[eru]

> You could even just use computer to do near perfect theory openings and you can not charge any one for cheating here, and you can still gain more ELO there.

That would be hard to distinguish from someone memorizing an opening book. So hard to detect.

[lmohseni]

On lichess, it’s possible to compare your current game against a book. I feel like it’s really improved my understanding of opening theory.