queen of spades is missing. He also knows the partnership has at least 32 HCP. So he bids 6♥ "6NT Try" and opener, with extra values, chooses to play in 6NT.
Suppose opener held:
♠ A J x x
♥ A x
♦ K Q x x
♣ Q 10 x
He would choose to play 6♠, especially since he holds the jack of spades.