Source: Common Sense Defence Part I
THE purpose is not to introduce more conventions to learn, but rather to show how common sense can solve many of the problems you may be faced with playing in a tournament. Test yourself on the hands below. In each case, you are South, holding the hand shown, and you are playing a simple defence against unusual pre-empts:
1. If the opponents promise length (4+ cards) in the suit bid, double is takeout.
2. If the opponents promise length in some unknown suit(s), double is general values.
3. If the opponents promise length in another, known, suit, double is takeout of that suit.
4. If the opponents are playing a multistyle bid with strong options, assume they have a weak hand until proven otherwise.
5. No-trump bids are (nearly) always natural; jumps are strong
Hand 1: 
A 6 5 
K Q 7 4 
3 2 
A 10 6 4
| West | North | East | South |
| 21 |
Double | Pass2 | ? |
1 Multi, showing a weak two in either major (or possibly some strong option)
2 Shows length in diamonds, suggesting playing there
Answer: 3. You have enough to force to game opposite a double showing general values, but 3NT might be in trouble on a diamond lead. 3 cannot be natural, because if you had a good hand with long diamonds you could simply pass and await developments. Perhaps partner has: Q 2 A J 10 5 Q 5 K Q 9 5 2 3NT has no play on a diamond lead, but 4 is an extremely good contract.
[box] Common Sense Tip 1: If you can (offer to) defend a doubled contract, bidding the suit instead must be strong and artificial. [/box]
Hand 2: A 6 5 K 7 4 A 10 6 4 ® K 6 4
| West | North | East | South |
| 21 |
Double | 22 |
? |
1) A weak hand with diamonds and a major
2) Pass if hearts is your second suit
Answer: Double. As the 2 bid showed diamonds, partner’s double was for take-out. That makes your double of a new suit a penalty double, because partner has implied length in the other three suits. The opponents have no fit and the minority of the high cards: this is the time to punish them for playing such a silly convention. Vulnerable against not, you might consider bidding 3NT instead; but doubling is more fun!
[box]Common Sense Tip 2: When you make a take-out double of one suit you are promising length in the other suits. If either partner then doubles a new suit, that is for penalties.[/box]
Hand 3: A 5 3 2 K 4 2 7 5 4 K 10 3
| West | North | East | South |
| 21 |
Pass | ||
| 22 |
2 |
Pass | ? |
1) Weak two in a major (or possibly some strong option)
2) Pass if your suit is hearts
Answer: 4. It sounds like a cue-bid, but partner’s 3 bid is actually natural.West has not shown hearts, but rather said he wants to play in 2 if South has a weak two in hearts. You have a nice 10 points and threecard support, so raise to 4.
[box]Common Sense Tip 3: After a Multi, suit overcalls are natural if made before you find out which suit opener has.[/box]
Hand 4: K Q 3 5 2 A 10 4 2 K Q 6 5
| West | North | East | South |
| 21 |
2 |
Pass | ? |
1) 8-13 with both majors, might be 4-4
Answer: 4. What can partner’s 2 mean if not length in spades? He could double with general values, or bid a minor suit or 2NT natural. Partner’s 2 is natural. You have an easy 4 bid.
[box]Common Sense Tip 4: If the opponents show a two-suiter, an overcall in one of their suits is natural unless they promise five cards or more in the suit.[/box]
Hand 5: 10 5 3 5 3 2t Q J 6 4 2 Q 4
| West | North | East | South |
| 21 |
Pass | ||
| 22 |
Double | Pass | ? |
1) 3-5 diamonds, 4-5 spades, 0-2 cards in one of the other two suits and 3+ in the other (either way round)
2) To play
Answer: the first thing to do is ask for an explanation of the auction again so that you understand what RHO has shown. The key part of this convention is that there is only one anchor suit (4+ cards), and that is spades (even though opener could be, say, 4-0-3-6, he could also be 5-4-4-0). That means that partner’s double is take-out of spades. Your longest suit is diamonds, so you should bid 3. (Note: if you usually play Lebensohl after partner’s double of a weak two-level opening, you should probably play it here as well – but that’s another level of sophistication).
[box]Common Sense Tip 5: If the opponents are playing something seriously strange, keep asking questions until you understand it.[/box]
If you end up being the declarer on the deal, don’t be afraid to keep asking questions until you get to the bottom of East’s possible shapes, if that is going to affect the way you play the hand. The first time I came up against this weapon I ended up as declarer in 3NT and we had a good few minutes of questions until I really got to the bottom of it.
[box]Common Sense Tip 6: When they bid their ‘anchor’ suit and partner doubles, that is take-out. Treat the subsequent auction as if partner has doubled a weak opening bid in the suit; but when it comes to the play remember what else you know about the opponents’ hands.[/box]