## The Single-Point Prediction Problem
Most bettors think in single-point predictions: "Arsenal will score 2 goals." "The match will end 1-0." These point predictions ignore the crucial fact that sports outcomes are probabilistic — there is a distribution of possible outcomes, not a single certain outcome.
## Switching to Distribution Thinking
Instead of "Arsenal will score 2 goals," think:
- P(0 goals) = 8%
- P(1 goal) = 22%
- P(2 goals) = 27%
- P(3 goals) = 23%
- P(4+ goals) = 20%
This distribution (derived from a Poisson model with Arsenal's expected goals rate) is far more useful than a single point prediction. It allows you to calculate the probability of any total-goals outcome, any over/under line, and any scoreline.
## The Confidence Interval Discipline
For any prediction, always estimate a range rather than a point:
"I estimate Arsenal win probability at 52%, with a 90% confidence interval of 43–61%."
The width of the confidence interval reflects genuine uncertainty. A narrow interval means you have high-quality information. A wide interval means the outcome is genuinely uncertain — which should affect stake size.
## Expected Value from a Distribution
The full over/under model derives expected value from the entire probability distribution:
EV(Over 2.5 at 1.91) = P(over 2.5) × 0.91 + P(under 2.5) × (−1)
= (sum of P(3 goals) + P(4 goals) + ...) × 0.91 − (sum of P(0,1,2 goals)) × 1
Distribution thinking enables exact EV calculations rather than rough estimates.
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