Effective from 1 July 2017
Approved by the 1982 General Assembly, amended by the General Assemblies of 1984 through 2016. 
0. 
Introduction 


A game played over the board will be rated by FIDE when it takes place in a FIDE registered tournament and meets all the following requirements. 


0.1 
The following regulations shall be altered by the General Assembly upon recommendation of the Qualification Commission (QC). Any such changes shall come into effect on 1st July of the year following the decision by the General Assembly. For tournaments, such changes will apply to those starting on or after that date. 


0.2 
The tournaments to be rated shall be preregistered by the federation that will be responsible for the submission of results and rating fees. The tournament and its playing schedule must be registered one week before the tournament starts. The QC Chairman may refuse to register a tournament. He may also allow a tournament to be rated even though it has been registered less than one week before the tournament starts. Tournaments where norms will be available must be registered 30 days in advance. 


0.3 
All arbiters of a FIDE rated tournament shall be licensed otherwise the tournament shall not be rated. 


0.4 
Tournament reports for all official FIDE and Continental events must be submitted and shall be rated. The Chief Arbiter is responsible for the results submitted. 


0.5 
FIDE reserves the right not to rate a specific tournament. The organizer of the tournament has the right to appeal to the QC. Such an appeal must be made within seven days of communicating the decision. 

1. 
Rate of Play 


1.1 
For a game to be rated each player must have the following minimum periods in which to complete all the moves, assuming the game lasts 60 moves.
Where at least one of the players in the game has a rating 2200 or higher, each player must have a minimum of 120 minutes.
Where at least one of the players in the game has a rating 1600 or higher, each player must have a minimum of 90 minutes.
Where both of the players in the game are rated below 1600, each player must have a minimum of 60 minutes. 


1.2 
Where a certain number of moves is specified in the first time control, it shall be 40 moves. 


1.3 
For a game to be rated on the Rapid list, each player must have more than ten minutes but less than sixty minutes. 


1.4 
For a game to be rated on the Blitz list, each player must have at least five but no more than ten minutes. 

2. 
Laws to be followed 


2.1 
Play must take place according to the FIDE Laws of Chess. 

3. 
Playing Time per Day 


3.1 
There must be no more than 12 hours play in one day. This is calculated based on games that last 60 moves, although games played using increments may last longer. 

4. 
Duration of the Tournament: 


4.1 
For tournaments, a period not greater than 90 days, except: 



4.11 
Leagues may be rated which last for a period greater than 90 days. 



4.12 
The QC may approve the rating of tournaments lasting more than 90 days. 



4.13 
For tournaments lasting more than 90 days, interim results must be reported on a monthly basis. 

5. 
Unplayed Games 


5.1 
Whether these occur because of forfeiture or any other reason, they are not counted. Any game where both players have made at least one move will be rated. 

6. 
Composition of the Tournament 


6.1 
If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded. Otherwise if an unrated player has played rated games, then this result is included in computing his overall rating. 


6.2 
In a roundrobin tournament at least onethird of the players must be rated. Subject to this requirement, 



6.21 
If the tournament has less than 10 players, at least 4 must be rated. 



6.22 
In a double roundrobin tournament with unrated participants, there must be at least 6 players, 4 of whom must be rated. 



6.23 
National Championships played as roundrobin shall be rated if at least 3 players (or 2 women in events exclusively for women) had official FIDE Ratings before the start of the tournament. 


6.3 
In a Swiss or Team Tournament: 



6.31 
For an unrated player’s first performance to count, he must score at least 1/2 point. 



6.32 
For rated players, only games against rated opponents are counted. 


6.4 
In the case of a roundrobin tournament where one or more games are unplayed, the results of the tournament must be reported for rating as if for a Swiss system tournament. 


6.5 
Where a match is over a specific number of games, those played after one player has won shall not be rated. 


6.6 
Matches in which one or both of the players are unrated shall not be rated. 

7. 
Official FIDE Rating List 


7.1 
On the first day of each month, the QC shall prepare a list which incorporates the rated play during the rating period into the previous list. This shall be done using the rating system formula. 



7.11 
The rating period (for new players, see 7.14) is the period where a certain rating list is valid. 



7.12 
The following data will be kept concerning each player whose rating is at least 1000 as of the current list:
FIDE title, Federation, Current Rating, ID Number, Number of games rated in the rating period, Date of Birth, Gender and the current value of K for the player. 



7.13 
The closing date for tournaments for a list is 3 days before the date of the list; tournaments ending before or on that day may be rated on the list.
Official FIDE events may be rated on the list even if they end on the last day before the list date. 



7.14 
A rating for a player new to the list shall be published only if it meets the following criteria: 



7.14a 
If based on results obtained under 6.3, a minimum of 5 games. 



7.14b 
If based on results obtained under 6.4, a minimum of 5 games played against rated opponents. 



7.14c 
The condition of a minimum of 5 games need not be met in one tournament. Results from other tournaments played within consecutive rating periods of not more than 26 months are pooled to obtain the initial rating. 



7.14d 
The rating is at least 1000. 



7.14e 
The rating is calculated using all his results as if they were played in one tournament (it is not published until he has played at least 5 games) by using all the rating data available. 


7.2 
Players who are not to be included on the list: 



7.21 
Players whose ratings drop below 1000 are listed on the next list as 'delisted'. Thereafter they are treated in the same manner as any other unrated player. 



7.22 
Titled players who are unrated are published in a separate list concurrently with the list of rated players. 



7.23 
Inactive players are considered rated at their most recent published rating for purposes of rating and title results. 



7.23a 
A player is considered to commence inactivity if he plays no rated games in a one year period. 



7.23b 
A player regains his activity if he plays at least one rated game in a period and he is then listed on the next list. 

8. 
The working of the FIDE Rating System 


The FIDE Rating system is a numerical system in which fractional scores are converted to rating differences and vice versa. Its function is to produce scientific measurement information of the best statistical quality. 


8.1 
The rating scale is an arbitrary one with a class interval set at 200 points. The tables that follow show the conversion of fractional score 'p' into rating difference 'dp'. For a zero or 1.0 score dp is necessarily indeterminate but is shown notionally as 800. The second table shows conversion of difference in rating 'D' into scoring probability 'PD' for the higher 'H' and the lower 'L' rated player respectively. Thus the two tables are effectively mirrorimages. 


8.1a 
The table of conversion from fractional score, p, into rating differences, dp
p 
dp 
p 
dp 
p 
dp 
p 
dp 
p 
dp 
p 
dp 
1.0 
800 
.83 
273 
.66 
117 
.49 
7 
.32 
133 
.15 
296 
.99 
677 
.82 
262 
.65 
110 
.48 
14 
.31 
141 
.14 
309 
.98 
589 
.81 
251 
.64 
102 
.47 
21 
.30 
149 
.13 
322 
.97 
538 
.80 
240 
.63 
95 
.46 
29 
.29 
158 
.12 
336 
.96 
501 
.79 
230 
.62 
87 
.45 
36 
.28 
166 
.11 
351 
.95 
470 
.78 
220 
.61 
80 
.44 
43 
.27 
175 
.10 
366 
.94 
444 
.77 
211 
.60 
72 
.43 
50 
.26 
184 
.09 
383 
.93 
422 
.76 
202 
.59 
65 
.42 
57 
.25 
193 
.08 
401 
.92 
401 
.75 
193 
.58 
57 
.41 
65 
.24 
202 
.07 
422 
.91 
383 
.74 
184 
.57 
50 
.40 
72 
.23 
211 
.06 
444 
.90 
366 
.73 
175 
.56 
43 
.39 
80 
.22 
220 
.05 
470 
.89 
351 
.72 
166 
.55 
36 
.38 
87 
.21 
230 
.04 
501 
.88 
336 
.71 
158 
.54 
29 
.37 
95 
.20 
240 
.03 
538 
.87 
322 
.70 
149 
.53 
21 
.36 
102 
.19 
251 
.02 
589 
.86 
309 
.69 
141 
.52 
14 
.35 
110 
.18 
262 
.01 
677 
.85 
296 
.68 
133 
.51 
7 
.34 
117 
.17 
273 
.00 
800 
.84 
284 
.67 
125 
.50 
0 
.33 
125 
.16 
284 





8.1b 
Table of conversion of difference in rating, D, into scoring probability PD, for the higher, H, and the lower, L, rated player respectively.
D 
PD 
D 
PD 
D 
PD 
D 
PD 
Rtg Dif 
H 
L 
Rtg Dif 
H 
L 
Rtg Dif 
H 
L 
Rtg Dif 
H 
L 
03 
.50 
.50 
9298 
.63 
.37 
198206 
.76 
.24 
345357 
.89 
.11 
410 
.51 
.49 
99106 
.64 
.36 
207215 
.77 
.23 
358374 
.90 
.10 
1117 
.52 
.48 
107113 
.65 
.35 
216225 
.78 
.22 
375391 
.91 
.09 
1825 
.53 
.47 
114121 
.66 
.34 
226235 
.79 
.21 
392411 
.92 
.08 
2632 
.54 
.46 
122129 
.67 
.33 
236245 
.80 
.20 
412432 
.93 
.07 
3339 
.55 
.45 
130137 
.68 
.32 
246256 
.81 
.19 
433456 
.94 
.06 
4046 
.56 
.44 
138145 
.69 
.31 
257267 
.82 
.18 
457484 
.95 
.05 
4753 
.57 
.43 
146153 
.70 
.30 
268278 
.83 
.17 
485517 
.96 
.04 
5461 
.58 
.42 
154162 
.71 
.29 
279290 
.84 
.16 
518559 
.97 
.03 
6268 
.59 
.41 
163170 
.72 
.28 
291302 
.85 
.15 
560619 
.98 
.02 
6976 
.60 
.40 
171179 
.73 
.27 
303315 
.86 
.14 
620735 
.99 
.01 
7783 
.61 
.39 
180188 
.74 
.26 
316328 
.87 
.13 
> 735 
1.0 
.00 
8491 
.62 
.38 
189197 
.75 
.25 
329344 
.88 
.12 






8.2 
Determining the Rating 'Ru' in a given event of a previously unrated player. 



8.21 
If an unrated player scores zero in his first event his score is disregarded.
First determine the average rating of his competition 'Rc'.
(a) In a Swiss or Team tournament: this is simply the average rating of his opponents.
(b) The results of both rated and unrated players in a roundrobin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows: 





(i) Determine the average rating of the rated players 'Rar'.
(ii) Determine p for each of the rated players against all their opponents.
Then determine dp for each of these players.
Then determine the average of these dp = 'dpa'.
(iii) 'n' is the number of opponents.
Ra = Rar  dpa x n/(n+1) 



8.22 
If he scores 50%, then Ru = Ra 



8.23 
If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50% 



8.24 
If he scores less than 50% in a Swiss or team tournament: Ru = Ra + dp 



8.25 
If he scores less than 50% in a roundrobin: Ru = Ra + dp x n/(n+1). 


8.3 
The Rating Rn which is to be published for a previously unrated player is then determined as if the new player had played all his games so far in one tournament. The initial rating is calculated using the total score against all opponents. It is rounded to the nearest whole number. 


8.4 
If an unrated player receives a published rating before a particular tournament in which he has played is rated, then he is rated as a rated player with his current rating, but in the rating of his opponents he is counted as an unrated player. 


8.5 
Determining the rating change for a rated player 



8.51 
For each game played against a rated player, determine the difference in rating between the player and his opponent, D. 



8.52 
If the opponent is unrated, then the rating is determined at the end of the event. This applies only to roundrobin tournaments. In other tournaments games against unrated opponents are not rated. 



8.53 
The provisional ratings of unrated players obtained from earlier tournaments are ignored. 



8.54 
A difference in rating of more than 400 points shall be counted for rating purposes as though it were a difference of 400 points. 



8.55 
(a) Use table 8.1(b) to determine the player’s score probability PD
(b) ΔR = score – PD. For each game, the score is 1, 0.5 or 0.
(c) ΣΔR x K = the Rating Change for a given tournament, or Rating period. 



8.56 
K is the development coefficient.
K = 40 for a player new to the rating list until he has completed events with at least 30 games.
K = 20 as long as a player's rating remains under 2400.
K = 10 once a player's published rating has reached 2400 and remains at that level subsequently, even if the rating drops below 2400.
K = 40 for all players until their 18th birthday, as long as their rating remains under 2300.
If the number of games (n) for a player on any list for a rating period multiplied by K (as defined above) exceeds 700, then K shall be the largest whole number such that K x n does not exceed 700. 



8.57 
The Rating Change is rounded to the nearest whole number. 0.5 is rounded up (whether the change is positive or negative). 



8.58 
Determining the Ratings in a roundrobin tournament.
Where unrated players take part, their ratings are determined by a process of iteration. These new ratings are then used to determine the rating change for the rated players.
Then the ΔR for each of the rated players for each game is determined using Ru(new) as if an established rating. 

9. 
Reporting Procedures 


9.1 
The Chief Arbiter of a FIDE registered tournament has to provide the tournament report (TRF file) within 7 days after the end of the tournament to the Rating Officer of the federation where the tournament took place. The Rating Officer shall be responsible for uploading the TRF file to the FIDE Rating Server not later than 30 days after the end of the tournament. 


9.2 
Results of all international competitions must be submitted for rating unless the original invitations have made it clear the event was not to be FIDE rated. The chief arbiter must also announce this to the players before the tournament starts. 


9.3 
Each national federation shall designate an official to coordinate and expedite qualification and rating matters. His name and details must be given to the FIDE Secretariat. 

10. 
Monitoring the Operation of the Rating System 


10.1 
One of the functions of Congress is to establish the policies under which FIDE titles and ratings are awarded. The function of the rating system is to produce scientific measurement information of the best statistical quality to enable Congress to award equal titles for equal proficiencies of players. Thus the rating system must be properly scientifically maintained and adjusted on both a short and long term basis. 


10.2 
The rating scale is arbitrary and open ended. Thus only differences in ratings have any statistical significance in terms of probability. Thus if the composition of the FIDE Rating pool were to change, the rating scale could drift with respect to the true proficiency of the players. It is a major objective to ensure the integrity of the system so that ratings of the same value from year to year represent the same proficiency of play. 


10.3 
Part of the responsibilities of the Rating System Administrator is to detect any drift in the rating scale. 

11. 
The requirements for the FIDE Rating System Administrator 


11.1 
A sufficient knowledge of statistical probability theory as it applies to measurements in the physical and behavioural sciences. 


11.2 
Ability to design the surveys described under 12.3; to interpret the results of the surveys; and to recommend the Qualification Commission whatever measures are needed to preserve the integrity of the rating system. 


11.3 
To be able to advise and assist any FIDE member federation in the establishment of a national rating system. 


11.4 
To display a level of objectivity comparable to that of a FIDE Arbiter. 

12. 
Some comments on the Rating system 


12.1 
The following formula gives a close approximation to tables 8.1a and 8.1b.
P = 1/(1 + 10^{D/400}). However the tables are used as shown. 


12.2 
Tables 8.1a and 8.1b are used precisely as shown, no extrapolations are made to establish a third significant figure. 


12.3 
K is used as a stabilising influence in the system. When K = 10, the rating turns over in approximately 70 games; K = 20, it is 35 games; K = 40, it is 18 games. 


12.4 
The system has been devised to enable players to verify their ratings readily. 

13. 
Inclusion in the Rating list 


13.1 
To be included in the FRL or FIDE Rapid/Blitz Rating Lists, a player must be registered through a national chess federation which is a member of FIDE. The Federation must not be temporarily or permanently excluded from membership. 


13.2 
It is the responsibility of national Federations to inform FIDE if players should not be included in the FRL. 


13.3 
Any player excluded from the rating list because he is unable to obtain membership of a national federation, may apply to FIDE for special dispensation to be included in the list. 