After a very straightforward auction, West receives a spade lead against 3NT.  North has presumably led 4th highest from an honour so South plays the Queen.

Much as it may be tempting to win with the Ace, the opposition have hit Declarer's weak spot and he needs to hold up his Ace until the third round.

South continues with the King in order to unblock the suit, should Declarer win the second trick and then continues with his 10 which Declarer wins with his Ace.  Note that when North plays the 2 of spades on the second trick, Declarer (and partner) can tell he led from a five card suit.

Declarer has seven top tricks but needs two more for his contract.  Providing he finesses into the South hand, the 'safe hand' because South is now devoid of spades, he is home and dry.

By holding up his Ace of spades until the third round, Declarer effectively cut his opponents' communications.  Had he not done so, as soon as one or other defender got in, they would have continued to play spades and 3NT would have gone off.

On the above hand North-South quickly reach 3NT.  However, making it is not possible on good defence.

East leads the 6 of clubs which his partner wins with King and returns the five on which Declarer plays the Queen.

Much as it's tempting to win with the Ace, West should refrain from doing so.  From the play so far it's highly likely partner has one more club.  West has no entries so if he wins the second trick, his hand is isolated from the game.

From the bidding, North-South are marked with precisely 25-27 points which means West can calculate his partner has 9-11 so at least six more points after playing his King of clubs.  Therefore duck the club at trick 2 and wait for partner to get in to return his last club.  By playing the 2 of clubs on the second round, it should be obvious to partner that you have five clubs including the Ace as Declarer would hardly have played the Jack at trick 1 had he held AQJ!

Declarer cannot get nine tricks without knocking out the Ace of diamonds but as soon as East wins his Ace of diamonds, back comes his last club and 3NT goes one off instead of making.  Job done!

Looking at the East-West hands, with no intervention they would sail into 3NT.  West would open 1♦, East would respond 1♠, West would now rebid 2NT showing 17-18 points which East would raise to 3NT.  However, with intervention from the opposition, things are harder, especially if East doesn't bid.  A frustrated West may feel the best he can manage is a bid of 3♦.  Even with a takeout double, East can hardly bid 3NT with no stopper in clubs.

East is not strong enough to respond 2♠ as that would in any case imply a five-card suit.  A double showing 'values' is the answer.  Of course you sacrifice the opportunity to make a penalty double of 2♣ but this happens rarely and it is more beneficial to play the double as a desire to compete as in this example.

The double does not show anything specific but will normally imply holding the other major and will in this case show a bit of something as opposed to nothing.  If East passes and both North and South compete, West can be forgiven for thinking his partner holds very little and therefore continuing the bidding could be risky.

The double from East enables West to be a bit braver and with stops in both of the opposition's suits and in the knowledge that East holds at least seven or eight points, West can now stick his neck out and bid 3NT for which he is well rewarded as there are nine top tricks.

An opening bid of 1NT on 12-14 points is very descriptive to partner but also highly pre-emptive to the opposition.  Following are a few guidelines on how to compete against a 1NT opening.

With a balanced kind of hand and up to 14 points it is best to pass and defend.

With 15+ points make a penalty double.

The time to compete is on more unbalanced hands but playing strength and suit quality is more important than high card points.  Thus KQxxx x KJ10xx xx is better than Jxxxx Kx KJ10 AQx as despite fewer points, the hand has better distribution and concentration of values in the long suits.

Intervening is much more attractive based on shape rather than points and, as a result, many defences to 1NT have been developed over the years to be able to offer two suits rather than one.

There are different schools of thought as to when to compete against 1NT, some think you should do so at every opportunity while others are more discerning.  I belong to the latter school but whichever you decide, the fact remains there is always an element of risk, especially as second bidder as you don't know where the rest of the high card points are.  If the majority are with partner, competing will probably be right but if they are with the opposition, you may have landed yourself in trouble.

Looking at the above deal, after South opens 1NT, West has to decide whether or not to compete.  If you are playing a 'natural' defence, you would have to bid 2♠ and that would not be a good contract at all and if East tries to rescue into hearts, things only get worse!

However, if you are over cautious you will miss opportunities.  If you were to transpose the North and East hands, playing in spades would be excellent and you could make as many as ten tricks.

THE ASPTRO CONVENTION

Of the multitude of defences, Asptro is a good and flexible defence mechanism to an opening 1NT.  In its most simple form there are two artificial overcalls and two artifical responses.

An overcall of 2♣ promises hearts and another suit.  An overcall of 2♦ promises spades and another suit.  I would recommend you anchor to a five card major so a bid of 2♣ therefore promises at least five hearts and at least four of another suit.

Overcalls of 2♥, 2♠, 3♣ and 3♦ are all natural and should really be based on a 6 card suit.

As mentioned above, playing strength is more important than high card points but you would not have more than 14 as otherwise you would have doubled though you could have as few as 9 or even 8 if your hand was distributional, eg KQxxxx x x Kxxxx.  In principle however partner should expect you to be nearer to 11-14 points and at least 5-4 for an overcall of 2♣ or 2♦.

In many cases, partner will have a good idea where to play, game or part-score and with three or more of the major you have shown, he can bid it at the 2, 3 or 4 level depending on his hand.

There are two artificial bids on the other side of the table.  In response to an overcall of 2♦ (showing spades and another), partner may bid 2♥.  This does not necessarily mean he has a heart suit but simply denies having three or more spades.  Similarly 2♦ after an overcall of 2♣ denies having three or more hearts.  These bids are normally made on weak hands with no fit and no particular aspiration to go much further.

The other artifical bid is 2NT.  This is conventional and asking partner to bid his other suit.

The above hand is a good example of how this works.  West bids 2♦, nothing to do with diamonds but showing at least 5-4 in spades and another suit.  Clearly East does not want to play in spades but is happy to play in anything else.  He therefore bids 2NT which asks partner to bid his other suit.  It happens to be diamonds and 3♦ is a much more comfortable final contract than 2♠ (doubled) would have been.

The advantage of using a convention such as Asptro is that it enables you to show partner you have two playable suits and unless you have a 6 card suit (which you can bid naturally) or a two suited hand which you can show by bidding 2♣ or 2♦, it is often not worth intervening in the first place.  On the above hand, showing a single suit, rather than making partner aware you have two, is dangerous.  Being able to show two suits enables you to play in a good contract instead of a poor one.

A One No Trump Overcall promises two things:

1. 15-18 high card points

2. A stop in the opponents' bid suit

Ideally the hand will be balanced but not necessarily and occasionally might even have a singleton.

In the above example if North opens 1♦, 1♥ or 1♠, a bid of 1NT by East is fine but not if North opens 1♣ in which case East would be better to make a takeout double.

However, most players will be familiar with the above but perhaps not so familiar with a) how West would respond to the One No Trump overcall and b) how South would respond to partner's opening bid.

a)  How West would respond to his partner's 1NT overcall

This is relatively easy as East's 1NT is a good description of his hand.  There are three considerations for West

1. Do we definitely not have enough points for game (6 points or fewer)?

2. Is game a possibility (7-9 points)?

3. Do we have enough points for game (9/10 points upwards)?

1. If West has 6 or fewer points he will normally do one of two things, either pass or if he has a long suit of at least 5 cards, he may make a weak take-out by bidding that suit at the two level.

2. If West has 7-9 points, he will want to be in game if East's 1NT is upper range and in a part-score if East's 1NT is lower range.  With a flat hand West might bid 2NT inviting East to bid game with 17-18 points.  With a five card major, he will have to take a view whether to settle for a part-score or push on to game.

3. If West has 9/10+ points, game should be reached and he has three options.  

The first is to jump to three of a major if he has a five card suit.  This bid is forcing and asks partner to choose between 3NT or 4 of the major.

With a flat hand, West could jump to 3NT.  However, if West has a four card major it is worth investigating a 4-4 fit as you would with Stayman.  The way to do that is to cue bid opener's suit and ask East for more information.  In the above example if North had opened say 1♦ and East bid 1NT, West would bid 2♦ to which East would replay 2♥.  If West held a four card heart suit, he would bid 4♥, otherwise 3NT.

b) How South would respond to partner's opening bid

This is the bit that is different.  There are four likely scenarios:

1. Pass - This you would do with 0-8 points, no particular support for partner's suit and no 6 card suit of your own.

2. Support partner's suit - This you would normally do with 0-8 points and four of partner's suit.

3. Bid a new suit - This you would do with 0-8 points and a 6-card suit.  This is a weak bid and NOT forcing and normally opener would be expected to pass unless he is very strong.

4. Double - 9+ points.  This is a PENALTY double, not take-out.  If you have 9+ points and partner has opened, you have a minimum of 21 points between you, East has shown 15-18 points so there is precious little left for West to have and East playing in 1NT doubled is likely to be in for a rough time!

Stayman and Transfers opposite a 1NT overcall

By partnership agreement you can agree to play Stayman and Transfers after your partner has overcalled 1NT.  This can be very useful as it gives the partnership a number of options similar to those you have opposite an opening 1NT.  However, do not assume your partner is playing this unless you have specifically agreed it beforehand otherwise you could end up in a muddle!

A 'Trial Bid' is a game try by opener when the bidding has gone 1♥ - 2♥ or 1♠ - 2♠.  Opener will have a strong opening hand and bid a suit where game may depend on partner having help in it.  In other words Opener bids a weak suit where he is concerned he has too many losers.

In the above example North opens 1♥ which South raises to 2♥.  North has a fair hand but whether they should play in game or a part-score depends on how well the hand fits with partner and whether partner has a good raise or meagre raise to 2♥.

North therefore makes a 'Trial Bid' of 3♣, pinpointing his club weakness and asking if partner can help.  If so, partner could jump to 4♥ and if not, he would bid 3♥.

In this instance South can help as a singleton club is a useful holdng and, despite his minimal point count, South could make an enterprising jump to 4♥.  Note that if South's clubs and diamonds were transposed, he would not be able to provide any assistance in clubs and would bid 3♥.

With the hands fitting so well, despite minimal high card points, North-South can make 11 tricks, even 12 if the defence doesn't take a club trick in time.  However, with South's minors transposed, North-South would have three club losers and a diamond.

Trial bids are part of the Acol bidding system and very useful when opener has a game-going hand but whether or not game is to be reached is dependent on how the two hands fit together.

On the above hand, 4♥ is an excellent contract.  If South finds a diamond lead, the defence will collect three tricks but on a non-diamond lead, Declarer would get the opportunity to discard a losing diamond on a club and make an overtrick.

However, many players would reach a bad 3NT contract and go two off on a diamond lead.  The reason for this is that West would either not bother to show 'secondary preference' in hearts and give partner a choice of contracts.  The bidding will often go 1♥ - 1♠ - 2NT - 3NT.

The 3♥ bid is known as 'secondary preference'.  It shows three hearts and is 100% forcing.  The logic behind this being a forcing bid is that with four card support, West would have made a limit raise in hearts in the first place and when East rebids 2NT to show 17-18 points, this could easily be on a four card heart suit.  Therefore a bid of 3♥ by West is guaranteeing enough points for game and asking partner to bid 4♥ with a five-card suit and to otherwise bid 3NT (or even 3♠ with three card spade support, also 'secondary preference').

With East's hand, on his rebid, he has to make a choice between showing his five card heart suit or his point count.  The latter is more important as those who rebid 2♥ will be left to play there.

For those who bid to 3NT, on a lucky day the North and South hands would be transposed and they might not get a diamond lead and make 3NT with overtricks but why leave it to chance?

The other thing North-South might do in defence is to block the diamond suit and allow Declarer to get away with being in a bad contract.  The initial 4th highest lead would go to North's King and East's Ace (if Declarer ducks he advertises a problem).  When South gets in with the Ace of hearts he has to decide whether to continue with diamonds and if he decides on the Queen, North has to throw the Jack underneath which actually should not be a problem after the 4th highest lead!

For anyone playing Smith Peters, South would duck the first heart and win the second round, giving his partner an opportunity to 'peter' which indicates a liking of the opening lead.  South can then confidentally continue in diamonds and, if it's the Queen, North should know to play the Jack underneath.