Frequently Asked Questions

Answers to common questions about Rook & Rating and the chess rules behind its calculators.

Is Rook & Rating free?

Yes. Every calculator and guide is free, with no account or download. The site is supported by advertising.

Do you look up my FIDE rating?

No. You enter ratings yourself, and nothing you enter is sent to our servers. See the Privacy Policy.

Will my calculated rating match the official list?

Usually within a point or two. FIDE uses its own expected-score table, rates all events in a period from the starting rating, and applies its own rounding.

Which K-factor applies to me?

40 if you have fewer than 30 rated games, or are under 18 this year and rated below 2300; 10 if your published rating has ever reached 2400; otherwise 20.

Does the calculator work for Chess.com or Lichess ratings?

Not exactly. Those servers use the Glicko-2 system, where the change depends on rating deviation as well as the result. Our Elo tool follows FIDE's rules.

What does the 400-point rule do?

For players rated below 2650, a rating difference larger than 400 is counted as 400, so beating a much weaker opponent still gains a few points.

Which performance rating method should I use?

FIDE's dp-table method for anything official, including norms. The exact method is the best measure of the event itself; the linear method is a quick approximation.

Can the norm calculator confirm a norm?

No. It shows the score needed for the performance. The arbiter checks the other requirements, such as titled and foreign opponents, and signs the certificate.

What is the difference between Buchholz and Sonneborn-Berger?

Buchholz adds up all your opponents' scores; Sonneborn-Berger counts only those you beat in full and those you drew with at half value.

How many rounds does my Swiss need?

At least log₂ of the number of players, rounded up: 6 for 33 to 64 players. Add one or two if you can, to reduce ties.

Is 45 minutes plus 15 seconds a standard time control?

Yes. Under the FIDE Laws it counts as 45 + 60 × 15 seconds = 60 minutes per player, the minimum for standard play.

Why did I lose rating points after a draw?

Because you were the higher-rated player and expected to score more than half a point. Against an opponent 100 points below you, your expected score is 0.64, so a draw at K = 20 costs about 2.8 points.

How are byes counted in tiebreaks?

It depends on the event's regulations. FIDE's 2023 tiebreak rules use a virtual opponent for unplayed games; many events also use Buchholz Cut-1 so that the lowest score, often from a bye or a withdrawn player, is discarded.

Can I use the site during a game?

No. Using external information during a game breaks the Laws of Chess. Use it between rounds where the event allows.

How do I report an error?

Email logan.luo@adsnova.cn with the calculator, your inputs and the result you expected. See the Contact page.