Dirk Gently.
Consider your 30 races.
Let them be the next 30 races to be run.
So that's 4 meetings with about 7.5 races each.
Of them 8 are maidens,8 lower class events and maybe 4 are not worth considering for various reasons.
We now have 10 races left to bet on with more time to study each race more deeply and 20 more units to invest.So now we can box 3 in the Quinella.
Better still take our 2 best in each race and invest 2 units,and 1 unit with our third selection into our 2 best.
Quite often our 3rd best selection is at large odds and can give us a large collect.