When trying to explain the GAP scoring system to pilots, the
developers of the scoring system and others have tried to stick to pretty
pictures, because frankly the equations which our computers use to draw these
pictures can get pretty ugly and without the pictures they don't make much
sense. There is no real reason why one equation would be chosen over another or
why one set of coefficients is the right ones, other than the fact that the
pictures that they draw appear to be reasonable.

You'll find an excellent discussion of the GAP scoring system
here along with its implementation in the scoring program FS
here. But there is still this
idea that the GAP system is somehow encouraging you to fly out in front. This
document states:

The GAP scoring system rewards the pilot who makes his own
decisions and stays in front of the others. Waiting on takeoff for the other
pilots to fly, then following to be safer and faster, is a less valuable tactic in
terms of this scoring. With previous scoring systems your best tactic to recover
points over your opponent was to start a few minutes after him, then catch him.
His best tactic was to wait for you and fly with you. Everybody was always
waiting on takeoff because everyone was following the same tactic! With this
scoring system a good tactic to catch up points on your opponents is to start
early and fly fast. This way you force your opponents to take the risk of being
an early bird with you, or wait for more pilots to be in the air for safer
(scoring wise) flying.

As I have pointed out in the last article, I would take that
statement with a large grain of salt. Flying fast using pilots out in front who
took an earlier start time and getting to goal is almost
always better than going early and trying to grab the points for being out in
front and getting to goal early.

So where do leading points come front? Let's look back at a chart from the last
article:

Case 1a.

If you formed a triangle with the blue line as a hypotenuse, the x-axis as one
leg and the y-axis on the right side as another you would enclose the area under
the first pilot's flight curve (actually a straight line). As here:

You can in a similar
manner find the area under the second pilot's curve (which includes the little
rectangular area bounded by the Y-axis from 0 to 10 minutes and and the x-axis
from 0 to 100 km). See here:

Because the first pilot was faster than the second pilot you can see that his
area under his curve is less than the area under the curve of the second pilot.
It is the relationship between these areas that it used to define the "leading
factor" which is multiplied by the available "near the front" points to see how
many "leading" points the pilot gets. Now the pilot with the smallest area (whether they
make goal or not) gets 100% of these points. The pilots with bigger areas get a
smaller percentage of them.

The leading coefficient for a given pilot is defined as the area under his
flight curve in seconds and meters divided by 1800 and by the task length in
meters.
The equation that uses these leading coefficients to find the "appropriate"
multiplier is found in the document linked to above on page fifteen (out of eighteen).
Also:

Of
course, not all flights are as idealized as these flights so the curves can get
pretty messy and we have to come up with a bunch of additional rules to handle
them. In fact the pictures that display the curves can lead us astray when it
comes time to actually figuring out how this works. For example:

And this one:

I hope that I've given you a taste of the idea that perhaps "leading" points are
maybe not what you thought they were. They certainly aren't easy to understand
and they certainly aren't leading.

The leading coefficient calculated for the first pilot, a pilot who flies 100 km
to goal in two hours (a pretty darn fast pilot) is equal to two (notice how in
this idealized case it is just the time it took the pilot to get to goal). You
can see the relationship between slower or later pilots with their larger
leading coefficients by looking at this chart:

You should be able to find three of the previous idealized cases on this blue
line.

As the other pilots' leading coefficients increase relative to the first
pilot's, their multiplier times the available leading points decreases. You will
find additional charts that map out this relationship for different minimum
leading coefficients
here. Go here
if that direct link doesn't work. Check out Appendix C, page C-8. This Appendix
is an excellent resource for understanding GAP and the equations that are used
for scoring.

I'll discuss leading points and compare them with departure points more later,
but I'll first take a break and look at some GAP parameters.