I asked my expert panel to discuss redoubles.

When does a redouble say, "I think the Opponent has made a mistake. We’re going to make it. When does a redouble say, "The Opponent thinks we are going down and I agree. Lets find a better spot." 3 - 3NT - Double- Redouble? They made a mistake or run partner run? 2 - 3NT - Double - Redouble? They made a mistake or run partner run? 1NT - Pass - 3NT – Double - Redouble. What is the meaning of redouble? 1 - Pass – 1NT - Pass - 3NT – Double - Redouble. What is the meaning of redouble?

There are some redoubles that everyone plays as SOS, meaning let’s find another strain. Specifically, after a penalty pass of a takeout double. There are other redoubles that are played as strength showing. After a takeout double, a direct redouble shows strength. When there has been agreement about strain, redouble is business. There are other situations that should be played as requesting partner to bid. Suppose partner jumps to 2NT over one-of-a-major showing the minors and RHO doubles. With 2-2 in the minors, you want partner to choose his better minor. With strength in the majors you want partner to sit. Since 2NT doubled might go down two, with three-of-a-minor going down three, you don’t want to play 2NT redoubled. Therefore, redouble of 2NT should ask partner to choose his better minor and pass should suggest playing 2NT-doubled.

What about my six questions about redoubles? As you will see this topic needs work. Some experts play all redoubles show doubt. The following answer makes sense.

Steve Bloom: There is a simple rule to apply here, and it is certainly worth following without overriding partnership agreements: The side with the most information is usually right! 1  - 1NT – Double is not a gamble. The doubler knows that partner has an opening bid, and is well placed to judge the hand potential. Here, a redouble should be to run. Obviously the doubler could be wrong - the opening might be very light, or even a psyche, but preserving the redouble for those rare occasions is a waste of a good bid. The double is based on more information, TRUST IT! The same reasoning suggests that the doubler knows what is going on with your auctions: 3 - 3NT – Double or 2  -- 3NT -- Double. Trust the double, and use a redouble for rescue. Lead directing doubles of 3NT are trickier, and could go either way. Still, the double is a gamble, hoping that the key honors are well placed and that the opposition doesn't have substantial extra values.  Following my principle, redouble should be used to punish the gambler. Finally, what about this auction: 1NT -- Pass – Pass – Double – Pass – Pass – Redouble? If responder had enough to want to play 1NT-redoubled, responder would not have passed on the first round. Thus, without discussion, this redouble ought to be for rescue. 

Marty Bergen: I prefer all as doubt.

If you have a weak hand with a one-suiter, you can bid your suit. With a weak two or three-suiter, you need your partner to help you get to your best spot. If you hold xxxxxxxxxxxxx and it goes 3 - 3NT double, you want partner to bid his best suit. That’s what redouble for rescue is used for.

Kit Woolsey: I play all such redoubles as doubt/rescue. Only, if the logic of the auction indicates that we can't possibly want to play in another strain, are such redoubles for business. In particular: 3 - 3NT – Double - Redouble says that I have a very bad hand. If you sit this one, you better have nine tricks in your hand. 

3 - 3NT – Double – Pass; Pass - Redouble = I have as light a 3NT overcall as could be imagined. This way we almost never run voluntarily - we redouble and give partner one last chance to sit it in case he really thinks we can make it. After 1- Pass -1 - Pass; 1NT – Pass -3NT – Double, Redouble by the 1NT-bidder = xx in spades. With a partial or full stopper, pass. After 1- Pass - 1 Pass; 1NT – Pass - 3NT – Double; Pass – Pass, Redouble by the 3NT-bidder = xxxx in spades. Partner has shown a piece, so if responder has a piece he just passes. This way nobody ever runs unilaterally. If we have 10xxx opposite Jx, they can't bluff us out on AKQ9x.

Grant Baze: 30 years ago at the San Francisco Regional I redoubled three game contracts. Twice they ran and were right and once they sat and beat us a trick. I showed the hands to Bob Hamman and he said: "No sympathy; never redouble for penalties at IMPs." That advice has stood the test of time. The exception is when they double for a specific lead and you redouble because that lead is no problem. A memorable example: North opened 1, South eventually declared 7, East doubled because he was void in spades, South redoubled because he too was void in spades, contract making. In the other room the auction was the same except South did not redouble, North ran to 7NT and was down seven. This auction occurred in an expensive money team game in San Francisco.

That means redouble is to run after 3 - 3NT – Double and 2 - 3NT – Double.

Normally after 1NT- Pass - 3NT, double asks for a specific lead, and redouble would show at least one stopper in that suit. The fourth auction, after 1 - Pass – 1NT - Pass - 3NT, double asks for a spade lead, so responder would redouble with Ax or Kx and a good-ish hand and pass otherwise. Opener would need a two-winner spade suit to redouble. Disregarding the extremely rare exceptions, Hamman is right as usual: Don't redouble game bids for penalties at IMPs.

At IMPs, if you’re sure that you’re you can’t go down more then one trick and there is a reasonable chance that you can make your contract, redouble is the odds bid. If you go down one, you lose an extra 100 non-vulnerable or 200 vulnerable. In 3NT redoubled, making three non-vulnerable is 800, 1000 vulnerable. The redouble gains you 250 points. Redoubled overtricks are 200 non-vulnerable and 400 vulnerable. However, you have to be careful when you redouble. Going down more than one can be expensive. Giving the opponents a chance to pull to a contract that is a good save costs also.

Kerry Sanborn: When a fit has been established or when one hand has shown an independent suit, redouble should be to play. When there can be no long suit to run to, it should be to play. However, when the auction has been jammed, the strengths are undefined, and we have not found a fit, frequently redouble is for runout. Also, when we have shown a two-suited hand such as unusual notrump, a redouble of a penalty double typically shows no preference between the suits, so is technically runout.

3 - 3NT - double- Redouble? Since we were jammed, I would expect the redouble to be two or three-suited and looking for safety. The 3NT bid is often made under extreme duress and can vary greatly in strength, not promising a good chance at making. However, a jump to 3NT is based on playing strength, and here I believe redouble should be to play.

1NT- Pass -3NT- Double. Redouble should express doubt about some suit. It could depend upon the opponent’s agreement as to the double. Generally I would not play redouble as penalty, since there are too many unknown factors, and being wrong could cost more than punishing the opponents for gambling. 1 - 1NT - 3NT - Double. Redouble by responder is to play, showing extras and some help in spades to prevent a run of the suit. If 3NT shows a six-card spade suit, as is popular nowadays, it would be illogical for opener to ever redouble, since he can't know what tricks there are outside of the presumably bad splitting main suit, and he has at most three cards in any other suit.”

When dummy has bid one suit, a double of 3NT tells the opening leader that he has strength in that suit and suggests the lead of that suit. Notice I said suggests.

Bobby Lipsitz: All should be for rescue. Have never had auction 1NT - Pass-3NT – double -- redouble, but think it should show an unstopped major, assuming that's what double is all about.

If double asks for a major-suit lead, redouble by the notrump opener should show very weak majors.

Some experts play most redoubles are for business while some play all redoubles are for business. If you play them all for business or all to run, you can’t have a misunderstanding.

Jill Myers: In a suit game or slam contract, redouble is for business. When we open or overcall and they double for penalty, redouble is for rescue. Business, after all of the problem redoubles.

After a double of Stayman or Jacoby Transfer, redouble is business. After 3 - 3NT – double, holding xxQxxAQ10xxxxx, you would want to redouble for business to prevent partner from running. However, the weak hand is more likely to occur.

Bobby Wolff: I may be showing my age, but all redouble examples are for business. Only in what all high-level players know as SOS redoubles does it ask partner to take it out. A good litmus test would have been (may still be) for a player thinking about your questions, but at the same time frequenting a high stake game around the world, and having these situations arise. Unless there are crazy people involved, all of your examples would be played to "Stay right there partner, you have a pleasant surprise coming down in dummy." Of course, I would make exceptions for people who have discussed this with their partner's and reach specific private agreements, but otherwise it would be unanimous to the extent that all partners playing with a top-level stranger would play these all the same.

Barry Rigal: When 3NT has been doubled for a lead, redouble by both players are for business. All four quoted sequences are to play.

When the auction goes 1NT – Pass- 3NT – Double, some players play the double asks for a specific suit. Others play it asks for the lead of the shortest major. If the double asks for a specific suit, let’s say spades, when you double you don’t have to worry about partner being dealt xxx of both majors or xxx of spades and xx of hearts when you have AKQxxx of spades. You will get a spade lead. Unlucky if you are dealt AKQxxx of hearts. So when the auction does go 1NT – Pass – 3NT – Double, ask the partner of the doubler if the double asks for a specific suit.

David Bird: I would read all these redoubles as strong. The only puzzling one would be a redouble by a player who has opened 1NT. I suppose you could have an understanding that this showed a low doubleton somewhere, but I don't know what responder would be meant to do about it.

Eddie Kantar: Might it not matter if stuff like this comes up at IMPs or matchpoints? After all, at matchpoints, a top is a top without redoubling.
3 - 3NT - Double Redouble say I think they have made a mistake.
2 - 3NT - Double Redouble say I think they have made a mistake.
After 1NT- Pass - 3NT – double, if opener redoubles, I think it means responder needs a stopper in both majors. (I've never seen this redouble before, by the way)   If responder redoubles, I think it means that opener needs both majors stopped (I’ve never seen this one before either). When the double asks for a specific suit, redoubles shows a weak holding 10xxxx or Jxxxx. If opener passes, he is not afraid of the lead.  If responder redoubles knowing opener is not afraid of a spade lead, responder's redouble is for penalty.  Of course I made this all up as I have never discussed most of this with anybody.  

Jeff Rubens: There are at least three possible interpretations: natural, takeout, doubt. It is generally a matter of convention, which redoubles are which; many partnerships never use "doubt." 3 - 3NT - Double- Redouble? To play  2 - 3NT - Double – Redouble is to play 1NT- Pass - 3NT- Double. Redouble is to play  1 - Pass – 1NT - pass - 3NT - Double. Redouble is to play by responder, shows doubt by opener.

Billy Pollack: Good problems, because I think that many partnerships, even highly experienced ones, lack basic understanding including mine!  And it's far more than just SOS vs. gotcha; add to that: "shows doubt".

After 3 - 3NT - Double- Redouble, for business since partner didn't ask my opinion and this shows I have something. Although an agreement that when partner had to bid under pressure, redouble saying help I have nothing, has merit.

After 2 - 3NT - Double – Redouble, even more for business, since partner didn't have to jump. After 1NT- Pass - 3NT - Double, redouble shows doubt: when the double asks for a specific lead. Redoubles show doubt about a specific suit.

After 1 - Pass – 1NT - Pass - 3NT - Double. Redouble says they made a mistake.”

Curtis Cheek: 3 - 3NT - double- Redouble? I think we can make it. I can't remember this ever happening though. 1NT- Pass -3NT- Double. This double asks for weaker major (if not a specific one by agreement). I think redouble by opener shows an unstopped major. Whenever I've run simulations on the effectiveness of doubling with KQJxx of one major and a side Ace anywhere I'm surprised how often the leader is on a complete guess as to which major to lead. 3NT making six is not at all unusual. For this reason I think it is right for responder's redouble to be punitive/speculative, made any time he has a good five-card or longer suit. 1 - Pass- 1NT – Pass- 3NT - Double. Double shows strong spades. Redouble by responder is punitive. I don't see how redouble by opener could ever be punitive so it must be doubt with weak spades. An aside: I'm not sure when it was - maybe the Cavendish a couple of years ago. Partner opened 3 at favorable and Roy Welland, playing with Bjorn, overcalled 3NT. I held AK doubleton in spades and about ten points so I was pretty sure Roy Welland had guessed right. I doubled, "knowing" he was likely cold for four. Of course they ran to a non-making partscore in clubs. 

The most common rescue redouble is when the auction goes three-of-a-suit - 3NT. 3NT is a gamble and often done on a 16-count. Here it makes sense for redouble to mean run to your lowest biddable suit.

Larry Cohen: I don't think there is a "book" answer. All of these require serious partnership discussion. With a new partner, these would all be accidents waiting to happen. My general rules on redoubles: Below game – they are never to play unless specifically defined. Game or higher – to play, with one exception. A 3NT overcall of a three-level bid (in other words, a non-jump 3NT overcall). Over that call, which could be a 16-count flat hand, the redouble (by either player) is S.O.S. All the other redoubles shown in the question would be business by either player.

Karen Allison: For the most part, I think these redoubles show full values for all bidding but doubt in the suit called by the opponents. If there is no suit, 1NT - 3NT – double, I think redouble shows a short, weak suit. 

Zeke Jabbour: I don't believe there are widely accepted standard agreements on these auctions.  Playing with a good player, without discussion, I would be loath to trot out redouble for rescue on any of these auctions. I think the first auction (3-3NT), essayed under the pressure of a preempt is most likely to be the one best served by the availability of redouble for rescue. The second auction does not suggest that partner, who jumped to game, is looking to be rescued.  He may need it, but I don 't know how I could tell. I think redouble should show values. The third auction (1NT- Pass - 3NT-Double) sometimes is alerted as requesting the lead of a specific suit. In that event redouble should suggest doubt that that suit is stopped. Again, the fourth auction probably calls for a spade lead and, by agreement, redouble should have some special meaning, pro or con.

Kathie Wei-Sender: I play any time 3NT is bid directly over a suit and then doubled, redouble show doubt. Over strong auctions, they made a mistake.

David Berkowitz: Typically, by agreement game plus is business. Also specific low-level auctions, defined such as one-of-a-major – pass two-of-the-same-major – double - redouble. All low-level non-defined as penalty auctions, but the "logic of the auction" should apply. 3 - 3NT - double- Redouble? Rescue, since partner can have balanced 16-count. 2 - 3NT - double - Redouble? Business, much different when partner has jumped 1NT- Pass -3NT- Double. All redoubles are business. 1 - Pass – 1NT - pass - 3NT – Double All redoubles are business.

As you can see, this is a complicated issue and could lead to some disastrous results. The simplest answer is to follow Kit Woolsey’s advice. If there is any doubt about strain, play all redoubles of penalty doubles as doubt. The second best way is to follow Steve Bloom’s advice. The side with the most information is right. Redoubles of gambling doubles are penalty. Redoubles of knowledgably doubles are for rescue.