At 06:41 28 January 2016, krasw wrote:
We tried similar idea 5 years ago in GrandPrix-style contest, where
traditional handicapping is not possible. I made simple formula for
calculating turnpoint barrel radius for individual competitors:

R = D / 2N * ( 1 - k/k0 ) + 0,5 * k/k0

R is radius
D task length
N number of turnpoints
k0 handicap of the best glider participating
k your handicap
All distance units kilometers.

It works well enough if angle between legs is large, out-and-return legs
being optimal.

This is where we started but the present system is somewhat more refined.
In the UK we use windicapping which skews towards low handicap gliders as
the wind strength increases.

We also realised that the shortest way around the task is not to go
directly towards the centre of the barrel, nor to the point where the
bisector intersects the barrel circumference.

So we measure the shortest (handicapped or windicapped)path around task for
each barrel size step and compare to the reference task length * handicap
(/handicap in US). This iterative process arrives at the barrel size that
best fits the desired task length for each handicap flying.

Our software will cope with start lines of any length, variable barrels,
acute and oblique turns, checkpoints, angled finish lines and finish
rings.

It then prints a handy briefing document for the pilots.

If you put a task into the calculator then export it into SeeYou you will
see what I mean.

Jim