This idea is worth continuing
exploration. Perhaps when you sign your horse up, you would indicate the
year you intend to do your first 100. That way everyone can personalize
their own training program. As was previously noted, some may take 3 years
but some may want to do their first 100 after 4 years. So you would put
your money into the futurity pot for your chosen year. I'll put in for my
3 year old when he "comes of age" !