Variance
The random short-term swing around your true win rate. The reason +EV bettors still have losing weeks.
Variance is the natural noise around any betting record. A 55%-true bettor will still have stretches at 40% and 70% over small samples; that’s variance, not skill change.
Why it matters:
- Even +EV bettors lose 10+ in a row sometimes
- Flat-betting reduces the bankroll damage when variance turns negative
- Chasing losses (“doubling up”) amplifies variance damage instead of fighting it
- 1,000+ bets is roughly the sample needed to distinguish skill from noise
Accept variance, don’t fight it. The math wins over enough bets.