SUPPORT DOUBLES
For some reason, players using this method either forget to double, forget to alert, or forget that their partner used this convention.
A Support Double can be made only by the Opening Bidder (at his second turn to bid). This will be the 5th action taken in the bidding—after four players have taken a call.
SUPPORT DOUBLESOpener’s Support Double shows 3-card Support for Responder’s suit. For example:
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
1 |
Pass | 1 |
1 |
| Double |
The double says: “Opener has exactly 3 hearts.” Period. It says nothing about strength. It could be a dead-minimum opening, or could be a 20-count. The opener will describe his strength later in the auction. For now, the double shows nothing other than possession of exactly three hearts. If opener had four hearts, he’d raise (to 2 with a minimum, to 3 to invite, or to the 4-level with enough for game). If opener had fewer than three hearts, he’d either pass or make some other call (all of which would deny three hearts).
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Pass | 1 |
1 |
| Double=Exactly 3 hearts |
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Pass | 1 |
1 |
| 2= Exactly 4 hearts |
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Pass | 1 |
1 |
2 = Natural, <3 |
What’s alertable? Nobody can ever be sure what the ACBL alert-rule du jour is; especially when it comes to doubles. I believe that a pair playing Support Doubles should alert all aspects. I would alert every action by opener in the three auctions above. Surely the Support Double is alterable (though ACBL generally advises that doubles are not alertable—go figure!). If the raise promises four-card support, I’d say “ALERT.” If asked, I’d explain that it guarantees four-card support. If opener does something else, such as rebidding a new suit or notrump—or even passing—he has categorically denied 3-card support. Why not let the opponents in on the secret? On the final auction above, I would alert 2 as natural, but denying three hearts. So, I alert every single action by opener. If asked what the ALERT to “Pass” means, I just say: “Denies three hearts.” I can’t see how it can ever be a problem to “over-alert” when you have information which your opponents are entitled to know. Technically, ACBL isn't requiring alerts on most of these actions--but who can keep track?
WHEN ARE SUPPORT DOUBLES ON?After any opening bid and any one-level response, Support Doubles are on (if the partnership has agreed to use this convention). While there might be a few pairs who have “exceptions” (such as not after a 1 response, or not with minimums), I prefer to keep it pure and simple. Any time the auction begins:
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 Any | Pass, X, or bid | 1 of a suit | Any 1-level bid |
| Double |
Double shows exactly three-card support and any strength. Notice that it doesn’t matter what the first Opponent does (he can pass or double or bid), but it is the second opponent who has to bid (even in notrump).
THROUGH WHAT LEVEL?
All of the Support Doubles so far have come on the one-level (even if Opening Bidder’s RHO has bid 1NT). What if the opponents overcall on the two-level? I suggest you use Support Doubles as long as the bidding is not above 2-of-responder’s suit. So, if it goes:
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Pass | 1 |
2 |
| Double |
Support Doubles are on. Even on the two-level, they can be made with a minimum (though, if you’d like to eschew a Support Double on the two-level with a really awful-looking minimum, your partnership can agree to do so). If they overcall above two-of-responder’s suit, Support Doubles can still be on, but they show extras. For example, after:
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Pass | 1 |
3 |
| Double |
Opener can double to show three spades, but it is not mandatory. Such a double would announce extra values (more than a weak notrump type of hand). If your partnership prefers to use double as something else (such as “extras—but not promising 3-card support”), that’s an acceptable alternative agreement. Just make sure you agree and write on your convention card through what level you play Support Doubles.
SUPPORT REDOUBLES
What if instead of overcalling (after the response), the opponents make a Takeout Double. For example::
| OPENER | OPPONENT | RESPONDER | OPPONENT |
|---|---|---|---|
| 1 |
Any | 1 |
Double |
| ?? |
You can’t make a Support Double (bridge doesn’t allow doubles of doubles—though at times, I’ve thought it would be a great idea). But you are allowed to Redouble, and for that reason, pairs who use Support Doubles also use Support Redoubles. In the auction shown, Opener’s Redouble would announce 3-card spade support and say nothing about strength. Just as with Support Doubles, Support Redoubles (and the negative inferences) should be alerted.
Support Redoubles can occur only on the one-level. After a two-level response, Support Doubles or Redoubles are never used. For example, if the auction begins by your side 1 P 2, and the opponents now overcall (or double), a double (or redouble) would be for business (not showing three-card club support).
Warning: In all my years of teaching experience, I’ve never seen a convention that causes more brain-freeze and confusion than Support Doubles. Players constantly forget to use them, forget to alert them, forget to realize partner has used them and forget the negative inferences. I recommend this convention only for players with strong concentration abilities who play frequently.
If you would like to learn more about Doubles, you'll find them in Larry's book: 
Larry covers many topics on his cruises, including Doubles. For more information: 
To play 4 practice deals:
1 Throwing an honor
2 12 fast ones
3 Defense again
4 A Careless Overtrick