Margery Allingham, commenting on her crime solver Albert Campion, wrote, "He did not arrive at this conclusion by the decent process of quiet, logical deduction, nor yet by the blinding flash of glorious intuition, but by the shoddy, untidy process halfway between the two by which one usually gets to know things."

It is, of course, better to draw conclusions from logical deduction. In this deal, South is in four hearts. West leads the spade nine. How should East deduce the correct defense?

North made a game-invitational limit raise, showing four or more hearts, 10-12 support points (here, all high-card points, no short-suit points) and eight losers (here, two in each suit).

East knows that West has led a singleton or high from a doubleton ... but which?

East should ask himself, "If my partner has a singleton, how many spades does that give declarer?" Here, the answer is five. And would South have opened one heart with five spades in his hand? It would have been most unlikely, because with 5-5 in the majors, South would have opened one spade, not one heart.

So East should deduce that his partner has led from a doubleton and should signal encouragement with his spade seven.

South wins, cashes the heart ace, and plays another heart. But West wins with his king, leads his second spade, receives a spade ruff and cashes the diamond ace for down one.

Note finally that declarer does best to call for dummy's spade king at trick one, making it more likely that East will have a reflex reaction and win with his ace.