Engine analysis

The Next Move Solver, the Notation Converter and the Play vs Computer page use Stockfish 10, compiled to JavaScript and running in your browser. It is far stronger than any human player, but it is older and slower than current desktop versions of Stockfish, and the result depends on how deep it searches and how fast your device is. Two engines, or the same engine at different depths, can prefer different moves. Evaluations are estimates, not proofs, except where the engine reports a forced mate. To see how to read these numbers, see Stockfish depth, evaluation and PV explained.

Rating calculations

The Elo calculator applies the standard Elo formula with FIDE K-factors. Official FIDE, national-federation and online ratings follow their own regulations, and online sites use Glicko-based systems, so your official change may differ. Only the rating body itself can tell you your official rating.

Educational content

Our guides are checked against the FIDE Laws of Chess and other cited sources, and every position is verified with a legal-move generator. Rules can still differ in casual play, in some national federations and on some websites (for example, time-control and draw-claim rules). If an official arbiter's decision or a platform's rules differ from our article, theirs apply.

Fair play

Nothing on this site may be used to get help during a game you are playing. That is cheating under the rules of FIDE and of every major chess platform, and accounts are closed for it. We accept no responsibility for misuse of the tools.

Advertising and external links

The site is funded by ads served by Google AdSense. We do not choose individual ads and do not endorse the products advertised. Links to other websites are given for convenience and further reading; we are not responsible for their content or availability. We do not accept payment for links or reviews.

Network access

The "unblocked" in Play Chess Unblocked means the page is simple and lightweight. We do not help anyone get around a school, workplace or other network filter, and you should follow the acceptable-use rules of the network you are on.

Questions

If you think something on the site is wrong, please contact us.