SIX POSITION CHESS DIAGNOSTIC SAMPLER
Prepared 21 October 2026

Start here
Print chess_diagnostic_large_print.pdf: one introduction page, then six large board diagrams, one per page. Use a physical chessboard or the diagrams. No installation, app, account or purchase is required. Take as long as you need. This is a practice diagnostic, not a chess rating test or an assessment of learning ability.

Keep chess_diagnostic_answer_key.pdf separate until you are ready to check your work. It has three pages with explanations and one suggested practice habit for each motif. The plain-text question and answer files give every piece's color, type and square so the exercise does not depend on interpreting an image.

Files
- chess_diagnostic_large_print.pdf: seven printable pages, with six 5.33-inch board diagrams and 16-point question text.
- chess_diagnostic_answer_key.pdf: standalone three-page answer key.
- six_positions_questions.pgn: six setup positions with questions and no solution moves.
- six_positions_answers.pgn: six annotated answers; exercise 5 includes both the mate and the stalemate branch.
- individual_pgn/: one question and one answer PGN per exercise, for viewers that handle a single game more easily.
- six_positions.fen: six FEN records, in exercise order.
- positions.json: piece setups, questions, answers and exact move sequences.
- questions_plain_text.txt and answer_key.txt: image-independent alternatives.
- chess_validation.json and validate_chess.py: machine-readable checks and reproducible validation code.
- sources.txt and font_license.txt: supporting sources and installed-font license notice.

Optional Pawnpetal route
The official App Store listing for Pawnpetal Chess: Play & Learn by Gal Itach says it can import PGN games and study variations. This package uses standard PGN SetUp and FEN tags because the exercises begin from constructed positions, not the normal starting board.

These files have NOT been tested in Pawnpetal on an iPhone or iPad. Support for setup positions, zero-move question games, multiple games, comments and variations has not been verified in the app. No exact button sequence or successful import is claimed. If you already have the app and want to try, start with an individual question PGN; if the board or side to move does not match the printed diagram, stop and use the paper route. Opening an answer PGN reveals solutions.

App use is voluntary. The listing currently requires iOS/iPadOS 18 or later. Installing an app can require an Apple Account, internet access and storage. The worksheet itself needs none of those. Do not sign into someone else's or a shared library device for this exercise.

App source, checked 21 October 2026:
https://apps.apple.com/us/app/pawnpetal-chess-play-learn/id6811392880

What was validated
All six FENs pass python-chess Board.is_valid(). Every supplied move in every answer line and PGN variation is legal and has matching standard algebraic notation. Specific checks verify the undefended bishop and absence of recapture, the knight fork and only reply, the absolute pin and illegal knight move, checkmate, stalemate, and protected promotion with its only reply. The 14 PGN files parse without errors.

The validator uses python-chess 1.999, which imports the chess module version 1.11.2, installed from standard PyPI. To rerun the checks in an environment with Python, install python-chess from PyPI if necessary, then run python validate_chess.py from this folder. That installation is only for optional revalidation, never for doing the worksheet.

Limits and provenance
These positions and explanations were constructed for this sampler rather than copied from a puzzle database, book or website. They illustrate familiar motifs; no claim is made that these positions have never appeared before. These are exercise questions, not engine-rated problems. There is no claim of unique-best play, optimal long-term strategy, fastest mate, historical reachability, classroom testing, Elo improvement or accessibility certification. Legal-move enumeration is sufficient for the bounded claims here; no engine or external tablebase was used. The PDFs are not tagged accessibility documents; use the plain-text piece lists when preferred.

Diagrams use DejaVu Sans chess glyphs from the installed font. The font's license notice is included. No puzzle or board images were downloaded.
