|1 of a suit||Double||??|
When your partner opens the bidding and the opponents make a takeout double, there are many options for responder.
For one, he can pass. This doesn't say he has (or don't have) support. It just shows a weak hand, usually about 0-6 (but it could be more).
Another choice is to redouble. The common meaning of a redouble is 10+ HCP. After this redouble, all further doubles would be for penalty. Some partnerships play the redouble denies support for partner, but I don't feel strongly in this matter.
What about actions other than a pass or redouble? Let's start with a minor-suit opening such as:
What if East bids a suit? Usually, he will have less than 10 HCP (because he could redouble with 10 or more HCP)--but he actually could have more than 10 (sorry if that is confusing). For example, with A K 8 6 5
Q J 8 6
6 5 4
, I would bid 1 over the double. I'd rather start to describe my suits than to redouble and risk the auction getting too high. After I bid 1 to show my spades, I'll do something later to show my strength. If instead I held, say, A Q 7 6
J 10 9 8
10 4 3
, I could redouble and hope to penalize the opponents.
So, when East responds with a suit bid instead of redoubling are his bids forcing? Most players treat 1-level suit bids as forcing. I want to be able to bid 1 with: A K 8 6 5
A J 8 6
6 5 4 and not worry that partner will pass! A 1NT response after a double shows 6-9, balanced. What about bids on the 2-level after a double? Let's looks at these two auctions:
Most agree that 2-level bids after a double are natural and NOT forcing. Since you can redouble with 10 HCP, a 2-level response is assumed to be less than 10 HCP. For example, on the first auction, East could have 4 2
7 6 5
A Q J 9 8 7
and on the second : 7
K Q 10 9 7 6
J 5 4
9 8 6
JUMPSIt has become "standard" to use a jump-raise after a double as weak. So, in this auction:
|1 of a suit||Double||3 of the suit|
The raise is weak (less than 7 points in support). After a major, it shows 4-card support. After a minor, 5-card support. With an actual limit raise (or better), East can bid a conventional (Jordan) 2NT. More on this below.
Be sure to discuss what a jump in a new suit shows. For example:
The most common treatment would be weak, something like: Q J 10 7 6 5
J 3 2
10 9 2..
SUMMARY OF MOST COMMON AGREEMENTS AFTER TAKEOUT DOUBLE:
PASS= WEAK (Usually)
REDOUBLE = 10+ HCP
ONE-LEVEL SUIT BIDS = Natural, Forcing one round (Usually less than 10, but could have more)
TWO-LEVEL SUIT BIDS (not jumps) = Natural, Not Forcing (Less than 10)
Surely, there are other ways to play. Many tournament players use transfers after the double (see my humbling story on this).
Also, most experienced players use 2NT as conventional. The most common meaning is "JORDAN" -- it shows a limit raise or better (this is typically used only after a major-suit opening). So, 1 (Double) 2NT would be bid with: K Q
K Q 3
10 9 8 7 6
J 4 2
. When using this method, a redouble of 1 or 1 surely denies 3-card support (else you'd respond 2NT). There are many other expert treatments available after a takeout double. Jordan is used by an UPH or a PH (passed hand).