Exactly becareful.

That's why many "professional" punters go broke backing favourites.

You must have a system that throws up occasional good priced winners and a good average dividend.

It's all mathematics -
Strike rate to dividend ratio.

You can have a strike rate of 1 winner in a thousand but the dividend is 2000/1, or you can have a strike rate of 1 winner in two and the dividend is 2/1....same thing.
The second strike rate just means more consistent winners but same profit at level stakes.

__________________
Treat your selection and staking methods not with optimism, nor with pessimism, but with realism.