Unit
A unit is a standardized betting amount used to express bet sizes and track performance independently of dollar values. Most serious bettors size their bets in units rather than fixed dollar amounts, with a single unit typically representing 1-2% of their total bankroll.
How It Works
If a bettor’s total bankroll is $5,000 and they use a 1% unit:
- 1 unit = $50
- 0.5 units = $25 (smaller stake on lower-conviction bets)
- 2 units = $100 (larger stake on high-conviction bets)
- 5 units = $250 (large stake — typically reserved for very high conviction or arbitrage)
If the bankroll grows to $7,000, the unit grows proportionally to $70. If it shrinks to $3,000, the unit shrinks to $30.
Why It Matters
Using units rather than fixed dollar amounts has several advantages:
Bankroll-proportional risk. A 1-unit bet is always the same percentage of the bankroll. As the bankroll grows or shrinks, bet sizes adjust automatically. This is foundational bankroll management — never betting too much when on a downswing, and not under-betting when on an upswing.
Performance tracking is comparable. “I’m up 50 units this year” is a clean performance metric. “I’m up $5,000” is dependent on bet sizes and bankroll, which can be misleading.
Standardized communication. Tipsters, content creators, and bettor communities use units to communicate about plays without revealing personal bankroll size. “5-unit play” is meaningful regardless of the recipient’s actual bankroll.
Unit-based language survives bankroll changes. A bettor’s record over multiple years remains comparable even as their bankroll grows. “I went +70 units last year” is consistent across bankroll changes; “I made $7,000” depends on which year’s bankroll you’re using.
Common Unit Sizing Approaches
Flat unit: Every bet is exactly 1 unit. Simple, low-variance. Commonly recommended for beginners.
Confidence-based units: Bet 0.5-3 units depending on perceived edge. Higher conviction → larger stake. Most common among recreational bettors who believe in their handicapping. Easy to over-bet “favorite” plays.
Edge-based (fractional Kelly): Bet sizes scale with the calculated edge percentage. A 5% edge gets a smaller bet than a 10% edge. Mathematically rigorous but requires accurate edge estimates.
Full Kelly Criterion: Bet sizes optimized to maximize log-bankroll growth. Aggressive — most bettors use fractional Kelly (e.g., quarter-Kelly) due to estimation error and emotional tolerance.
For most serious +EV bettors, the typical approach is something like:
- Flat 1-unit bets on ordinary +EV plays
- 2-3 units on high-conviction plays
- Quarter-Kelly sizing for systematic strategies with calculable edges
- 1-unit cap on individual prop bets (where edge estimates are less reliable)
Common Pitfalls
Increasing unit size during winning streaks. “I’m running hot, let me bet 2 units now.” This often coincides with the streak ending — a classic variance trap.
Decreasing unit size during losing streaks. “Let me cut down to 0.5 units to ride this out.” This protects the bankroll but also reduces the recovery rate when the streak reverses.
Inconsistent unit definition. Changing what “1 unit” means month to month makes performance tracking meaningless. Define your unit clearly and stick with it across at least a season.
Treating units as small. A “10-unit play” sounds small. If your unit is 1% of bankroll, a 10-unit play is 10% of bankroll on a single bet — extremely aggressive sizing. Be precise about what units mean in dollar terms.
For more on bet sizing approaches, see +EV Betting Explained.