When the dealer seems backward about leading trumps, the inference is
that he is trying to establish a ruff in the weak trump hand, and you
should be on the alert to prevent this by leading trumps (through the
strength). It may be necessary for you to lead the trump after your
initial lead. It may be advisable to stop leading a suit, which would
help to establish a ruff in the weak hand; or it may be essential
that you try to place your partner in the lead, so that he can lead
the trumps through the strong hand. If you are weak in dummy’s long
suit, it is always more or less dangerous to lead trumps. When this
is the case, your lead might help the dealer to exhaust trumps and
make this long suit.