First priority of the responder is to show if it has a 5 card side suit, if you have a 5/5 you are certain to have a singleton or void in one of the other two suits.
1♥
Pass
2NT
Pass
?
3♣
Splinter in ♣
3♦
Splinter in ♦
3♥
16+HCP No singleton or void and good trumps (3 of top 5)
3♠
Splinter in ♠
3NT
16+HCP No singleton or void and bad trumps
4♣
14+ and 5 good cards in ♣ (3 of top 5)
4♦
14+ and 5 good cards in ♦ (3 of top 5)
4♥
12-15HCP hand no interest in slam
4♠
??
4NT
RKCB
1♠
Pass
2NT
Pass
?
3♣
Splinter in ♣
3♦
Splinter in ♦
3♥
Splinter in ♥
3♠
16+HCP No singleton or void and good trumps (3 of top 5)
3NT
16+HCP No singleton or void and bad trumps
4♣
14+ and 5 good cards in ♣ (3 of top 5)
4♦
14+ and 5 good cards in ♦ (3 of top 5)
4♥
14+ and 5 good cards in ♥ (3 of top 5)
4♠
12-15HCP hand no interest in slam
4NT
RKCB
After an answer different from a sign off (bidding game) responder can proceed to slam cue biding or using RKCB, responder can sign off by bidding game.
This is a sample auction on the follow up's after opener has shown a singleton or a void. After responder has shown a 4 card support, you NEVER play in NT, so the 3NT bid by both the opener and the responder is a waiting bid asking partner to cue bid.
1♠
Pass
2NT
Pass
3♣
Pass
?
3♦
15+ cue bid, no wasted values in ♣ control ♦
3♥
15+ cue bid, no wasted values in ♣ control ♥
3♠
12-14, no wasted values in ♣, ask partner to cue bid
3NT
15+, no wasted values in ♣, ask partner to cue bid
4♠
Wasted values in ♣
4NT
RKCB, imply that having controls in both the unbid suits
You cue bid to show controls of the suit only if you are uncertain if all the unbid suits are controlled, when you discover that all the suits are controlled you can bid RKCB. The failure to bid RKCB implies lack of control of one of the unbid suit.
