Fortresses and perpetual check: saving the impossible

The key idea

Material only wins if it can be used. Checks that repeat with no escape, or a wall the opponent can't cross, are worth a draw — no matter how many pieces the other side has.

Example 1 · Perpetual check: the tireless queen

Black has two rooks and a pawn one square from queening. At the normal pace, White loses without remedy. Watch what happens when the queen never stops giving check.

1. Qg5+ The only move that saves the game. Every tempo without check is b1=Q and a lost game — so there won't be a single tempo without check. And notice the detail that holds up everything else: Black's own rook on f8 blocks its own king's only escape door. Their pieces are in their own way.
2. Kh8 Black's king has only the corner left: f8 is occupied by its own rook. This is the fine detail of the perpetual — it's not enough to give check, you have to confirm the escape doors are CLOSED. Here Black itself closes them.
3. Qf6+ Second check, along the long diagonal. The king in the corner has no squares: g8 is the only way out.
4. Kg8 Back again. Sound familiar? It's a pendulum.
5. Qg5+ And again. Black, with its two rooks and its pawn on b2, can do NOTHING: it's condemned to answer checks for the rest of the game.
6. Kh8 The pendulum, back to the corner.
7. Qf6+ A draw by repetition. All of Black's material advantage is worth zero because it will never get a free turn to use it. Before resigning a lost position, ALWAYS ask yourself: does my queen have checks that never run out? The answer saves more games than you'd think.

Example 2 · The corner fortress: the bishop that doesn't count

Black has an extra king, pawn and bishop. And can't win: the pawn is a rook pawn and the bishop doesn't control the queening square. Watch chess's most famous fortress.

1. Ka1 The whole defense fits in one idea: the a1 corner. The pawn's queening square is DARK, and Black's bishop moves on LIGHT squares: it will never be able to attack a1 or drive your king out of there. If the bishop were dark-squared, this would be lost without remedy — check it yourself once the lesson is over.
2. a3 The pawn advances, convinced it's headed to become a queen.
3. Kb1 The king strolls between a1 and b1. It needs to do nothing else for the rest of the game: no black piece can touch either of those squares.
4. a2+ Check, and it looks like the beginning of the end. It's exactly the opposite: the pawn has just walked into the wolf's mouth.
5. Ka1 The king returns to the corner and the trap is set. Think about it from Black's side: its pawn needs to stand on a1, which is occupied by our king… and our king can't be driven out of there. There's only one way left to try: bring the king closer. And what happens if it does?
6. Kc2 Stalemate. White's king is not in check and has not a single legal square: a2 and b1 are covered by the pawn together with its own king, b2 is covered by Black's king. A draw. An extra king, bishop and pawn — and half a point for the defender. Whenever it's your turn to suffer through an endgame like this, check two things first: is the pawn a rook pawn? is the bishop the OPPOSITE color to the queening square? If both answers are yes, run your king to the corner: defeat doesn't exist in there.

Practice

You play White and you're lost: two rooks against you and a black pawn one square from queening. Your only way out is that Black's king never breathes freely again. Prove it.

1. The only path: check, NOW. One single tempo of rest and Black queens on b1. Notice: its own rook on f8 seals its escape door. Any move that isn't check loses to b1=Q. Look for the queen check along the g-file — and notice f8: its own rook blocks it.
2. Along the long diagonal. The king in the corner can only go back to g8: the pendulum is running. The king is in the corner: check it along the long diagonal. Your queen delivers it from f6.
3. Again. Black strolls its rooks around the board… mentally, because actually moving them, it won't be doing any more of that. Repeat the mechanism: check on g5. There's no other plan than this — and none is needed.
4. Repetition: a draw. You just rescued half a point from a dead position. The opponent's material only counts if one day they can use it — and that day isn't coming. Close the pendulum: the same check along the diagonal. A draw by repetition.

Half a point pulled out of the bottom of the pit. The perpetual and the fortress are chess's last line of defense: they don't show up in every game, but the day they do, they're worth as much as a brilliant combination. From now on, before resigning, you'll ask both questions: are there eternal checks? is there a wall? Often the answer is yes.