TRICKS 1 AND 2.--Z refuses to part with the ace of hearts,
and waits until B’s last heart has been played.
TRICK 4.--B cannot afford to win the queen of clubs with the
king. The dealer may have another club to lead. As the dummy holds no
card of entry, B hopes to block this suit by waiting until the last
club has been played from the dealer’s hand.
TRICK 5.--The dealer can, without doubt, make an extra trick
by playing the ace of clubs, but he imagines that the king of clubs
is with A.