What is Variance?
The natural fluctuation of results around expected value — the reason a +EV strategy can still lose for weeks.
Even with a real edge, results swing. A 53% win rate on flat-staked −110 bets can endure 10-bet losing streaks across a 1,000-bet sample. Variance is the difference between a sharp bettor and a recreational one — the sharp prepares for it with bankroll sizing and patience, the recreational rage-bets to break even.
Related terms
The bet-sizing formula that maximises long-run bankroll growth, given an edge and a price.
The dedicated pool of money a bettor uses to place wagers, kept separate from living expenses.
Total profit divided by total stake, the cleanest single number for a sports bettor's performance.
See variance applied to a real slate
NotaSportsGuru runs the math behind every published leg — Parlay of the Day, player props, match lines — with the model’s expected value and edge on every line.