When I started playing chess I was very bad. Then one summer morning I decided to create an account on chess.com. I would play people then, if they played an opening that I liked I would learn it (by using chess.com 's databases) and improve. The also have an extensive amount of puzzles to learn tactics. about a year later I bought the platinum version of chess.com (which allowed me to have unlimited puzzles among other things) and my rating has now increased from 200 ELO to 1700 ELO.
