This is a neat gadget to solve an uncomfortable problem.
The bidding:
Partner Opp. You Opp.
1♦ Pass 1♠ 2♥
Pass Pass ?
Your hand:
♠ A J 9 6 3 ♥ 4 2 ♦ Q 8 ♣ K 8 4 2
What a dilemma! Your choice of a rebid are all bad:
1. Rebid your mediocre 5-card spade suit (only perverts repeat 5-card suits!)
2. Bid 3♣, an anemic 4-card minor suit
3. Bid 2 NT with no heart stopper
But if you and partner play "card showing doubles", you would double in this sequence, showing a decent hand (10+ points) with no convenient bid. Partner will know it is a takeout double, not a penalty double.
© 2013 Roberta Salob