If your competition is scored with departure and arrival position
points or with just arrival time points and no one makes goal, then only a total
of 900 points are available. You can configure FS to allow for 1000 points if no
one makes goal, but that is not the default configuration.

If you use 'leading' points you'll not only have 900 points available to give to
the pilot who flew the furthest, but also 17.5 leading points (rounded to
eighteen).

Since 'leading' points are given whether you get to goal or not it was decided
to give them out while they weren't available when they were described as
departure points. Seems a bit arbitrary to me.

The points available for 'leading' in the case of no one making goal are (1000 -
(1 - 0.9)) * 0.125 * 1.4, which is equal to 17.5 points.

Seems to me that there is no good reason why 'leading' points shouldn't be worth
100 points in the case of no one making goal. After all as we've seen in
previous articles someone was 'leading' and even those following get 'leading'
points.

You can find the graph and equations above
here.