What variance does to a good bet

Suppose a method is genuinely good: it finds bets at 2.00 that win 53% of the time. That is a 6% edge, which is large by any honest standard. It will still lose 47 of every 100 bets, and that is where almost everybody's intuition breaks.

#What a normal bad run looks like

At 53%, a run of eight consecutive losses has about a 1.6% chance of happening on any given bet. Over a year of 500 bets, the chance of seeing at least one such run somewhere in the year is very high indeed. It is not a warning sign. It is the weather.

The same arithmetic says a run of ten wins is also coming, and it is no more meaningful. Both are what a 53% coin does when you flip it five hundred times.

#Why this changes what you should measure

If good weeks and bad weeks are both routine, then reading either as evidence is reading noise. The method has not changed; the sample has.

This is the reason this product publishes the closing line rather than the profit as its primary scoreboard. Whether a bet won is one bit of information arriving weeks later. Whether it was taken at a better price than the market settled on is measurable immediately, on every bet, including the ones that lost.

#What it does to staking

Variance is also the reason staking is not a detail. A method with a real edge and stakes that are too large for the bankroll it is drawn from can still run out of money before the edge arrives, and running out of money is final in a way that a bad month is not.

#What this does not tell you

None of this establishes that any particular method has an edge. Variance cuts in both directions: it hides real edges under bad runs, and it manufactures fake ones out of good runs. A year of profit is not proof, and neither is a year of loss.