All five "killer" pieces.
what is the hardest chess.com achievement
In my opinion chatterbox (10k points) or puzzle addict (10k correct puzzles)
10 k points is not a big deal . If a user is active enough on the forums , they will eventually get it . But yeah it looks like a long path , if you constantly keep looking at your progress while trying to achieve it . Should just forget about it and the award would pop up one day
what is the hardest chess.com achievement