Casino math without the fake certainty.
Probability describes what tends to happen across repeated trials. It does not promise what happens next. That single distinction protects readers from a remarkable amount of bad gambling advice.
House edge
The casino’s expected share of initial wagers under specified rules.
Expected value
A common unit for comparing payouts, probabilities and long-run cost.
Baccarat case study
See how similar-looking bets produce very different expected costs.
Three numbers people often confuse
Probability
How often an outcome should occur across a defined model.
Payout
What the operator returns when that outcome occurs.
Expected value
The probability-weighted average result across all defined outcomes.
Why “I won last night” proves almost nothing about the edge
Variance dominates small samples. A negative-expectation game can produce many winning sessions; a sound poker decision can lose the hand. The long-run model and the short-run result answer different questions.