In the endgame, the board clears. With fewer pieces on the board, the absolute power of the King (which hides in the opening) becomes a fighting machine. Endgame puzzles teach you king activity —a concept that alone can raise your rating by 200 points.

Set up the diagrams from your PDF on a physical chess board. Play both sides. If the puzzle is "White to Win," play Black's best defense. This teaches resilience.

Go back to puzzles you solved incorrectly 7 days ago. Use a flashcard app (Anki) to import the diagrams. The PDF acts as your master database.

Books by José Raúl Capablanca ( Chess Fundamentals ) and Wilhelm Steinitz are in the public domain. You can download legal PDFs of these masters' endgame chapters. Search for "Capablanca endgame lessons PDF."

While not free, these platforms offer sample PDF chapters. Sign up for newsletters—they frequently give away "5 Essential Endgame Puzzles PDF" as lead magnets.

Many national chess federations (like USCF or the English Chess Federation) release free training booklets. Search for "USCF endgame booklet PDF" or "ECF endgame puzzles."

Check your local chess club’s website or the Internet Archive (archive.org) for "Chess Endgame Training for Amateurs" – a 120-page PDF rated 4.8/5 by club players.