No I wouldn't. The average SR for odds-on horses winning is around 50%. Runs of in's or outs for odds-on horses doesn't make any difference. Good for arbitrage betting maybe, but hardly a good profit making target by guessing if odds-on runners are overs or unders. LOL. LOL.

Looking at odds of say 2.70 [Bartholomew's bet odds for his $100k], when
converted to book % we are talking tiny %. To be able to say 2% chance of winning is about right but 3% is overs, is absurd. There will never be enough info available about a field of horses, or how a race will pan out in the running to calculate such tiny chance differences. It's an educated guess at best surely.

I think when Bartholomew says a horse is unders or overs he's talking about what odds he can bet at compared to what odds he can lay for. By his own admission in the interview he's no form student, but investor [an abridger]. Great if you have enough capital to make the small % profits meaningful. He said he went broke 50 times as a semi-pro punter until he gave it up and went into backing and laying when he was a small time bookmaker for a short period.

If their is a good profit potential through his arbitrage betting style, he can then calculate a horse's 'overs' or vis-a-vis 'unders' very accurately, but he's using those terms loosely for convenience, not in their accepted meaning to most punters.

Cheers.