A good system could be to back high class jump horses who are tailed off on their first run, as those pesky jump trainers always have them coming on 20 stone for the run a la Bobs Worth and Cue Card this season.
Sadly not. The system relies on a minimum payout on the tote place and a reasonable deduction of 5-10% like you get in the usa, rather than the 18% deduction you get here on the toteplace.