Tricks AB, 1
YZ, 1
2. B Z A↷ Y
4♦ 7♦ Knv♦ Kg♦

Trick 3.

Tricks AB, 2
YZ, 1
3. B Z A Y↷
A♥ 5♥ 10♥ 6♥

Trick 4.

Tricks AB, 2
YZ, 2
4. B↷ Z A Y
10♦ 4♥ 5♦ Knv♣

Remarks (Tricks 3 and 4).—Y leads fourth-best; Z echoes; but as the cards lie, it so happens that the position of the hearts would be independently marked after Trick 5.