Tricks AB, 2
YZ, 7
9. B Z A Y↷
4♠ 4♥ Qn♣ Qn♦
Trick 10.
Tricks AB, 2
YZ, 8
10. B Z A↷ Y
6♥ 5♥ 8♠ 10♠
Trick 11.
Tricks AB, 3
YZ, 8
11. B Z A Y↷
7♥ 8♥ 9♠ 5♠
Remark (Trick 11).—Y leads the losing spade to put the lead into A's hand (see fall of the spades, Tricks 1, 4, and 10), and so compel A to lead hearts up to Z. At this score (YZ, one) this is the best chance of four by cards. If the score were YZ, love, Y should lead a heart, as leading the spade gives up all chance of five by cards.
Tricks 12 and 13.—Z has ace, queen of hearts; and
YZ win four by cards.