pearcy, Go4it,

I have lots of systems I have developed over time and some work and some dont.

The best advice I can give is ...

Pick something that is deemed as bad by the general public. A classic example is outide barriers, or low weight , or excessive weight, or an apprentice jockey, more than 5 lengths last start, etc.

This will get you the odds. Then work out ways to make the strike rate better. It is the only tried and tested method I have come up with for developing profitable systems.

Good Luck.