With a Trump. When the winning declaration is a suit for trumps, the declarer’s first consideration upon getting into the lead must be whether or not to lead trumps. As a rule, the trumps should be led at once, so as to exhaust the adversaries; but there are exceptional cases, the principal ones being:—
Do not lead trumps from the strong trump hand if it would be to your advantage to put the other hand in the lead with a plain suit, so as to let the trump lead come from the weaker hand to the stronger, as when a finesse in trumps is desirable.
Do not lead trumps if you have no good plain suit, and can make more tricks by playing for a cross-ruff.
Do not lead trumps if the weaker hand can trump some of your losing cards first. It often happens that a losing trump can be used to win a trick before trumps are led.
At No-trump. The declarer’s first care in a no-trumper must be to select the suit that he will play for. Four simple rules cover this choice:—
1. Always lead from the weak hand to the strong if the suit is not already established.
2. Play for the suit in which you have the greatest number of cards between the two hands, because it will probably yield the greatest number of tricks.
3. If two suits are equal in number, play for the one in which you have the greatest number of cards massed in one hand. That is, if you have two suits of eight cards each, select the one that has six of those cards in one hand, in preference to the suit with four in each hand.
4. Everything else being equal, play for the suit which is shown in the Dummy, so as to conceal from the adversaries as long as possible the strength in your own hand.