Ideachess

Ideachess is a free chess tactics training server that aims to help chess-lovers improve their game by solving online interactive checkmate and chess tactics puzzles. Over 100,000 chess puzzles are available organized by degree of difficulty. Registration is free, and allows you to track your chess training improvements with statistics and graphs, to evaluate your abilities by the Glicko Elo rating system, to have exercises assigned to you based on your actual strength, and to be included on our "best tacticians" rankings, plus much more.