UNBLOCKING THE TRUMP SUIT
As dealer, be careful to lead your trumps in such a manner that you will not find it impossible to continue the lead. The simplest method of unblocking the trump suit is to lead or play the high trumps from the shorter hand.
Occasionally to avoid blocking the suit, it will be necessary to “ruff” with a high instead of a lower trump. For instance, with ace and ten of trumps in dummy and king, queen, jack, nine and eight in your own hand, if you “ruff” with dummy’s ten, you will block the trump suit; even a temporary discontinuance of the trump lead may result in loss.
When you lead the queen toward the ace, holding the ace, jack, ten, nine, seven in one hand and queen, eight, four in the other, you must provide for the possible necessity for leading three times through the king by playing the nine of trumps on the queen lead. A careless play of the seven may make it impossible to capture the adversary’s king.