Chess notation cheat-sheet (for new readers)
Pieces: K king · Q queen · R rook · B bishop · N knight · (a pawn move has no letter)
Actions: x takes · + check · # mate · O-O short castles · O-O-O long castles · e8=Q pawn promotes to queen
Annotations: ! good move · !! brilliant · ? mistake · ?? blunder
Catching the moment your own piece blocks the win
The hardest part of solving a clearance is admitting the obstacle is yours. A knight sits on the very square your queen wants. A rook occupies the file your other rook should own. The reflex is to scan the enemy camp for the trick, but in these positions the answer is on your own side, in a piece that has quietly stopped pulling its weight.
So flip your search order. Spot the square first, then the squatter. Ask which empty square would let a knight drop in for a fork or a queen plant itself next to the king, then check what of yours is standing on it. Watch for a freeing move that also gives check: the opponent has to answer, and that reply hands you the tempo to land the second piece. A bishop on the square a knight needs slides away with check, the opponent must respond, and on the next move the knight arrives and forks king and queen. The check buys the time; the vacated square cashes the threat.
The trainer feeds you positions where the blocking piece is one of your own, so the habit of looking inward becomes the first thing you do at the board.
Spotting when a line wants to be opened, not occupied
The other thing to recognize is that you are not always freeing a square to stand on. Sometimes you are opening a file, rank, or diagonal so a long-range piece can run down it, and the tell is different.
Open diagonal. When your queen and the enemy king sit on the same diagonal with one of your own pawns or bishops between them, that blocker is the move. It steps aside and the queen rakes through to the king.
Stacked rooks. A rook on a half-open file with a second rook or the queen behind it is a clearance waiting to happen: the front piece lifts off and the one behind slams toward the back rank.
The Bristol track. Train your eye for one of your line-pieces moving off a line so a second line-piece can travel that same line behind it; the lead piece captures nothing, it just vacates the track. Named from an 1861 problem tourney, it is rare enough that you will mostly meet it in the harder rating bands, so push the slider up if you want to drill it. The clearing move is often a sacrifice, because the open line matters more than the wood.
Weighing the square against the material before you commit
Not every blocking piece is worth throwing away, and the trainer rewards you for checking. The judgment call is whether the cleared square or line produces a threat worth more than the material spent. A clearance sacrifice pays off when the piece that arrives delivers mate, wins back more than it cost, or sets up a fork that nets a heavier piece.
Work backward in the position. Picture the finish first: a knight planted on a fork square, a queen next to the king, a rook ripping down an open file. Then ask what is in the way and what removing it would cost. If the obstacle moves with check, you usually get the move you need for free, and the line becomes forcing rather than a gamble; if it does not, count the captures to the end before you trust it.
I lean on the rating slider here, nudging it past the comfort point so the positions stop being obvious and the cost-versus-threat math gets real. Miss one, and the three free hints, motif first, then the piece, then the move, point you back without handing over the answer. Every position is computer-verified and pulled from real games, so the cleared square is always one a strong engine has confirmed. If you want the underlying theory rather than the drilling, clearance is the mirror of interference, where instead you block an enemy line.