Shoto,
To be honest I don't have a set strategy for every race, although the principle is the same. I read the market and make decisions on the best approach and may have three different strategies in the one race.
I approach a race with an odds on favourite quite differently to an open 4/1 the field race.
As an example: In a trot race tonight I assessed (better word than "knew") that the long odds on favourite would firm in the market and the longer horses would blow in the market, so simply backed the odds on pop and layed all the longies at shorter prices than they'd end up on the tote. As they were scoring up, I was able to lay the odds on horse @$1.15 and had backed it @$1.51. I also bet back on the longshots on the tote which were "free" bets.
If the shorty won I would have made a small profit
If the shorty lost I would have been square if a longshot didn't salute.
If a longshot saluted I would have made a huge profit @ no risk.
The best scenario was a very nice profit
The worst breaking even!
As it stood I won a small amount for the race as the odds on favourite held off challengers...one of those challengers was one of the longshots
.
But multiply betting like this over 100 races and you have to end up in front as long as the prices are right, although of course it doesn't always go exactly to plan and this is only one strategy in the armoury.
Someone once told me I'd go broke laying every favourite on Betfair (Racing, Pacing, Australia, U.K, South Africa, United Arab Emirates etc).
But I'm doing it, and winning better percentages than I thought.
The only thing I avoid is the USA.