Pins is lesson 2 of 3 in Quick practice: forks, pins and skewers, a tactics course suited to players rated around 750 (beginners). A pin: a piece cannot move (or should not) because a more valuable piece stands behind it. It has 2 interactive exercises: 2 find-the-move puzzles. You play every move on a board and get feedback straight away. The lesson is free.
What this lesson explains
The knight on c6 is pinned: if it moved, the bishop would be attacking the king. Moving into check is illegal, so the knight is frozen.
What you practise
Pin the black knight to its king.
The knight is pinned to the king by your bishop. Pinned pieces can't run away: attack it!
Worked examples
The knight is pinned to the king by your bishop. Pinned pieces can't run away: attack it! The knight cannot escape and will be lost.
chessGM