Outcome Bias
Never judge a decision by it’s outcome
Historian error
We tend to evaluate decisions based on the result rather than on the decision process. This fallacy is also known as the historian error.
Never judge a decision purely by its result, especially when randomness or ‘external factors’ play a role. A bad result does not automatically indicate a bad decision and vice versa. So rather than tearing your hair out about a wrong decision, or applauding yourself for one that may have only coincidentally led to success, remember why you chose what you did. Were your reasons rational and understandable? Then you would do well to stick with that method, even if you didn’t strike lucky last time.