Source: http://www.michaelslawrence.com/
SOUTH : 
9 8 6 5 3 2 
3 
10 8 7 3 
5 2
| West | North | East | South |
| 1 |
Dbl | Rdbl | ? |
This hand shows a bidding trick which is used by all experts. There is no reason that it should be kept a secret.
West opened one diamond, North doubled, and East redoubled. What would you bid if holding the South hand? Should you bid one spade? Or would you worry that bidding showed some points? Perhaps you should pass.
What is your choice, and importantly, what will your partner think you are showing?
VERY USEFUL EXPERT BIDDING TRICK
| K Q 10 4 A J 7 5 A J 10 9 6 |
||
| A J Q 9 8 5 K Q 9 6 4 K 3 |
7 K 10 6 4 2 A J 2 Q 8 7 4 |
|
| 9 8 6 5 3 2 3 10 8 7 3 5 2 |
South jumped to two spades, a bid which normally shows nine to eleven points. As you can see, South is a few points short of that.
Here’s the idea. West and North have opening bids. East has almost an opening bid at the least and may have more. There is no way that South can have the ten points needed for the jump to two spades.
If both North and South are aware that South is broke or close to it, it can be agreed that a jump by South over the redouble shows a weak hand with good playing shape. This allows North to compete if he wishes.
When South bids two spades, the opponents have lost useful bidding room. The auction shown is possible and did occur at some tables where South bid two spades.
At one of those tables where four spades, doubled, was the final contract, declarer faced the following defense.
West led the king of diamonds, East playing the two. West switched to the king of clubs.
Ought South to take this trick?
- YES
- NO
- WHY
You can see, looking at all four hands, that if South wins this trick, West will win the first spade and continue clubs. West gets to ruff the third round with the jack of spades for down one.
South saw the danger and played low. South won the next club and knocked out the ace of spades. East was not able to get in to let West get a club ruff with the jack of spades and four spades doubled came home.
DEFENSIVE ERROR
The defense could have prevailed in a number of ways. An initial club lead would do it. Or if West continued diamonds, forcing dummy to ruff a few times, West would establish a second trump trick.
A BIDDING QUESTION. Your partner opens one diamond and the next player doubles. What should you bid with this hand?
7 K 10 6 4 2 A J 2 Q 8 7 4
This is the hand that East held. Had East bid one heart, East-West would have bid four or five hearts instead of doubling four spades.
East redoubled because he felt he needed to show his good hand. This is a serious error. It is best to play that a new suit at the one level is forcing. If you have a suit you wish to bid at the one level, it is best to do that.
RULE
Save your redoubles for hands where you want to double the opponents or where you don’t feel you can’t be embarrassed by the opponents’ bidding. Here, South jumped to two spades and the East-West bidding never worked out that they had a heart fit.