TRICK 2.--A should not continue the lead of diamonds; the weak hand
would “ruff.”
TRICK 3.--Z can exhaust the trumps and make the club suit, but will
then be left with two losing diamonds. Before attempting to get the
trumps out, he must allow Y to trump these losing cards.
TRICK 5.--Hasty play by the dealer at this point would incur a loss
of four or five tricks. If Y trumps with the eight of hearts, the
trump suit is blocked and Z has no way of obtaining the lead. Ruffing
with the ace enables the dealer to unblock the trump suit and make
the clubs.