Notation vs GrandArena

Notation is a chess coaching app that teaches you why — not just what. Every chess evaluation comes from Stockfish 18, running entirely on your device. Every pattern, weakness, and tactical motif is detected by hand-tuned on-device classifiers built on decades of coaching theory. The language model's only job is the last step: explaining what the analysis found, in plain English, like a coach sitting next to you. The chess is never generated. It's explained. THREE COACHING FRAMEWORKS Notation is the first chess app to operationalise multiple grandmaster-level coaching frameworks as deterministic measurement: • Dan Heisman's seven positional elements — Mobility, Vulnerability, Centre Control, Coordination, Speed, Time, Flexibility — measured per-position with super-GM baselines • Jeremy Silman's coaching emphasis frames — fifteen frames choosing what to teach at each moment • Jacob Aagaard's positional predicates — Where are the weaknesses? Which is the worst-placed piece? What's the opponent's plan? All computed on-device. All deterministic. The same principles human coaches have used for decades, encoded into classifiers that run before the language model ever sees the position. GAME REVIEW Every game gets a coherent on-device review — no API key needed, no internet, no cost. Template-driven narrative against the full coaching substrate. When you want depth, upgrade once with your own Anthropic or OpenAI API key, o ruse the On Device LLM with no additional costs and the richer review becomes the permanent artefact for that game. Nadia comments on at most six moments — only the ones worth learning from. PDF export of every review. PLAYER PROFILE Style axes — Aggression, Tactical Alertness, Positional Play, Endgame — derived from the substrate with confidence bands. The seven Heisman elements sit below as evidence. Full-screen iPad dashboard. PDF coaching report you could hand to a human coach. OPPONENT SCOUTING & MATCHUP REPORTS Scout reports surface the full eight-axis substrate on any opponent. How-to-play-against framing with concrete suggestions. Player-vs-opponent comparison across all axes with weakest-phase detection. SHADOW — YOUR CHESS TWIN Shadow learns how you play and saves checkpoints. Play yourself from six months ago. See how far you've come. Coming soon: calibrate Shadow to your real-life rivals by importing their games. PLAY ON YOUR PHYSICAL BOARD Pair with Chessnut Air, Pro, Go, Air+ and Move over Bluetooth. Notation tracks every move on real wood while Nadia coaches. PRIVACY BY DESIGN Stockfish on-device. All coaching classifiers on-device. Cohort baselines on-device. Optional cloud AI is bring-your-own-key — your Anthropic or OpenAI API key, your account, your data. We never see it. Leave the field blank and Notation works fully without it. IMPORT YOUR GAMES Connect Lichess or Chess.com. Import PGN files. Nadia analyses everything in the background. £2.99. One-off. No subscription. No ads. No tracking. Yours forever.

GrandArena is chess without the friction. Open it and play — no sign-up, no clutter, no lessons to sit through. Just the board. PLAY YOUR WAY • Play the computer — five levels, from a gentle start to a real fight. Untimed, offline, no account. • Pass & play — two players, one device. Perfect for the sofa. • Play online — rated real-time games with matchmaking, live clocks, and an ELO rating that means something. BUILT TO GET OUT OF YOUR WAY • The chessboard is always ad-free — paid or not. • Offline-first: the computer and pass-and-play work with no network and no account. • Clean, quiet design. Pick your piece set and board theme. • Sign in with email, Google, or Apple when you want to play online and keep your rating. ONLINE, DONE RIGHT • Fast matchmaking across 5+0, 10+0, and 3+2 time controls. • Real ratings, leaderboards, and full match history. • See where you rank — globally and in your country. FAIR PLAY • Anti-cheat protects rated games so your rating is earned. GrandArena is free. Ads appear only on non-gameplay screens, and a single one-time purchase removes them for good if you'd rather not see them — the board stays ad-free either way. Just chess. Play anyone.