Risk
How Betting Variance Works
The reason a good process can produce a bad month, and a bad process can produce a good one.
What variance is, precisely
Variance measures how much actual results swing around the expected value.
Why sample size changes everything
Over a handful of bets, luck dominates. Over hundreds or thousands, the underlying edge becomes much harder to hide.
The practical takeaway
Judge a betting process by whether decisions were positive-EV at the time, not by a small sample of results.
FAQ
How many bets before results are meaningful?
There's no single number, but hundreds of bets at a consistent edge are usually needed.
Can a losing streak happen even with a real edge?
Yes - the Bankroll Simulator's longest-losing-streak output shows how long a realistic streak can run even for a profitable strategy.