Guides · Bankroll

Sports Betting Bankroll Management

Unit sizing, flat betting vs the Kelly Criterion, and how to track ROI properly — the boring discipline that separates long-term winners from everyone else.

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Bankroll · ROI

The 30-second answer

Decide a bankroll you can afford to lose. Pick a unit size — usually 1-2% of that bankroll — and bet that on a normal play. Log every bet. Recompute your unit every month or after a ±25% bankroll swing. That's it. The strategy beats the picks.

Step 1 — Define your bankroll

Your bankroll is money set aside only for betting. It is not your rent, not your emergency fund, and not money you'd be upset to lose. Once it's set, stop topping it up impulsively — re-evaluating the size quarterly is healthy; reloading mid-tilt is not.

Step 2 — Pick a unit size

Conservative1% of bankroll
Standard2% of bankroll
Aggressive3% of bankroll

A $2,000 bankroll at 2% = a $40 unit. Most plays risk 1 unit; high-confidence plays can risk 2 units; nothing should ever risk more than ~3 units in a single bet.

Flat betting vs the Kelly Criterion

Flat betting

Same stake on every play (or every play in a tier). Boring, predictable, and what almost every long-term profitable bettor actually does. Removes emotion entirely.

Kelly Criterion

f = (bp − q) / b

Where b = decimal odds − 1, p = your win probability, q = 1 − p. Maximizes long-run growth, but punishes any overestimate of p. Use a ¼ or ½ Kelly in practice.

Worked example — odds +120, model says 50%
b = 1.20 · p = 0.50 · q = 0.50
f = (1.20 × 0.50 − 0.50) / 1.20 = 0.083 → 8.3% full Kelly
¼ Kelly → 2.1% of bankroll

Tracking ROI in sports betting

ROI is the only metric that matters. Win rate alone is meaningless — a 60% win rate at -200 is a losing strategy. The formula:

ROI = (Net profit ÷ Total staked) × 100
  • 0-3% ROI — break-even / barely beating juice.
  • 3-7% ROI — solid long-term edge.
  • 7-15% ROI — elite, usually over a small sample.
  • 15%+ ROI over 500+ bets — extremely rare; double-check the math.

Always slice ROI by sport, market, and bet type. You might be +9% ROI on NBA totals and −4% on parlays — the aggregate number hides both.

How the Saint Picks Performance Tracker handles this

You don't have to maintain a spreadsheet. Saint Picks ships with a bankroll tracker that does the work:

Live bankroll curve

Every settled bet updates your bankroll graph so you can see streaks and drawdowns at a glance.

ROI by market

Auto-tagged splits by sport, market, and bet type so you stop betting categories where you lose money.

Unit recommendations

Every premium pick ships with a recommended bankroll percentage so unit sizing is one less decision.

Common bankroll mistakes

  • Chasing losses. Doubling your unit after a bad night turns a 20% drawdown into a 60% one fast.
  • Resizing your unit every day. Recompute monthly or after ±25% bankroll swings — not after every win.
  • Going full Kelly. Your edge estimate is almost certainly inflated. Use ¼ Kelly and your variance will halve.
  • Tracking only win rate. Always look at ROI; a 60% win rate at -200 is still negative EV.
  • No log. If it isn't tracked, it didn't happen — you can't optimize what you don't measure.

FAQ

What size bankroll should I start with?

Whatever you can comfortably lose. The exact number doesn't matter — the discipline of unit-based sizing on top of it does. Many bettors start with 50-100 units worth of capital.

How often should I update my unit size?

Monthly, or after a ±25% swing in bankroll. Resizing too often turns variance into emotional decisions.

Is parlay betting bad for bankroll management?

Parlays have higher variance and worse expected value per leg. Treat them as entertainment stakes (≤ 0.5 units), not core bankroll plays.

For entertainment and analytical purposes only. 18+. Bet responsibly.