This is the core of Warren Buffett's entire approach to investing.
Buffett invests only in what he understands, where he has conscious and unconscious competence.
But he goes further: his method of avoiding risk is built into his investment criteria. He will only invest when he can buy at a price significantly below his estimate of the business's value (the intrinsic value). He calls this his "Margin of Safety."
Following this approach, almost all the work is done BEFORE an investment is made. (As Buffett puts it: "You make your profit when you buy.")
This process of selection results in what Buffett calls "high probability events": investments that approach (if not exceed) Treasury bills in their certainty of return.