The method for calculating the player number check digit in the ABF numbers is calculated in the following way.

Consider the first 6 digits of the number as the number of the player with the 7th digit (the least significant digit) the check digit.

A weighting is applied to each of the digits starting from the left hand side.

The weightings are 7, 6, 5, 4, 3, 2 applying to digits 1 (one) through 6 (six) respectively.

The first digit is multiplied by 7, the second multiplied by 6, the first digit is multiplied by 7, the second multiplied by 6, the multiplied by 3 and sixth multiplied by 2.

The resulting multiplications are summed to give a grand total.

This total is divided by eleven giving a remainder. If the remainder is less than 2 the remainder is used as a check digit else the remainder is subtracted from eleven to give the check digit.

eg. Consider player number 0041475.

The check digit is 5 and is produced in the following way:-

0 x 7 = 0

+0 x 6 = 0

+4 x 5 = 20

+1 x 4 = 4

+4 x 3 = 12

+7 x 2 = 14

sum is 50

Divide 50 by 11 = 4 with remainder 6

Then 11 - 6 = 5 (the check digit)