It was meant to be $1 per horse TO. 7 horse race, $7 return. CP's right, you have to be getting overlays per horse, not necessarily beating Betfair SP, IMO.

As for data download, I downloaded each file to excel 2010. Then filtered out Place bets, missing data etc. then did a multiple copy (52 workbooks) to a single excel workbook. I think excel 2010 is good for 1 mill rows. I was surprised how well it went. I used excel forums to solve all my filtering questions and never had to resort to VBA, phew! I use the files from Betfair.com.au, as the UK files are huge. Still lots of missing info though, but only usually remote trotting tracks in NZ.

I don't agree with unlimited funds though. Just a conservative 1% of Bank, whatever size, and NO Martingale! Just bet multiple overlays in every race if found, to get that turnover happening. The overlay % will pull you through. Run of Outs is your next mental hurdle to overcome.