Mainline, the chess trainer that studies your mistakes

Why it surfaced

Mainline replaces random puzzle practice with blunder drills drawn from a player’s own losses, spaced-repetition reviews, and rating-matched endgame work. It even shows an evidence grade and explains uncertainty for each block, while its local Stockfish analyzer is available in an open beta without sign-in.

An adaptive chess-training program that analyzes public Lichess or Chess.com games and builds daily sessions around recurring weaknesses.