> TL;DR: According to 5.5 years of data from 2.3 million players and 450 million games, most beginners will improve their rating by 100 lichess elo points in 3-6 months. Most "experienced" chess players in the 1400-1800 rating range will take 3-4 years to improve their rating by 100 lichess elo points. There's no strong evidence that playing more games makes you improve quicker.