## GRADING

Club members' grades as assessed by the British Chess Federation and under the separate system operated by the Yorkshire Chess Association.

ECF LINK>> http://grading.bcfservices.org.uk/

ECF LINK>> http://grading.bcfservices.org.uk/

## THE CHESS RATING SYSTEM

**Here are club member's current E.C.F and (ELO) grades. Perhaps we should point out that some of these were assessed on very few games, as for most of us they can only be won by games played in the Derbyshire League. Consequently, quite a few of our players are not graded under this system. **

2010/11

210988J

Most chess players see rating lists, which may include their own name, and ponder what the rating numbers

are used for; what they mean; and how they are calculated.

The purpose of the rating system in chess is to provide a ranking list, to assess each player's strength at

any given point in time. The BCF (British Chess Federation) grading book is usually published annually in the

month of September. The ELO ratings are published twice a year. Once the list is drawn up it serves many

purposes:

a. Pairings in a Swiss Tournament draw.

b. Selection for a county or a team.

c. Selection for a rated tournament.

d. To award titles.

There are two main rating systems in use at the present time:

First the worldwide known ELO (FIDE) rating system, invented by a Hungarian, Professor J.Elo;

Second, the BCF rating system, which was invented by English Civil servant and grading expert Sir Richard

Clark. These produced different results.

Additionally, Chesterfield Chess Club players, who played or are playing, in the Sheffield Chess League are

also listed in the Yorkshire rating list.

For comparison, the categories can then drawn-up as follows:

Chesterfield Chess Club Members 2008 - 2010:

Title ELO grades BCF & York. Chesterfield Players

Senior Master 2400 plus 225 plus 0

Master (FIDE) 2200 - 2399 200 - 224 1

Expert 2000 - 2199 179 - 199 3

Class 'A' 1800 - 1999 150 - 174 4

Class 'B' 1600 - 1799 125 - 149 4

Class 'C' 1400 - 1599 100 - 124 6

Class 'D' 1200 - 1399 75 - 99 5

Class 'E' Below - 1200 Below - 75 9

To convert from Elo grade to BCF grade subtract 600 and divide by 8.

The rating system is expressed graphically, rather than in a simple algebraic form. The data that is taken

from the graph will be used to convert an obtained percentage score, to indicate the difference in rating

between between the players.

Examples of rating differences are set out in table 1:

Table 1:

Expected Score %: 90 80 70 60 50 40 30 20 10

Rating Point ELO: 366 240 149 72 0 -72 -149 -240 -360

Difference BCF: 46 30 19 9 0 -9 -19 -30 -46

Examples of winning experiences are set out in table 2.

Table 2.

Players rating ELO: 0 50 100 200 300 400

Differences BCF: 0 6 13 25 38 50

Expected scores:

Highest rated player: 0.50 0.57 0.64 0.76 0.85 0.92

Lowest rated player: 0.50 0.43 0.36 0.24 0.15 0.08

Development Coefficient:

The coefficient for each player is set at 45(ELO) points for the first 100 games, 30 fort the next 200 games,

and 20 thereafter. Junior players have 45 irrespective of the number of games.

Calculation of an initial rating:

An unrated player plays in a series of events against 20 players whose average 1750(ELO) and scores 8

wins and 12 losses. Percentage score is 8/20 or 0.40 for which table 1. indicates Performance = 72.

The player is 72 points below the other players therefore his rating is 1678(ELO).

Calculation of a performance rating:

An unrated or provisionally rated player scores 70% in a 5 round Swiss tournament against opponents

whose ratings average 1601(ELO).

The illustration in table 1 is used to given an expected rating point of 149.

Then by adding 149 to the rating average score of 1601, the player's established rating becomes

1750(ELO).

Calculation of an established player's rating:

An established player with a rating of 1778(ELO) plays six games during the year, meeting rated players

as follows:

Opponent Rating Diff' Expectancy Score

A. 1828 -50 0.43 1/2

B. 2178 -400 0.08 0

C. 1678 100 0.64 1

D. 1728 50 0.57 1/2

E. 1978 -200 0.24 1

F. 2078 -300 0.15 0

Total 2.11 3

The player's Coefficient is 45 points.

The player's new rating is therefore: 1778 + 45(3-2.11)= 1818(ELO).

The player has performed above his expectancy and has gained points. (G.P)

are used for; what they mean; and how they are calculated.

The purpose of the rating system in chess is to provide a ranking list, to assess each player's strength at

any given point in time. The BCF (British Chess Federation) grading book is usually published annually in the

month of September. The ELO ratings are published twice a year. Once the list is drawn up it serves many

purposes:

a. Pairings in a Swiss Tournament draw.

b. Selection for a county or a team.

c. Selection for a rated tournament.

d. To award titles.

There are two main rating systems in use at the present time:

First the worldwide known ELO (FIDE) rating system, invented by a Hungarian, Professor J.Elo;

Second, the BCF rating system, which was invented by English Civil servant and grading expert Sir Richard

Clark. These produced different results.

Additionally, Chesterfield Chess Club players, who played or are playing, in the Sheffield Chess League are

also listed in the Yorkshire rating list.

For comparison, the categories can then drawn-up as follows:

Chesterfield Chess Club Members 2008 - 2010:

Title ELO grades BCF & York. Chesterfield Players

Senior Master 2400 plus 225 plus 0

Master (FIDE) 2200 - 2399 200 - 224 1

Expert 2000 - 2199 179 - 199 3

Class 'A' 1800 - 1999 150 - 174 4

Class 'B' 1600 - 1799 125 - 149 4

Class 'C' 1400 - 1599 100 - 124 6

Class 'D' 1200 - 1399 75 - 99 5

Class 'E' Below - 1200 Below - 75 9

To convert from Elo grade to BCF grade subtract 600 and divide by 8.

The rating system is expressed graphically, rather than in a simple algebraic form. The data that is taken

from the graph will be used to convert an obtained percentage score, to indicate the difference in rating

between between the players.

Examples of rating differences are set out in table 1:

Table 1:

Expected Score %: 90 80 70 60 50 40 30 20 10

Rating Point ELO: 366 240 149 72 0 -72 -149 -240 -360

Difference BCF: 46 30 19 9 0 -9 -19 -30 -46

Examples of winning experiences are set out in table 2.

Table 2.

Players rating ELO: 0 50 100 200 300 400

Differences BCF: 0 6 13 25 38 50

Expected scores:

Highest rated player: 0.50 0.57 0.64 0.76 0.85 0.92

Lowest rated player: 0.50 0.43 0.36 0.24 0.15 0.08

Development Coefficient:

The coefficient for each player is set at 45(ELO) points for the first 100 games, 30 fort the next 200 games,

and 20 thereafter. Junior players have 45 irrespective of the number of games.

Calculation of an initial rating:

An unrated player plays in a series of events against 20 players whose average 1750(ELO) and scores 8

wins and 12 losses. Percentage score is 8/20 or 0.40 for which table 1. indicates Performance = 72.

The player is 72 points below the other players therefore his rating is 1678(ELO).

Calculation of a performance rating:

An unrated or provisionally rated player scores 70% in a 5 round Swiss tournament against opponents

whose ratings average 1601(ELO).

The illustration in table 1 is used to given an expected rating point of 149.

Then by adding 149 to the rating average score of 1601, the player's established rating becomes

1750(ELO).

Calculation of an established player's rating:

An established player with a rating of 1778(ELO) plays six games during the year, meeting rated players

as follows:

Opponent Rating Diff' Expectancy Score

A. 1828 -50 0.43 1/2

B. 2178 -400 0.08 0

C. 1678 100 0.64 1

D. 1728 50 0.57 1/2

E. 1978 -200 0.24 1

F. 2078 -300 0.15 0

Total 2.11 3

The player's Coefficient is 45 points.

The player's new rating is therefore: 1778 + 45(3-2.11)= 1818(ELO).

The player has performed above his expectancy and has gained points. (G.P)