http://www.chess.com/tactics/players.html?sortby=attempt_count
Not necessarily done all them though, I think some new ones were added recently, possible that he/she didn't do those yet, and has just repeated the older ones.
Has anyone...
Sort:
I was on a mission to do them all. I was doing like 25-50 EVERY DAY for like 2 months! However, then I realized they add like 100-200 puzzles every week, so it's practically impossible to do them all if you're trying to learn at least a little bit from each puzzle.
... worked through all 21,254 puzzles on the tactics trainer feature? What rating did you achieve?