Disclaimer

Last updated: September 2026. Please read this page carefully before using our calculators.

Educational information only

All content on ChessOpenings — calculators, articles, tables, and examples — is published for general educational purposes. It is not opening theory advice and is not a substitute for a qualified professional. We are not a coach for personalized repertoire decisionss, and no client or advisory relationship is created by your use of this Site.

Opening theory evolves with engine analysis: sidelines once "refuted" get rehabilitated, and evaluation depths shift. The move sequences here are mainline-correct at club level; deep novelties live in theory databases, not beginner tables.

Memorizing lines without understanding ideas fails at the first novelty — every entry leads with the idea. Naming conventions vary (some lines carry multiple names); this database uses the most common English club usage.

Accuracy of calculations

We implement well-known, publicly documented formulas (see the methodology section on each calculator page and established opening theory and master-practice statistics as applicable). Even correctly implemented formulas produce estimates that depend on your inputs and assumptions. Real-world outcomes vary. Do not rely on a single web tool for a consequential decision.

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Errors and corrections

If you spot an error, please email hello@chessopenings.app with the inputs you used. Verified corrections are published promptly.