Training notebook · Tactics
Pin or skewer? Train the difference that changes your calculation
A pin asks what happens if the front piece moves. A skewer asks where that front piece can go. This distinction gives you a practical way to calculate beyond merely recognising aligned pieces.
A position to work through
Calculate a candidate continuation without moving the pieces. Look for the tactical idea, consider the opponent’s reply, then compare your calculation with the recorded line.
Black to move
Compare with the recorded continuation
Bc5 · Be3 · Bxd4
This is a line from the training source, not a claim that every alternative has the same outcome. Calculate the opponent’s reply before revealing it.
Lichess CC0 puzzle database; position from Brass Pawn’s curated training data
Read the line in the correct direction
Trace a rook's file or rank, or a bishop's diagonal, from the attacker through the first opposing piece to the piece behind it. In a typical pin, moving the front piece exposes something more valuable. In a typical skewer, the front target is more valuable and its retreat exposes the rear target.
A king behind the front piece creates an absolute pin: that piece cannot legally uncover check. A queen behind it creates a relative pin; moving may be costly, but it can still be legal and sometimes strong.
Test how the defender breaks the alignment
Do not count a pinned piece as immobile without qualification. It may move along the attacking line, capture the attacker, or participate in a legal exchange. With a relative pin, a counterattack against your king can outweigh the threatened queen.
Against a skewer, examine every retreat that also protects the rear piece, attacks the line piece, or gives check. The front target may escape in a way that prevents collection. Your calculation needs the second move, not just the attractive alignment.
Choose an exercise that tests decisions
A useful comparison set mixes pins and skewers without announcing the label. For each position, decide whether to increase pressure, capture immediately, move the attacker closer, or abandon the idea. The objective is a decision with a reason, rather than a vocabulary quiz.
When the engine rejects your move, inspect the earliest defensive reply that changes the story. Often the classification was right but the timing was wrong: the opponent could exchange the attacker or move the valuable piece before your threat became forcing.
Separate capture legality from recapture support
An absolutely pinned rook, bishop or queen may capture the pinning piece if that capture follows its legal movement and leaves its king safe. A knight cannot capture its own pinner in an ordinary absolute line pin: its jump would leave the pin line open. First establish legality; then assess whether the capture is worthwhile. The pinner's support is a separate question: an enemy recapture may make a legal capture unprofitable. With a skewer, also check whether the front target retreats with tempo. Reconstruct the resulting line after every exchange rather than retaining the original picture.
Sort legal movement from sensible movement
Make two columns headed 'front piece can legally move' and 'front piece should move'. Put eight examples into them before solving. The columns need not agree.
For each successful solution, describe the defender's best attempt to break the line. Then return to one failed example and find a safer move for the attacking side. This prevents the common training mistake of believing every pin or skewer must yield an immediate material win.
Put the practice into a routine
Where Brass Pawn fits
Brass Pawn includes motif-tagged tactics and local engine analysis. Its existing tactics overview explains the patterns; use this diagnostic routine to practise deciding when a line attack actually works. It does not guarantee that every alignment contains a combination.