The bottom line is if you dont know why you are really taking the trade then results will never be better than random.
If a trade has over 75% chance of hitting 1:1 r/r you dont want to take it?
If it has over 50% chance of hitting 2:1 you dont want to take it?
If you dont, then you let so much pass you by. The chance of taking a trade where you can get 3:1 r/r and win consistently is very low unless you have enough experience.
Any seasoned trader will tell you this if they are honest.
All that will happen is you will seriously dent your confidence by seeing trades move into your favour and coming back to stop you out.
What you are trying to achieve is not really going to happen if you admit that you believe markets are totally random.
This concept of random entries, making up pie in the sky risk / reward ratios is fictional.
By all means go ahead and try, I pointed out on another thread people will do what they want anyway.
Im not wanting to sound harsh, but you need to focus on other areas first before worrying about r/r.
ie.What is your trading edge?
Once you have established this ,and proven over time you take the right trades at the right time, then worry about r/r. You will be then in a position to pick which trades you want.
Im not a fan of books about probabilities and expectation because only YOU know why you are taking a trade, and therefor why you expect a market to move to where it does.
Good luck in your endeavors.