
Solution

1… Qb6 threatens Qxd4 and white cannot move or defend the knight adequately.
1… Qb6 “pins” the white knight since moving the knight would give black a discovered attack with the rook.
Structured Chess Training
1… Qb6 threatens Qxd4 and white cannot move or defend the knight adequately.
1… Qb6 “pins” the white knight since moving the knight would give black a discovered attack with the rook.