The bidding: South, with 13 HCP and five spades, opens one spade. North has five-card support, but is too strong to jump directly to four spades. With 9 to 12 high card points and a singleton or void, he double jump shifts into his singleton with a four heart bid. This is called a splinter bid.
The point range is a partnership agreement, but the 9-12 range ensures game opposite a minimum opening. The risk with stronger splinters is missing slam. With 13 or more high card points and a singleton or void, one can use Jacoby 2NT. This becomes the game forcing major raise with four card support and any distribution.
There may be a fear of being passed in a splinter bid, however one should adopt the mind set that a double jump shift is never weak because partner has already entered the bidding. Two of a major over a minor opening is the exception.
South, with wasted honours opposite partner’s shortness, places the contract no higher than game.
The contract: Four spades by South
The opening lead: The jack of hearts
East wins the ace and seeing a very strong club suit in dummy switches to a diamond. Once clubs are set up, declarer’s losers have a resting place.
Declarer wins the ace and plays a small trump towards the dummy. With three cards and the ace and king missing, there is a chance the honours crash. West jumps up with the king and the ace comes crashing down and declarer makes his contract.
West should hold up with the king unless, from the bidding, he is known to hold the king. If declarer was only missing the king, he would take the finesse.
The result: Four spades making for +420
With AKJ opposite a doubleton, declarer can take the finesse to pitch a losing heart. Unfortunately that was impossible here because a heart was led.