Remark (Trick 2).—B has the five of spades, and Y the king. A, therefore, does not continue the trump, but leaves the small spade in his partner's hand.
Trick 3.
Tricks AB, 3
YZ, 0
3. Y B Z A↷
3♦ Kg♦ 2♦ 7♦
Trick 4.
Tricks AB, 4
YZ, 0
4. Y B↷ Z A
6♦ 10♦ 4♦ Qn♦
Trick 5.