Quick Tools · All Sports
Unit Sizing & Bankroll
How much to actually bet. The edge means nothing if the stake blows up your roll on a normal losing streak — sizing is the discipline that keeps you in the game.
1 · Flat unit sizing
A “unit” is one standard bet. Most bettors set 1 unit = 1–2% of the roll and bet the same size every play.
Conservative · 1% / unit$10
Standard · 2% / unit$20
Aggressive · 3% / unit$30
Keep even your biggest single play at or under ~3%. Past that, a routine 5–6 loss run does real damage.
2 · Fractional Kelly (edge-based)
Break-even at these odds52.4%
Your edge+2.6%
Full Kelly (too volatile)—
Half Kelly—
Quarter Kelly (recommended)—
Kelly assumes your win% is right. It rarely is, so pros bet a fraction. Negative edge → Kelly says $0. Don’t force it.
The rules that actually protect the bankroll
1
Flat-bet by default. Same size every play (1–2%). Varying stakes by “confidence” feels smart and quietly wrecks records — your confidence isn’t calibrated enough to trust.
2
Never chase. Increasing size after losses to “get it back” is the #1 way bankrolls die. The math doesn’t know you’re owed.
3
Expect long losing runs. Even a real +EV bettor hits 5, 6, 7-loss streaks routinely. Sizing that survives variance is the whole point — ruin is permanent, a drawdown isn’t.
4
Parlays are entertainment stakes. Compounding vig means smaller units on parlays than on your straight plays, not bigger.
5
Re-base occasionally, not every day. Recompute your unit off the new bankroll weekly/monthly, not after every win or loss.
The honest bottom line: we don’t tell you what to bet here — that’s the boards. This is how much, and the answer for almost everyone is “less, and the same amount every time.” A disciplined 1–2% flat stake (or quarter-Kelly on a real, measured edge) is what turns a good read into a bankroll that’s still here next season. Bet what you can afford to lose. 21+