You don't know your reward are you telling me you know where the market goes next?
The only thing you truly control is your risk. If what your'e doing is setting a stop and an arbitrary take profit of more than twice the stop (it has to be to take care of dealing costs) then long term it will fail. If you are bringing discretion to the table with entries then you are not trading mechanically.
Yes I am talking about having a fixed target compared to your stop....you can have statistical knowledge of where the market willl go next...but you miss the point the by having a positve reward to risk ratio depending on the ratio size you can have up to 60% losses and still break even. So long term your system breakseven. Uless obviously it drops below that level but you would have to go through a period of breakeven before it goto that stage.