risk reward is very important but there isnt a magic number where u can say if i have 2:1 i will be successful. Randomly buying with a 20 tick target and 10 tick stop doesnt lead to a great methodology (although may actually make money in the long run, just with horrible drawdowns). It depends on your win rate, ive seen people that risk 2 ticks to make 1 and are very successful, but they have 90% winners. Likewise some people only win 20% of the time but they risk 10 ticks to make 100. Its all about expectancy