Well I have been dutching 2 horses a race (1 unit on each).

I am doing well because my selection method is sound and based on common sense. I don't intend to dutch any more horses than 2 as the math gets more complicated and it only added a further 10% to my strike rate.

I have increased my strike rate from 25% winning races to approx 45%.

I usually will only alter the bets if one of the horses is below $2.00 ( place an extra unit on it ).

Thanks for all the constructive feedback.