WHEN TO TRUMP
If the adversary attempts to force your strong hand, it is usually advisable to accept the force. Only in rare cases does it pay to allow the opponent to continue the lead of his established suit.
At times you can afford to give the adversary one trick, knowing that, on the next lead, your weak hand can take the “ruff.”
With two trumps against you it is often good play to discard rather than to “ruff” with the commanding trump. But to gain by your play, you should hold a certain entry card in the suit that the adversary must lead.
With one trump against you, do not use your one remaining trump until the leader’s partner is exhausted in the leader’s suit.
If the adversary leads a suit which you can trump in either hand, the “ruff” should invariably be taken in the weak hand, and a discard made in the strong one.
You are sometimes in a position to know that if you trump, your adversary will overtrump. When the best card is led, it is usually good play to trump immediately and if possible with a card which will not unguard an honour in your own hand, but will force a high card from the opponent. If a suit is led, of which you hold the commanding card in the opposite hand, your best defence is to take a discard, which will prevent the adversary from making a high card later in the hand. If you can make no advantageous discard, your best play is to trump, especially if the trumps in your combined hands are in sequence, for, if the adversary wins the trick, his high trump will probably make in any case.