I can only test back to August but here :

There were 60272 horse form lines in the database at this point in time. We update when we get time.
There were 222 selections for the System
There were 211 races for the System
There were 43 Winners for the System for a strike rate of 19.37%
There were $179.16 returned for WIN (after 5% commission) which means a Profit or loss of $-42.84 or a percentage profit/loss of -19.3%

Test Another System

The Rules used were : lastStart = 1 and age >= 3 and age <=5 and daysLastStart >= 1 and daysLastStart <=7

Given this uses betfair prices it shows a slightly better result then the -25% from the other programs.