you've got it all wrong - that's funny!

winning and losing goes in streaks, therefore you would be better off increasing your bets after a win and decreasing after a loss if you feel a streak is going to happen. Otherwise bet level stakes.

One punter on racingandsports site reckons you should bet more on longer priced horses, just go each-way. The theory is if your going to risk more capital, then the reward should be greater. Example only, 4/1 horse maybe bet $10, 10/1 horse bet $20 e/w. 20/1 horse bet $30 e/w. He does point out that you should be very confident of a horses winning chances (as confident about the 20/1 hope as a 4/1 chance) though to bet.
There is merit in the madness. One 20/1 winner would pay for a lot of 4/1 losers using this staking plan.