After taking the first trick, study the dummy carefully in order to
see which suit may be led through advantageously. If there are two
suits to choose from, select the suit in which you are short, hoping
it may afford you an opportunity to make a small trump.
The fall of the cards will often indicate that your partner can
trump the second or third round of the suit you are leading. Before
giving him the ruff, consider that he will be compelled to lead, and
if there is no suit in dummy that he can lead to advantageously, it
is better for you to lead through the strength on the table than to
force your partner to lead up to the strong hand. Of course, if it
is necessary to save the game by all means give your partner the
ruff, but if, on the other hand, you hold the ace or guarded king
of trumps, _i.e._ a high card that will stop the adversary’s trump
lead, it is preferable to lead through dummy’s strength. Later you
can stop the trump lead and give your partner the ruff.