A Flannery hand opens Two Diamonds with five Hearts and four Spades and 11 to 15 HCP’s.
The bidding: South, not playing Flannery, with 13 HCP’s, opens One Heart. West has an opening hand, but with five of his opponent’s suit, he does not have a bid. West passes because a double asks partner to bid Spades with four of them, and a Two Heart bid is a direct cuebid showing five Spades and five of a minor.
North bids a forcing No Trump showing 5 to 12 HCP’s denying four Spades and four Hearts. Partner cannot pass and must bid his second longest suit. In this case, his hand is not strong enough for a reverse, so he cannot bid Two Spades. Instead, he must bid his better (longer) minor, Clubs. North has 5 to 9 HCP’s and passes partner at the two-level.
The Play: West wants to lead a low trump because he has length and values in Hearts and he is afraid they will be ruffed out. South actually does not want to ruff Hearts because those are long hand ruffs which do not gain a trick while short hand ruffs do.
However, there are two trump holdings, one never makes an opening lead from, a singleton or Qxx. Since West has the latter, he makes the natural lead of the Diamond Ace from Ace King. Partner plays the Diamond Six showing an even number, and West, suspecting declarer has a singleton, does not cash the King.
Seeing the Club Ace and King in dummy, he switches to a low trump because he does not want declarer to get short-hand Diamond ruffs.
Declarer wins the Club Ace and plays the Diamond Jack. He does not cash either Heart honour because he does not want the defenders making him ruff in the long trump hand. He will pitch a Spade later.
East does not cover so declarer lets it ride and West wins the King and leads another low trump. Declarer wins the Club King and places the Diamond Ten on the table and East ducks again. Declarer sluffs a heart and the Ten wins. He plays the Diamond Nine and East covers. Declarer ruffs with the last trump in dummy. He then cashes both Heart honours in his hand, pitching a Spade from Dummy.
Declarer cashes the Spade Ace and ruffs a Spade and plays his good diamonds. West can ruff in when he wants. Declarer will lose no Spades, no Hearts, two Diamonds and one Club, making Two Clubs plus two for +130.
Note: If South opened Two Diamonds, Flannery, North would not be so fortunate playing a major. So Forcing No Trump got South to the correct minor contract.