Observed arrival · 2026-09-09
The Opening Almanac
A chess research tool that searches billions of human games for moves that work against the replies players actually choose.
Field notes
The Almanac models opening choices as a tree of human behavior: player moves carry frequencies, terminal positions inherit results from recorded games, and scores are propagated backward through the tree. Its preparation budget can place instructions at multiple positions instead of forcing one linear variation. The page says the underlying material covers 7.83 billion Lichess decisions, while also warning that pooled ratings, time controls, small samples, and rarely tested refutations limit what the estimates can prove.
Observed signals
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Editorial observations of this landing page, not a rating.
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