You're right Maurice, it's a tough one, a judgement call. How confident are you in the prices you have?

I remember a chap in the West who had a pricing service, and he would put up his working sheet on his website the Monday after the races. He axiom was to never accept unders no matter what, and his worksheet showed he never budged from that. It was fractional odds then, but as an example, if he rated something 9/4 he wouldn't touch it at 2/1. So he'd then stand it out in Trifectas, multiples etc. because better value would be had in those pools. But if he got 3/1 he'd have a decent win bet on it.