Fair Game Interview Questions
Fair game interview prep for zero expected value games, fair prices, martingale intuition, and risk-neutral interpretation mistakes.
Candidates preparing for fair coin, dice, and trading-game valuation prompts.
Fair means zero expected gain
A fair game has expected net payoff equal to zero for the participant under the model assumptions.
Fair price
If a random payoff has expected value 10, charging 10 to enter makes the net expected value zero in a simple fair-pricing setup.
Concrete example
A game pays 2 dollars on heads and 0 on tails for a fair coin. The expected payoff is 1 dollar, so a 1 dollar entry fee makes it fair.
Fair is not attractive
A fair game is not automatically desirable. Variance, bankroll, utility, and constraints can still matter.
Martingale connection
Fair-game intuition is related to martingale reasoning: given current information, the expected future value has no favorable drift.
Common mistakes
Candidates often call a positive gross payoff fair without subtracting the entry cost. Fairness is about net expected value.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.