The singleton describes the fit

Daisy Donovan, an American-born English television presenter, actress and writer, said, “All Bridget Jones did was give us a word for it (living alone) — singleton — which was the worst possible thing.”

In bridge, though, being able to show a singleton is sometimes the best possible thing a player can do. Look at today's North hand. After South opens one heart, what should North respond?

The North hand is strong enough to force to game. It contains 14 support points (11 high-card and three for the singleton, given the known nine-card or better fit) and only seven losers (the number for a raise to game). If you use the Jacoby Forcing Raise, you could respond two no-trump, but it is much better to jump to four diamonds, a splinter bid announcing at least game-going values, four or more hearts and a singleton (or void) in diamonds.

That reduces South's losers to three: one spade, one heart and one club. He now knows that, if necessary,

he can ruff his low diamonds on the board. South then uses some form of Blackwood to find out that his partner has the missing aces and spade king (never splinter with a singleton king) and bids seven hearts.

After West leads the diamond king, how should South plan the play?

The only danger is a 4-0 trump split. If East has all four hearts, declarer is down. But if West has them, South is safe as long as he starts with his trump king (or queen), keeping dummy's ace and 10 over West's jack. When East shows out, declarer finesses in hearts through West and claims all the tricks via two spades, five hearts, one diamond and five clubs.