Grades This website displays 3 different grades for players, and for event results. The three grade types are: Berkshire Junior, BCF Standard Play, and BCF Rapidplay (BCF = British Chess Federation). On a player detail page, all three grades may be displayed if the player has gained a grade of each type. A results page will only display grades of one type.

BCF Grades BCF Standard Play grades are assigned to players if they have played matches where the time limit is not less than one hour for the initial 30 moves (and, of course, where the match result has been submitted to the BCF for grading purposes). A Standard Play grade can be gained by playing in certain county matches (e.g. under 18 matches), in the adult Berkshire League, or in some tournaments such as the Berks and Bucks Congress. At the start of the 2003-04 season, only 37 Berkshire Juniors had a standard play grade, and many of these would have been based on just a handful of matches.

BCF Rapidplay grades are much more common for Juniors than Standard Play grades. Rapidplay is defined as less than one hour for the initial time period, but no faster than 15 minutes sudden death. Since many Berkshire events are in this class (if only just), we have in the past sent the results off to the BCF for grading.

Berkshire Junior Grades As of September, 2004, the BCF will no longer grade junior events for free. It has been estimated that to carry on submitting results at the same rate as the 2003-04 season would cost us £800! Instead of increasing tournament entry fees to cover BCF grading charges, we have decided to calculate our own grades, and call them "Berkshire Junior Grades". Further, we have decided to adopt the FIDE grade calcuation methods, which are different from the method used for BCF grades.

Grade Calculation The nitty-gritty part. How are tournament results turned in to Berkshire Junior grades? First, all match results for a tournament are entered into the website database (this level of detail also allows the website to display a "crosstab" section on a results page). Then, for each player in the tournament, the following outline method is used to calculate a new Berkshire Junior grade:

• If the player already has a grade, this grade, and the average of their opponents' grades are used to calculate an expected score. Note that results against ungraded players are not included.
• To get the whole system going, if a player does not have a Berkshire Junior grade, but does have a BCF Rapidplay grade, then an initial Berkshire Junior grade is estimated from the BCF grade.
• The difference between a player's expected score, and the actual score obtained against graded opponents is then used to calculate an increase or decrease in the player's grade.
• The player's grade is adjusted accordingly, and their new grade is used in later events.
• For ungraded players, a different computation is performed. An ungraded player has to play at least 3 matches against graded opponents, and score more than zero points in order to gain a Berkshire Junior grade. If these criteria are met, then the average grade of their opponents, and the results of those matches is to calculate their initial grade. Note that results against other ungraded players are not included.

This approach means that:

• Ungraded players have no impact on the grade of graded players (even if the ungraded player wins).
• Grades change continuously throughout the year, after each event for which the above calcuations are performed. Since young players often improve rapidly, this system gives them some immediate feedback on how well they are doing.

The actual formulae used to perform the "calculations" mentioned above are given below. (note: * is used for multiplication, and ** is the exponent (to the power of) symbol):

• For a player with no Berkshire Junior grade, but with a BCF rapidplay grade:
  BG = (RPG * 8) + 600
  where BG = Berkshire Junior grade, and RPG = Rapidplay grade.
• For graded players:
  ES = GM / (1 + 10**( (BJG - AOG) / 400 ) )
  where GM=graded matches; ES = expected score; BJG = Berkshire Junior grade; AOG = average opponent grade;
• Also for graded players:
  GC = BJG + ( K * (AS - ES) )
  where GC = grade change; BJG = Berkshire Junior grade; K = 32 (the progression coefficient); AS = actual score (against graded opponents only); ES = expected score.
• For ungraded players:
  IG = AOG + ( 50 * (AS - GM / 2 )
  where IG = initial grade; AOG = average opponent grade; AS = actual score (against graded opponents only); GM = graded matches.

As an example... Suppose player A, who has a current Berkshire Junior grade of 1000 competes in a tournament and plays 6 matches against opponents with the following grades: 800, 1150, no-grade, 1280, 1190, and 1310. Further suppose that the player scored a total of 3.5 points against the graded opponents. The result against the ungraded player is irrelevant for the purposes of grading calculations.

First calculate AOG (average opponent grade), which gives 1146. Use the ES formula above to calculate expected score, which comes to 1.51 (to 2 decimal places). Next use GC formula to determine the grade change: GC = +49.5. Finally apply the grade change to the current grade to give 1050 (rounded). This is the player's new Berkshire Junior grade, and will be used as the initial value for BJG in any future tournament.