Risk does equal reward. However, based on experience, I have adapted the concept to have a better success rate.

High Risk - Uncertain outcome with uncertain results. Little to no supporting evidence to directly correlate the decision to results. Some data may support, but a lot seems to be "feeling." Or, the data is present but not properly examined with the hypothesis not clearly formed.

Low Risk - Outcome has a probable direction based on supporting evidence to correlate decision to results

Calculated (Educated) Risk - Evidence to sustain a greater probable outcome but still uncertain results. Vague evidence either by deductive or inductive reasoning correlating  decision to results. This is where "PATIENCE AND PERSEVERANCE" come in. The more time you have to dedicate research and variability in the process or supporting data - the less likely the risk is. In addition, with the data to support the calculations the experiment could be retried manipulating circumstances based on the trial(s).