Note that going from 1200 ELO to 1800 ELO is going from 18th percentile to 74th percentile. Pretty much any form of study over 6 months will get you that progress, because you'll have spent more time on chess than ~74% of players.
Going from 1800 ELO to 2400 ELO (74th percentile to 99th percentile) in 6 months would be a lot more interesting, because clearly your study habits are helping you progress faster than others.
A lot of being better than X% of people at something is just about spending more time doing it than X% of participants... Most professional video game players have 5,000 to 10,000 hours of experience in their game.
I have friends that have played on Lichess for years and never reached above 1400. How you study is much more important than how much you study. Analyzing different modes of study, as done in this blog post, is quite useful.
Yeah I got to 1650 rapid chess.com within 6 months (starting from basic knowledge of chess pieces moving). I was kinda told that 1800 rapid chess.com within a year of playing is kind of expected.
For people wondering, lichess inflates rating usually at lower level (since it starts at 1500 vs 1200 chess.com). Usually lichess ratings are inflated by 200-300 compared to chess.com which is a bit closer to FIDE ratings.
I don’t have hard data to back this up, but I do think that 1200 to 1800 on lichess in six months is very solid improvement, there’s a ton of accounts that have 10x+ my playtime and are rated below. It doesn’t seem to be just a time invested thing.
Going from 1800 ELO to 2400 ELO (74th percentile to 99th percentile) in 6 months would be a lot more interesting, because clearly your study habits are helping you progress faster than others.
A lot of being better than X% of people at something is just about spending more time doing it than X% of participants... Most professional video game players have 5,000 to 10,000 hours of experience in their game.
Source: https://lichess.org/stat/rating/distribution/rapid