Training notebook · Endgames
Key squares in pawn endings: give your king a target
Key squares turn a vague plan to push a pawn into a king destination. Practise reaching useful squares while checking rook-pawn and tempo exceptions.
Choose squares before pushes
A key square is a square whose occupation by the attacking king can secure the pawn's promotion under the relevant conditions. Its value comes from the resulting legal possibilities, not from a coloured diagram. Begin with the pawn's location, the defending king's access and the side to move.
For elementary king-and-pawn positions, reliable lessons show key-square patterns that depend on the pawn's rank. Learn a pattern together with its assumptions. Rook pawns require separate treatment because the edge of the board removes escape routes and can give the defender a promotion-corner refuge.
A destination can be inaccessible
Knowing a desirable square does not mean the king can reach it. The defending king may hold opposition, block a crossing or attack the pawn if the king walks away. Compare at least two routes and count the defender's moves along each route.
A common practical mistake is to advance the pawn merely because the king has no obvious forward move. That advance changes the geometry and may remove a reserve tempo. Ask whether a waiting king move keeps more options, and whether the pawn's new square creates a real threat rather than just looking closer to promotion.
Build a target-and-route worksheet
Select a key-square exercise in the official Lichess practice collection. Before revealing feedback, mark the target squares on paper and write a short route toward one of them. Add the defender's most restrictive response at each stage. Play the exercise, then switch sides and try to keep the king out.
On your second pass, explain the failure of the most tempting pawn push. Do not simply label it a draw or a mistake: identify the entry square or tempo it loses. Finally reflect the position across the board in a legal study setup and solve it again. The pawn's file changes while the underlying geometry remains comparable.
Recognise a completed lesson
A successful session ends with a conditional statement: if the king reaches this square while the pawn remains safe, this plan becomes possible. It should also name a condition that would break the conclusion, such as a rook pawn, a blocked route or a changed move order.
Keep the exercise diagram or source link beside that statement. Return after a gap and calculate from the starting position without moving pieces. If you can identify a target but not defend it against the opponent's reply, spend the next session on the route rather than learning another key-square pattern.
When a defending king attacks the pawn, pause the route calculation and check whether the attacker must return. A target square loses practical meaning if reaching it costs the pawn it was meant to support. Keep the pawn's safety on the worksheet beside the king's destination throughout the exercise.
Put the practice into a routine
Where Brass Pawn fits
Brass Pawn's small king-and-pawn catalogue gives practical follow-up against an engine. Use external key-square studies for variants not present among its 15 built-in endgame drills.