Expected value
Definition · Level 13 · Interview mechanics
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The probability-weighted average of the outcomes: add up each payoff times its probability. It is what you would win per game on average over thousands of games.
Example
Win €6 on a six, lose €1 otherwise: 1/6 × 6 − 5/6 × 1 ≈ +€0.17 a game.
Where Tradecraft teaches it
Level 13 · Interview mechanics, in the lesson “Expected value, waiting times and games”: Expected value as the average win per game, linearity, waiting-time states and games solved backwards.
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