Product transparency

Mainline is not another puzzle trainer, game analysis tool, or spaced-repetition deck. This app sits one layer up: it is the orchestration layer that decides what you should work on, with which resources, and why, then revises that plan continuously as you train and play.

Progress in Mainline means training signals: whether you are showing up, completing the planned work, keeping reviews healthy, and building skill estimates with uncertainty. Rating is noisy, and no activity here is treated as proven to cause rating gain.

The engagement layer exists because consistency is part of training. It uses forgiving reminders, capped streak cycles, and competence feedback to make practice easier to resume. It does not use ads, leaderboards, shame, unbreakable streaks, or paywalled training quality.

Every exclusion is a design decision with a reason.

• No LLM/AI at runtimeGenerative AI plays chess poorly and introduces opacity. Mainline uses deterministic algorithms and local Stockfish. You can verify every decision.
• No competing game platformLichess and Chess.com provide great play servers. Mainline connects to external platforms rather than replacing them.
• No hosted copyrighted contentBooks and courses are recommended and logged, never hosted. Mainline points you to resources you own.
• No social or multiplayerNo leaderboards, chat, or comparative rankings. Social comparison harms long-term practice habits.
• No self-reported skill diagnosisSelf-assessment in chess is prone to error. Mainline measures play behaviorally from your games and calibration puzzles.
• No infinite streaksUnbreakable streaks create loss aversion and burnout. Mainline caps streak cycles and forgives missed days.
• No global leaderboardsComparative leaderboards harm motivation for most learners. Mainline focuses strictly on personal training consistency.
• No puzzle volume chasingCorrelation between raw puzzle volume and rating is near zero. Spaced repetition and deliberate calculation matter more than quantity.
• No opening memorization for beginnersBeginner and intermediate games are decided by tactical blunders. Time is better spent on pattern recognition and calculation.

Every recommendation, methodology value, and claim on this page carries a grade: an unverified assumption can never pose as established fact.

Grade answers how strong the science is. A second axis, confidence, answers a different question: how much of your own data backs this specific call to you. The same Grade-A finding can land with low confidence, as when we know spaced repetition works but you've only imported three games. Or it can land with high confidence, well-backed by your own play. The distinction keeps a band prior from masquerading as a personalised verdict.