How are the opening families and variations in insights defined?

Hi!
I really like the "two-level" opening filter into opening families and variations in the insights tool, it's much more useful than the "raw" eco codes that were used before, IIRC.

Just out of interest, how are they defined, e.g. is there some mapping from eco codes etc.? And which criteria were used to define them? Is there somewhere a complete list of families and variations to be found?

Thanks a lot!
jakk_o

Looks like it comes from here: github.com/lichess-org/chess-openings

All openings that lichess uses follow the format "Opening Family: Variation1, Variation2, Variation3" (If variations exist). In practice, only the first variation is kept. Everything up to the ':' is the Opening Family and everything up to the first ',' is the Opening Variation.

github.com/lichess-org/chess-openings for all openings that are used. However, it uses the general opening format and is not split by family and variation like what you're looking for. You'll have to split it yourself using the logic above.

Thanks, this is exactly what I was looking for!