TIPS FOR IMPROVERS
Points of interest from the April 2014 duplicates
1 Exclusion Key Card a.k.a Voidwood
Board 7 Tuesday 22 April – Vulnerability Amber – Dealer South
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None
AKQx
KJxxx
J10xx
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AQxx
J98xx
Qxx
x
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1098xxx
10xx
109
xx
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KJx
x
Axx
AKQxxx
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North
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East
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South
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West
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1 Diamond
5 Spades
7 Clubs
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Pass
Pass
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1 Club
3 Clubs
5NT
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Pass
Pass
Pass
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When South jumps to 3 Clubs over North’s response of 1 Diamond North can be almost certain that a slam in Clubs is on the cards. However it is no use using ordinary Key Card Blackwood as the Ace of Spades in the South hand is of absolutely no use to North. Consequently North should jump to 5 Spades. This inexplicable jump to the five level shows a void in that suit and asks partner to show how many key cards he has OUTSIDE that suit. With 0 or 3 keycards he bids one step up – 5NT – with one keycard he bids two steps up – 6 Clubs – and with two keycards he bids three steps up – 6 Diamonds.
Here South responds the first step showing 3 keycards (he cannot have zero after his jump to 3 Clubs) and North can now jump straight to the Grand Slam in Clubs. Note that there is no need to ask about the Queen of trumps as there is a known 10 card fit and the odds of bringing in the suit even if the Queen were to be missing is 89 per cent as only Qxx offside will cause any problems.
Some of you might ask the question how will the bidding go if West overcalls 1 Heart. The correct auction is now:-
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North
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East
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South
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West
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3 Spades
4 Hearts
6 Clubs
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Pass
Pass
Pass
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1 Club
4 Diamonds
4NT
7 Clubs
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1 Heart
Pass
Pass
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where 3 Spades is a splinter bid, 4 Diamonds and 4 Hearts are cue-bids. Now when South bids 4NT RKCB North jumps to 6 Clubs to show 1 or 3 keycards and a void (which can only be in Spades after the earlier splinter).
2 Accepting the invitation with minimum points
Board 2 Wednesday 23 April – Vulnerability North South – Dealer East
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10xx
J98xxx
KJ
10x
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AQxx
xx
xxxx
AJx
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Kx
AKQ
AQ
Q97xxx
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J98x
10x
10xxxx
K8
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North
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East
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South
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West
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Pass
Pass
Pass
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2NT
3 Diamonds
6NT
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Pass
Pass
Pass
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3 Clubs
4NT
Pass
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Only one pair out of eight reached 6NT on the above hand because the other seven pairs failed to appreciate the power of a six card suit.
East opens 2NT, West employs Stayman and then bids a quantitative 4NT over the 2 Diamond denial. Although East has a minimum 20 points he should accept the invitation because of the six card Club suit. Although there is a small possibility that the hand is off the Ace and King of Clubs this is unlikely and whenever the long Club is opposite Ace to three or better then the slam is a good bet.
On West’s actual Club holding the slam is actually 95% certain to make and would only go down when South holds all four outstanding Clubs (a 5% chance).
To illustrate the principle suppose we change West’s Clubs from AJx to Axx. What is the probability of the contract making now? The contract will now make when the outstanding Clubs are:-
A) 2-2 = 40%
B) North having three Clubs = 25% (one half of the 3-1 breaks)
C) North having a singleton King = 6.25% (one quarter of the 3-1 breaks in the South hand)
Giving a total probability of 71.25% which is excellent odds to justify bidding a slam.
3 Change of Trump Suit for Slam
Board 16 Tuesday 29 April – Vulnerability East West – Dealer West
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AQx
Kxx
xxx
AKxx
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1098xx
xxx
Qxx
xx
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Kxx
Jx
KJ109x
xxx
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Jx
AQ109x
Ax
QJ109
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North
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East
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South
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West
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1NT
2 Hearts
3 Hearts
6 Clubs
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Pass
Pass
Pass
Pass
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2 Diamonds
3 Clubs
4 Diamonds
Pass
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Pass
Pass
Pass
Pass
Pass
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North opens a strong no-trump and South transfers into Hearts. South now shows his second suit by bidding 3 Clubs.
This gives North a problem. He has a dilemma between bidding 3 Hearts or raising to 4 Clubs. At this stage North does not know the extent of South’s ambitions on the hand. If South is simply bidding on a 5-5 nine count to explore whether the hand should be played in no-trumps or a suit contract then the hand should be played in Hearts eg if South has ♠x ♥AQxxx ♦xx ♣QJxxx. This is especially true at Pairs scoring when making ten or eleven tricks in Hearts will score better than eleven tricks in Clubs.
However if South has a stronger hand with 14 plus points (which is the minimum recommended to make a slam try on a balanced 2=5=2=4 distribution) then a slam is quite possible. Therefore the bid which keeps both possibilities in play so to speak is to temporize by bidding 3 Hearts.
Over 3 Hearts South is now able to cue-bid 4 Diamonds showing the Ace or King of Diamonds and an interest in slam.
Over 4 Diamonds North can now visualize a slam but should jump to 6 Clubs rather than use keycard for Hearts because as a rule a 4-4 trump fit almost always produces one more trick than a 5-3 fit.
The above hand aptly demonstrates this principle. On a Diamond lead to 6 Hearts the contract is dependent on the Spade finesse which fails and so 6 Hearts will not make. However on a Diamond lead to 6 Clubs after drawing trumps and discarding two of Dummy’s Diamonds on the Heart winners the Spade finesse is taken for the overtrick and not the contract.
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