Rene Descartes, a French philosopher, mathematician and writer who spent most of his life in the Dutch Republic and died in 1650, said in a lecture, “And now we come to the two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge.”
At the bridge table, we gain an understanding of a deal primarily by using deduction — although some players also employ intuition.
If you wish to test your deductive powers, cover the West and South hands. The contract is three no-trump. West leads a fourth-highest heart two and declarer calls for dummy’s four. Would you put in the 10 or rise with the king? Why?
This is a trap deal for North and South. They have 29 high-card points, but cannot, in theory, make game. However, if any game is going to get through, it is three no-trump. Often, when dummy has the heart queen and East the king-10 over her, it is right for East to play his 10. But not in this instance. If South is permitted to take the first trick with his heart jack, he will then cash four clubs, four diamonds and the spade ace to score up an overtrick.
It is right to play the 10 when South has the ace, but is that possible?
No! If South had started with ace-low in hearts, he would have called for dummy’s queen, hoping the lead was away from the king.
So East should play his king at the first trick, confident it will win, then return the five, his original fourth-highest. The defenders will run the suit for down one.