create custom formula

pevenden No worries. The functions I used in the those files will only work with MS365. The main formula that can still be used in Office 2019 for calculating points is:

=(p*(1-((50*a+4800)/98))+((a*(50*a+4800))/98)-1)/(a-1)

...where p is the Position, a is the Attendance, and the Fleet Factor has been omitted.

I've attached another workbook (v3) that should work with Office 2019. In this version, I used Excel Table formatting, with calculated columns for Attendance and Points. The formula used to calculate Attendance is:

=COUNTIF([Race No.], [@[Race No.]])

And the formula used to calculate Points is:

=([@Position]*(1-((50*[@Attendance]+4800)/98))+(([@Attendance]*(50*[@Attendance]+4800))/98)-1)/([@Attendance]-1)

Note: I've excluded the IFERROR function here, as you have stated the minimum number of riders in any given race is 3, so the above formula will return the #DIV/0! error when only 1 rider has been entered in the table for a given race.

Add new data to the bottom of the table by inputting values in the Row No., Position and Jockey columns. Data Validation was used in the Jockey column to select from a list. The source for the pick-list is the Jockey column from the Season Standings table.. adding new Jockey names to this table will make them appear in the pick-list.

After inputting new data, sort the Season Standings table by the Total Points column from largest to smallest to refresh the standings.

Calculate Points and Standings