> The problem is that the 2018 World Cup is not a repeatable event. Neither are most open-market trades...
The 2018 World Cup is not a repeatable event, Elon Musk buying $10M of Tesla shares is not a repeatable event, and Donald Trump winning the 2016 presidential election is not a repeatable event. Therefore, to meaningfully discuss any of these in the context of probabilities and confidence intervals, we must assume that we generalize them to any soccer game, a stock purchase, or an election, and can do this meaningfully by adjusting our priors. It does make the mathematics a lot less pure.
The 2018 World Cup is not a repeatable event, Elon Musk buying $10M of Tesla shares is not a repeatable event, and Donald Trump winning the 2016 presidential election is not a repeatable event. Therefore, to meaningfully discuss any of these in the context of probabilities and confidence intervals, we must assume that we generalize them to any soccer game, a stock purchase, or an election, and can do this meaningfully by adjusting our priors. It does make the mathematics a lot less pure.