These notes are reproduced with the permission of Dave Huggett who gave the seminar on the subject on October 6th, 2019.
They have been modified to make them interactive. Where you see a '?' in a dropdown box, select a bid. If you make an incorrect bid three times you will be able to see the correct bid.

Forcing or Non-Forcing

One of the hardest concepts to grasp is that of the forcing bid, that is to say when a bid is made by either one of the partnership which absolutely demands that the bidding does not die. A forcing bid can fall into one of two categories: -

1)    The bid is forcing, but the subsequent auction can stop short of game. We call this ‘forcing for one round’.

2)    The bid is not only forcing, but the subsequent auction cannot stop until game has been reached.

Forcing Bids

After an opening bid of one in a suit a change of suit by responder is forcing.

This is absolutely fundamental and the reason is not too difficult to understand. Because an opening bid of 1S/1H/1D/1C usually falls in the range 11-19 points it is necessary to respond to such a bid with a minimum of six points in case there are enough points between the two hands for a game call. However as well as having just six points the responder might have a lot more, twelve say or fifteen or indeed any number, and in this instance the responder would know that there were enough points for a game call. However unless his response was forcing he would be compelled to bid what he might imagine to be the most likely game in just one bid. Clearly this is nonsense, which leads to the obvious conclusion that a change of suit is forcing.

A change of suit is not necessarily game forcing however. Take the following example: -

W S 87 H AKT872 D A76 C Q7 E S AQ63 H 53 D K832 C T63 W 1H 2H E 1S End

2H should prove likely to make but while it was necessary for East to respond in case his partner had a much stronger hand, the rebid of 2H should dampen his enthusiasm.

But sometimes the responder will make sure that game is reached even if his partner does not have anything more than a minimum hand in terms of high cards. : -

W S 87 H AKT872 D A76 C Q7 E S AQ63 H 3 D K832 C KJ92 W 1H 2H End E 1S 3NT

East knew from the start that he was going to end up in game but he had no idea after hearing just one bid from his partner what that contract was going to be. It might be anything from 3NT to 7C! But after his partner’s rebid, which not only shows a minimum type hand but also a one-suiter, East knows that there is no hope of a slam or indeed of play in a suit so he makes the practical bid of 3NT. Imagine how annoyed he would be if the opener passed his 1S bid.

Non-Forcing Bids

When the opener has started with 1NT things are different and that is because the hand has been described very clearly in just one go. As we are aware the hand will be balanced within the range 12-14 points – or whatever your system dictates - and will contain just one doubleton at most. As a consequence the responder is in a much better position to be able to gauge the final contract in just one go. Accordingly suit bids of 2S/2H/2D are not forcing if transfer bidding is not used and are called ‘weakness take-outs’. 2C is of course Stayman. To set up a forcing sequence (again without the use of transfers) the responder has to bid at the three-level.

Immediate bids in support of opener’s suit are also not forcing but the higher the bid made the fewer the Losing Trick Count tally will be. So 1S – 2S is not forcing, with the responder showing a LTC of 9, and 1S – 3S is not forcing with the responder showing a LTC of 8.  The same applies if one suit is supported in the middle of the auction, so that 1H – 1S – 2S would not be forcing, with the opener showing a LTC of 7. Similarly 1H – 1S – 3S is also not forcing with the opener showing a good hand with a LTC of 6.

Game-Forcing Bids

There are a number of occasions when a bid made is not only forcing, but game-forcing too. This means that the auction cannot die until game has been reached. It does not mean, however, that game has to be reached as quickly as possible! If a bid made at the three-level, say, is game-forcing, then it leaves lots of space for the auction to explore better things – maybe a slam. There are lots of situations where a bid is game-forcing, far too many to enumerate here, so we will simply look at the most common situations:-

1)    A jump bid in a new suit by responder is game-forcing. 1D – 2S for example means that the auction cannot die before some game has been reached.

2)    Similarly a jump rebid by opener in a new suit is game-forcing. So the sequence that starts 1H – 1S – 3D cannot finish until game has been reached.

3)    A jump rebid by opener in his own suit after a two-level response in a new suit is also game-forcing, but a jump rebid after a response in a new suit at the one-level is encouraging but not forcing, (although game might well be reached.)
So 1S – 2D – 3S is game-forcing, but 1H – 1S – 3H is encouraging but not forcing.

4)    After a 2C opening the auction has to reach game unless the opener rebids 2NT to show 23/24 points, after a 2D denial. All other sequences are forcing to game.

5)    After partner has responded in a new suit at the two-level, a reverse by opener is game forcing. So the sequence 1H – 2D – 2S is game-forcing. To see why that might be useful just look at the following hand:-

W S AT85 H AK876 D K5 C K7 E S K92 H 9 D AQJT87 C A53 W 1H 2S ?? E 2D 3D

How the bidding continues after this point need not concern us here, although West has a clear-cut raise to 4D to begin with. Suffice it to say that 7D is the correct contract and can be made by ruffing a low club in dummy. After West has reversed, the 3D bid becomes game-forcing leaving lots of room for exploration.

Another situation where it pays to have a bid as game forcing is after opener has rebid 2NT after a two-level response from partner. In other words the 2NT bid is taken to be 15-19 instead of the more orthodox 15-16. Why this is important can be seen from the following example: -

W S AJ5 H KQT95 D J8 C AKJ E S K73 H AJ2 D 93 C QT986 W 1H 2NT (game forcing) 4H E 2C 3H End

Without this understanding West would rebid 3NT and East would have to pass, unaware of his partner’s five card heart suit. Playing the prescribed methods West could now rebid 2NT, game forcing, which enables responder to bid 3H, showing three-card support and offering alternative games.

A convention known to most people is Fourth Suit Forcing but it is often applied without due thought and whether any continuations after the fourth suit are forcing or not. Let us look at a couple of examples: -

W S 5 H AQ865 D QT9 C KQ76 E S KQ865 H J3 D 854 C AJ2 W 1H 2C 2NT E 1S 2D (Fourth Suit Force) End

Here responder has enough to invite game but with a minimum hand and a potential stop in diamonds opener bids 2NT, which is not forcing. The corollary to that of course is that if opener is stronger than might be expected he should make more than a minimum bid. So if in the above hand opener held K Q 10 of diamonds, say, he should bid 3NT at his third go.

However if the fourth suit is bid at the three level it is sensible to play that as game forcing.

W S 6 H A9865 D KQ76 C QJ4 E S AK875 H K2 D AJ2 C T65 W 1H 2D 3NT E 1S 3C (Fourth Suit Force) End

In this example responder knows that his side has the values for game but that game could be 4S, 4H, 5D, 3NT…. A bid of the fourth suit clarifies the matter but in any event 3C here is unconditionally game forcing.

Generally speaking unless any bid has been used artificially as a game-forcing tool then any no-trump bid is NOT forcing while immediate or delayed support of partner’s suit merely shows strength appropriate to the bid and is not forcing either. (This is certainly true when supporting a major. There are cases when jump support for a minor is forcing. Sorry!)

Doubles - Summary

1. Take-out or Informatory double.
 A double of a suit bid shows a hand short in the bid suit but with support for the other three. Typically it asks partner to bid his best suit at the right level. If there is a response by the partner of the opener then the responder to the doubler is not obliged to bid but otherwise he is, unless he wishes to convert the take-out double into a penalty double.

2. Negative or ‘Sputnik’ double.
After partner’s opening bid has been overcalled, a double by the responder to opener is for take-out. Typically after 1C/1D – (1S) – Dble shows four hearts and any number of points from 6 up OR five hearts and less than nine points. A 2H response shows at least five hearts and at least nine points. After 1C/1D – (1H)– Dble shows precisely four spades while a bid of 1S shows 5+ spades. After 1C – (1D) – Dble shows four spades and four hearts.

3. Responsive double.
If partner doubles a major which is raised by the next hand then a double by the responder of the first doubler shows the minors.
E.g. 1H – Dble – 2H – Dble shows the minors.

4. Competitive double.
If partner overcalls a suit which is raised by the partner of the opener then double by the partner of the overcaller shows the other two suits but with tolerance – usually a doubleton – of the overcalled suit.
E.g. 1H – 1S – 2H – Dble shows the minors but with spade tolerance – usually two card support only.

5. Lightner double.
The double of a freely bid slam by the player not on lead asks for an unusual lead to alert partner to the fact that only a precise defence will defeat the contract. Similarly the double of a freely bid no-trump game suggests a solid suit which the opening leader has to find. Where dummy has bid a suit it is usually that suit which has to be led.

6. Penalty double.
Usually made at a high level as nearly all low-level doubles are of the kind mentioned above. The exception is that a double of a 1NT opening or a 1NT overcall are strictly for penalties and the responder to such a double will only take out with a very weak hand and at least a five card suit.

Generally speaking all low-level doubles are for take-out but because of this there are some important considerations to be aware of. Suppose you hold: -    

W S AQT76 H 3 D KJ75 C KT6

You open 1S and the next hand overcalls 2H, which is passed, back to you. What, if any, action do you take now?

By far the worst you can do is bid 2S – ‘I had a five-card suit partner’ – but coming a close second is to pass! Where have all the points gone? You have a minimum hand and yet the opposition have made no forward going move, leaving to the inevitable conclusion that partner must have some values and yet has declined to bid. Given the propensity these days to compete on tram tickets we can only surmise that partner would have liked to have made a penalty double but is unable to because it would be for take-out! So you double instead, delighted if partner can pass but happy also if he bids one of our suits. Let us imagine the complete deal is: -

N S J2 H QT974 D Q4 C A932 W S K5 H AKJ852 D T82 C Q4 E S 9843 H 6 D A963 C J875 S S AQT76 H 3 D KJ75 C KT6 W2H

Playing in 2H* declarer figures to lose one spade, three or four hearts, two diamonds and two clubs – a three or four trick defeat saving against a part score and yet nobody has really done anything wrong.

It is also advisable to have the arrangement that after your 1NT opening has been overcalled then a double by partner is still for take-out. (Of course you can play the double there for penalties if that is your arrangement but statistics seem to suggest that playing it for take-out is more useful.)

Look at the following hand: -

N S A765 H 86 D K652 C QJ8 W S Q93 H KQJT72 D A4 C 93 E S JT H 43 D 9873 C AT642 S S K842 H A95 D QJT C K75 S 1NT 2S W 2H End N Dbl E No S2S

Here 2H is an easy make for E/W but N/S can make nine tricks in spades and they would never reach that contract unless responder doubled the 2H bid.    

So when else is a low-level double for penalties?     Certainly when opener has made a weak bid such as a preempt and the next hand has overcalled. It makes no sense to ask partner to choose a suit he cannot have so a double in that case would be for business.   
e.g. 3D – 3H – Dble            Here Dble is strictly for penalties.

Lastly, everyone knows that a double of 1NT is for penalties, but do you know what is meant when your partner doubles a weakness take-out, or as would happen more often these days, a transfer? Or Stayman? Our advice would be that to double a weakness take-out is also for take-out in an attempt to compete in the auction while a double of a transfer or Stayman shows a strong hand and one that would have doubled 1NT. Remember that in both the above cases you have another chance to bid because opener has to respond to a transfer bid and also to Stayman. Look at the following example: -

N S KJ76 H J84 D QT75 C J9 W S QT2 H A65 D A98 C K754 E S 93 H KQ972 D 642 C Q83 S S A854 H T3 D KJ3 C AT62 W 1NT 2H No N No No 2S E 2D No No S No Dbl End N2S

Initially East might have a strong hand but once he passes the transferred bid he is known to be weak and so South can enter the bidding with a take-out double. 2H might or might not make but 2S certainly will!

Practice Hands

Hand 1

N S 75 H KQT8 D 8642 C AJ7 W S Q63 H AJ9753 D A9 C Q6 E S KJT H 42 D 753 C T8543 S S A9842 H 6 D KQJT C K92 S 1S Dbl W 2H No N No No E No End S1S*

North cannot double at his first go as that would be for take-out. Opener has to reopen with a double, ostensibly for take-out but which is converted into penalties.

Hand 2

N S QJ6 H A75 D J8 C QJT75 W S K73 H 92 D AT975 C 962 E S T852 H J64 D K632 C 84 S S A94 H KQT83 D Q4 C AK3 S 1H 2NT 4H W No No No N 2C 3H No E No No End S4H

2NT is game-forcing, 15-19, allowing responder to look for the heart game.

Hand 3

N S AQJ986 H KJ7 D KQ8 C Q W S T73 H T86 D A62 C AJ95 E S 42 H 543 D T97 C T8642 S S K5 H AQ92 D J543 C K73 S 1NT 4H W No No N 3S 4S E No End N4S

3S is game-forcing, sets the suit and asks for a cue-bid. Once opener bids 4H responder knows both minor suit aces are missing.

Hand 4

N S 764 H 82 D Q8 C AQJ975 W S J85 H 93 D KT753 C KT2 E S A93 H QJ75 D J962 C 64 S S KQT2 H AKT64 D A4 C 83 S 1H 2S 3NT W No No No N 2C 3C No E No No End S3NT

After opener’s reverse N/S are in a game-forcing situation, so 3C cannot be passed. With little choice opener has to bid 3NT, at least as good as any other game contract.

Hand 5

N S A865 H 84 D K964 C QJ7 W S QT4 H KQJT75 D A5 C 86 E S J2 H 62 D 8732 C AT543 S S K973 H A93 D QJT C K92 S 1NT 2S W 2H No N Dbl No E No End S2S

Responder’s double is for take-out, not penalties. 2S is an easy make, as is 2H for E/W.

Hand 6

N S J75 H AK764 D K6 C 765 W S 92 H QT2 D QT5 C K9843 E S A843 H J983 D 932 C AJ S S KQT6 H 5 D AJ874 C QT2 S 1D 1S 2NT W No No No N 1H 2C No E No No End S2NT

2C is fourth-suit, NOT game-forcing, so when opener makes a minimum bid of 2NT he can safely pass.

Hand 7

N S KT983 H 93 D AJ8 C QT6 W S QJ2 H AJ2 D Q97 C AK93 E S 754 H 876 D 654 C J854 S S A6 H KQT54 D KT32 C 72 S 1H No W 1NT End N Dbl No E No No W1NT

Doubles after a NT bid are for penalties, and that is what North should bid here.

Hand 8

N S AKJT85 H 6 D KQ5 C KQ2 W S 73 H QT943 D A92 C 964 E S 642 H J D JT864 C JT83 S S Q9 H AK8752 D 73 C A75 S 1H 3H 4C (cue bid in support of spades) 5S (shows 2 key-cards and the queen of spades) W No No No No N 2S (game-forcing) 3S 4NT 6S E No No No End N6S

6S is an easy make.