Crew training and handicap

At a sailors form it was discussed about how to bring on trainees of all ages and my strong belief is that after doing your initial training a season crewing for someone experienced may install that feeling of confidence, become part of something at the club and in general benefit the person and hopefully encourage them to stay with it.
So how do you get helms to accept taking on a novice for a crew?
My thought was to run a handicap preference system so say in a 400 at the start of sailing with a new crew the team would get 100 points prference and this would reduce month on month by 20 points so after 5 months it would be scratch.
If a crew then packed it in after a couple of months and the helm had to go back and start again it would revert to 100.
In slower and faster boats the numbers would need to be tweaked based on class speed and crew input.

I got to 100 for the 400 as I sail a phantom and start with the 400 fleet at the club and I can hold and sometimes beat the slower 400's on the water so the difference would need to be greater than the py difference between Phantom at 995 and 400 at 948?
What do you think of the idea and the numbers?

maybe we need a simple boat - no kite, no trapeze, low string count and about 14.5 foot long.  Something with nice clean lines but still 'looks like a boat' that can work equally well on the sea and on restricted inland waters. 

I was using the 400 as an example. It would be whatever was sailed at your club and has the most experienced helms.
Having a good racing helm in the back of the boat makes a huge difference in the whole expeirience for the crew. The boat is flat when you try any manoveres and can can a spare hand when needed. Sailing with someone who is willing but not very good could well scare people off the sport.

Its definately the way to go, but like RS400atC I dont like the idea of complex maths.

To be honest its how most of us who have been sailing for the last 30yrs or more started, but seems to currently be out of favour. If Im sailing my Grad and my daughter isnt around I'll happily take anyone out regardless of experience. I did it a few times this year and even won a couple of races with complete novices in the boat.

It feels good to get people out on the water and enjoying races rather than seeing them pottering around in toppers too scared to go anywhere near the racecourse.