(Remember Race 5 will be worth double points)

Points are calculated using the following formula:
points = 25*N^(0.30103)[(N+1-p)/N]^(2.0107)
where N is the field size, p is the placing.

OK, so what does this formula mean? Here is Dan Connelly's explanation:

-------

The following is my best stab at an analytic approach, but of course there are infinite possibilies, so this is just an example.

One reasonable constraint is the points progress smoothly zero last to first -- no big jump at last place. This involves a dependence on (N+1-p)/N, where p is the place (1, 2, 3...) and N is the total field size.

Another principle is that placings near the top are worth more than placings near the bottom -- sprinting for 30th place is less important than the sprint for second. Thus, one can raise the (N+1-p)/N to some superunity power. There are other approaches one could take, like modified exponential, but power-law is simple. It seems to me calling first 8 times better than the median is fair, so I'd stick "3" ( 2^3 = 8) here.

This leaves the issue of how the points for the win should scale with the field size. A simple approach is to use field size to some positive subunity power. The test question here is "how much must the field size increase to make the win worth 1% more?" It seems to me 2% is a bit low, but 4% is too high, so I'd take 3%. This makes the power (1/3). This means winning in a field of 5 is like finishing fractionally something like 20% down in a field of 40, with a win in the larger field worth double. This seems about right to me, but then it's all opinion.

All that remains is some constant factor to put the points in a good range. 25 seems to work.

So the formula I'd use is :
points = 25*N^(1/3)[(N+1-p)/N]^3
where N is the field size, p is the placing

This seems complicated, and it is. Trying to calculate this when riding will result in the loss of several places, or more likely, riding into a tree or barrier :). But with a spreadsheet, this shouldn't be a huge issue.

---------

David Crum modified the super- and sub-unity powers a bit to produce slightly different results, but Dan's formula is still intact.

Here is the entire table of points out to 100 places.
Use this table to figure out how many points are available for a given field size.

If you want to go even further, you can read up on the whole points saga at Topica's NCNCA email archive site (look for "Surf City series notes").

Thanks go to Dan Connelly and David Crum for assistance with the formula.

Race 4 Main Page