A pin restricts a piece because moving it exposes a more valuable target behind it.
Three ideas to understand
- An absolute pin to the king makes the pinned move illegal.
- A relative pin still permits movement, though doing so may lose material.
- Confirm the tactical idea with a complete legality and blunder check before playing it.
Work through a concrete example
A bishop on b5 can pin a knight c6 to a king e8 along the diagonal.
Show answer
The c6 knight is shielding the e8 king from the b5 bishop. Moving it would leave its own king in check.
A reliable thinking process
Start with checks, captures and direct threats, but calculate the opponent's most forcing reply at every step. Track which piece becomes loose after each move and reconstruct the final position before deciding the combination works. A tactical motif is a clue for where to calculate, not proof that a sacrifice is sound.
Common mistake
Treating every pinned piece as immobile overlooks legal tactical resources.
Practice drill
Create one absolute and one relative pin, then list the pinned piece's legal moves.
Check your understanding
Can the opponent refuse the idea, answer with check, or insert a stronger capture? State the material and king-safety result at the end of the main line, not immediately after the attractive first move.
Take it into your next game
Save one representative position and review it briefly before your next playing session. During the game, do not search for an identical diagram; watch for the same relationship between pieces, squares and pawn structure. Mark the moment when the idea first became relevant, even if you chose another plan. After the game, compare your decision with the lesson and write one adjustment for the next session. This transfer step is more valuable than rereading the article without making a decision.
Finally, explain the position in one sentence without using the lesson title. If the explanation names the relevant squares, pieces and consequence, you understand the idea rather than only recognizing its label. Continue with the related lesson and compare the decision process.