South has only 8 hcp, but 7 losers, and 3 points for a singleton.

North has 22 hcp with 5 losers, so is interested in game.

After South's replies, North calculates that South has at least 6 spades and possibly 7 losers, making 12 between them with the possibility of a small slam.

North uses Key-card Blackwood, to find that South has either an Ace of Diamonds, or the King of Spades.

East should not have led the Ace. Instead they should have led the 6♦, fourth from the longest suit, with a chance to break the contract.

After losing the first trick to the Ace of Diamonds, North will go on to draw all the trumps, and make 6 Spade tricks, 3 Hearts, 1 Diamond, and 2 Clubs. Slam made!

The problem for West was that there were only 11 immediate winners. There were potential winners with the opponents: two in spades, three in Diamonds and two in Clubs, if they could have been held back!

As North led the 2♣  (fourth from longest), followed by 5♣ , 7♣ , and fortunately won with 9♣ , it can be assummed that there were only three left in North and one in South. Note that a similar overall result would have happened if the 3♠  had been led.

The stragegy was to watch what the opponents discard, when the Hearts were run out by Declarer.

If North discarded another Club, then Declarer could make 13 tricks.

The contract could only have been defeated in the unlikely event that South retained Spades (discarded a Clubs and Diamonds), and North retained Clubs (discarded Spades).

Congratulations to Frank and Jean on succeeding with a once-in-a-lifetime opportunity! 

You wish to play in Hearts.

Play the 9♣ , which is asking for the higher of the other two suits. As you can see Dummy's k♥, win with the Q♥, then the A♥ , and finally A♣  to break the contract.

This is a "McKenny Discard". It asks partner for the higher of the two other suits, i.e. Spades were played and you showed a Club. The other two suits were Diamonds and Hearts.

Low value cards: 2, 3, 4, 5 ask for the lower suit (in this case Diamonds), and 7, 8, 9, 10 ask for thhigher (in this case Hearts). Note the 6 is indeterminate.

East will make 12 tricks immediately.

South must count the discards made by partner in North.

If partner discards two hearts, South can calculate that East holds A♥, K♥  and only the J♥.

Therefore, the other two suits, diamonds and clubs are worth sacrificing.

1  West wins with the A♣ 

2  West wins with A♠ 

3  West wins with A♦ 

4 West loses the Q♥   This will fork the defence !!!

      First option, if North wins with K♥ , then East's J♥  is promoted

5  North will probably lead Q♣ , East ruffs with 3♠ 

6  East leads a 4♦ , and West ruffs with 4♠ 

7 West plays 2♥c, to win with the promoted J♥  in Dummy

8 East leads 5♦ , to ruff with the K♠ 

9 West leads the 5♠  to win with J♠ , then Q♠  and three remaining diamonds to make the slam 

      Second option, if North had ducked, then Q♥  will win giving the extra trick to compensate for a trick lost later

Play

This looks impossible as there appear to be two losers.

Declarer is North and Dummy is South.

East will certainly lead and win with the K§, and not wanting to open a red suit, leads and loses the Q§ to a ruff in Dummy with 2ª.

Dummy now draws the spade trumps in two rounds with the Kª and Jª.

Dummy attempts to drop the opponents’ Q¨, by playing 3¨ to the A¨ and returning the 2¨ to the K¨, and finally ruffing the 5¨ with the 10ª. Fortunately, this works, and the J¨ is promoted.

Declarer crosses to Dummy with 5§ which is ruffed by 4ª.

(If the Q¨ had not dropped, then Dummy would have to try a finesse with the Q©, but this would fail at West’s K©.)

Then play the J¨ and discard the 6©. Then win to the A©.

Cross ruff the remaining hearts and club.

The contract makes the slam.

To defeat the contract, West must sacrifice the Queen of Spades.

Declarer will then ruff a club trick, cross back to South with a diamond, and ruff another club trick.

But this will exhaust Dummy’s trumps and restore West's 8 of Spades into a natural trick, after West’s two of Spades falls to the King.

There is another trick in Clubs by West. The contract cannot succeed.

An explanation

This is a Take-Out Double.

Bidding

Many would open as North with 1

East doubles for a take-Out, South passes, and

West makes a jump response in the major with 2 .

North passes, and East with 6 losers, raises to 4 .

Play

East-West should make 4 .

West is Declarer and is on lead with Hearts as trumps. To make the contract, West, must win 6 of the last 7 tricks.

If West leads winners, North and South will each win a trump trick with their hearts.

West must cash the A♦, discarding the Qª from dummy (One trick).

Now West leads the J♣, and loses a trick to North’s singleton K♣.

North will lead a spade, and give the lead to East , with the Aª and a discard in West of the blocking A♣ (Two tricks).

Declarer draws the remaining trumps from East with the A© and discards the final blocking ♣.(Three tricks).

Then Declarer runs the remaining three little Clubs in East to make the contract (Six tricks and contract made).

After a contract is agreed in hearts by N/S (after outbidding clubs by E/W), Key-card Blackwood shows only one control missing.

North has opened with the six of spades.

The Ace of spades is currently the only entry into the Declarer's hand. If it is played, there is probably only one heart trick and two diamond tricks able to be made immediately: opponents would make at least five tricks and the contract would go down.

Dummy in East Plays the 4 of spades, South plays the King of spades, and West ducks with the 8 of spades: one trick away.

South leads the Queen of spades, West holds back with the ten, North plays the seven, and East plays the five: second trick away.

Unfortunately, South now leads the three of spades, and Declarer has to win with the Ace, but discards the Ace of hearts in East which was blocking: one trick won.

Next West leads the King of hearts and discards the Ace of diamonds which was blocking: second trick won.

Then West leads the Queen of hearts, and discards the King of diamonds which was also blocking: third trick won.

Finally West is able to run off six diamond tricks to make the contract.

How lucky is that!  🙂

At first it looks difficult. Although there are lots of winners, it is difficult to communicate between the hands.

All the tricks can be made from East.

Win the first trick with the A♠  in East (over your K♠  in West).

Then play the Q♠  and J♠  from East, while discarding the A♦  and K♦  in West.

Continue from East by playing the Q♦ , J♦ , and 10♦ , and discarding the A♣ , K♣ , and Q♣  in West.

Finally all the Clubs in East are winners.

It is important that East wins all the aces in West's hand; so no matter what the opponents lead, West should win it, with an ace.

There are four losers: a club, a diamond, and possibly two hearts.

Win with the ace of spades in West. East ruffs the 2 of spades, and returns to the remaining ace in West.

Seeing that the king and jack of spades are played, the 10 of spades is a winner. Play it to be ruffed by South, and discard the remaining diamond loser in West. One trick down.

Only a club and a heart can be lost. Draw the Ace and Jack of hearts with the king and queen.

Three tricks down, and the contract is made.

South has a 4 loser hand and !NT is likely to be an 8 loser hand; therefore, with 10 losers (18-12 = 6 overtricks), a slam is possible.

So, South should bid 4C, which is Gerber asking for aces.

North responds 2H, showing 2 aces.

South then bids 6H and makes the slam.

  E         S         W         N
 -            -          -         pass
pass    pass    2NT*    pass
4C*     pass    5C**     pass
6NT    pass    pass     pass

*  = Gerber
** = 4 Aces

A small slam for E/W, although the declarer will actuall make all 13 tricks!

Vulnerable NT
Vulnerable 3NT + 4
40+6(30)+500=720 points to E/W
But if bid a small slam 6NT + 1 an extra 500=1220 points (note if only 6 tricks = 1190)

However, to disrupt the contract
  E         S         W         N
 -            -          -         pass
pass    pass    2NT*     3D#
4C*     5D##    pass     pass
pass

#  = Disrupting the likely slam
## = Believing partner's hand was stronger than it actually was

If N/S bid 5D non-vulnerable doubled going down 4
Minus 100+200+200+300=800 points to E/W

This is a Psyche, which is perfectly legal (although illegal in some systems and tournaments), but a deliberate and gross mis-statement of honour strength and/or suit length. It is primarily to mislead or disrupt the opponents. It must be declared in the player's system card.
Systemic psyching is not permitted, i.e. the player's partner knows what it means! A Deviation or Psyche should be just as much a surprise for the bidder's partner as it is for their opponents.

Typical Bidding for 4H:
 N            E            S           W
  -             -            1C          pass
 2H          2S          3H         pass
 4H         pass       pass       pass

Surprisingly, it is not always best to lead a singleton.
If East leads the Jack of Clubs, North will make the contract with 620 match points.
East should have led the King of Spades, and the contract will go down one trick losing 100 match points.

Compare below.

Tricks with singleton lead:                                            Tricks with king of spades lead: 

1.            CJ            C3           C2           CK                           1.            SK           SA           S3           S6

2.            H2           H3           HA          H4                           2.            H5           H4           HK          H3

3.            H5           H8           HK          H7                           3.            HQ          H7           H9           H8

4.            HQ          HT           H9           S3                           4.            CK           CJ            C3           C2

5.            C4           S4           CA          CT                            5.            H2           HT           HA          S8

6.            D7           D2           DK          DA                          6.            CA          CT           C4           D3

7.            D6           D8           DJ           DQ                          7.            C6           CQ          C5           S4

8.            DT           D3           S7           D4                           8.            ST           S2           S5           S7

9.            S2           SK           SA           S8                            9.            S9           H6           SJ            C7

10.          C6           CQ          C5           S5                           10.          DQ          DA          D7           D2

11.          ST           S6           SQ          C7                           11.          SQ          C8           D4           HJ

12.          SJ            C8           S9           H6                           12.          DK          D5           D8           D9

13.          HJ           D5           C9           D9                           13.          DT           D6           C9           DJ

Actually 7 Diamonds, 7 Hearts, and 7NT could be made!

Bidding for 7D:
 W         N           E         S
pass    1D        pass     1H
pass    3D        pass     4NT*
pass    5S**     pass     5NT*

pass     6D       pass     pass

pass

* Keycard Blackwood on agreed Diamonds suit (last suit bid )

** Two Aces and King of Diamonds

Two Kings were with the opponents.

Tricks:    
1.      SJ    SA    S5    S2
2.      DA    D7    D2    D3
3.      D4    D8    DK    C4
4.      HA    H2    H7    H5
5.      H3    H4    HK    H6
6.      HQ    C2    S7    H9
7.      H8    C3    D5    HJ
8.      CA    C5    C8    C7
9.      C9    C6    CQ    CK
10.    SK    D9    S3    S4
11.    CJ    CT    D6    S8
12.    HT    S9    DJ    S6
13.    DQ   SQ    DT    ST

A small slam in Diamonds, but actually made 7 Diamond!

Bidding:

  W       N         E         S
pass    1S       pass    4C*    With opening points in North and 18 in South, a slam was on!
pass    5H**    pass    6C*
pass    6NT*** pass    7NT
pass    pass     pass

* Gerber (Slam bidding in NT asking for Aces and later for Kings)

** 1 Ace

*** 3 Kings

Hold all the Aces and all the Kings

Tricks:    
1.      C4    CT    CQ    CK
2.      SA    S3    S2    S4
3.      S7    S9    SK    S8
4.      SQ    SJ    ST    D3
5.      S6    C5    C3    D4
6.      S5    C8    H2    D6
7.      D5    D2    DQ    H5
8.      D7    C2    DA    D8
9.      DK    D9    H4    C6
10.    H6    H3    HJ    H9
11.    H8    HT    HK    HQ

Claim (in Show Menu) for the last two tricks, making 13 and the Grand slam!

Yes it is a small slam in 6NT.

Although 5 Diamonds by South could make, an optimal bid would be 3NT by South which should make 11 tricks. West should lead the K♣.

Try 1 Club, aiming to bid 2NT next showing 17/18 points.  North bids 1NT showing 6-9 points.  South bids 2NT - asking and North should bid 3NT (which makes).