LineThe definition
A unit is a fixed slice of your bankroll — most commonly 1% to 2% — that you use to size every bet. If your bankroll is $1,000 and your unit is 1%, one unit is $10. A "2-unit play" is $20. That's the whole concept, and it does more work than anything else in betting.
Units exist because dollars lie. If someone tells you they won $5,000 last month, you know nothing — they might have wagered $200,000 to do it. If they tell you they're up 14 units on 300 plays, you know almost everything: their volume, their return on risk, and whether the result could plausibly be skill instead of variance. Units are the common denominator that makes any two bettors — or any bettor and any tout — comparable.
How big should a unit be?
Smaller than feels right. The standard advice is 1–2% of bankroll, and the reasoning is survival math: even genuinely good bettors — the ones hitting 55% against the spread, which is elite — routinely run 0-for-8 stretches. At 1% units, an eight-bet losing streak costs 8% of the roll and you keep playing your game. At 10% units, the same ordinary streak costs most of the bankroll, and the bets that follow get made scared, big, or both.
A useful way to set the number: pick the losing streak that would genuinely happen to a decent bettor in a bad month — call it ten straight losses — and choose a unit size where surviving it feels boring rather than painful. For most people, that lands at 1%.
Flat staking vs. variable staking
Flat staking means every play gets the same one unit regardless of confidence. It's the default recommendation for a simple reason: bettors are terrible at knowing which of their own picks are the good ones. Decades of tracked records show most people's "max confidence" plays perform about the same as their standard ones — they just lose more money on them.
Variable staking (1u standard, 2u strong, 0.5u lean) is defensible once you have a few hundred graded plays proving your confidence tiers actually mean something. Until the sample exists, tiering is astrology with extra steps. LineCuller keeps it nearly flat: best bets are 1 unit, and lotto parlays are hard-capped at 0.25 units because their whole job is entertainment, not growth.
Units are a lie detector
Here's the practical payoff: units make dishonest records almost impossible to hide. A tout bragging about "won $12,400 this week!" without unit sizing is telling you the record can't survive being normalized. Watch for the classic move — standard plays quietly graded at 1 unit while the losses turn out, retroactively, to have been "half-unit leans," and the wins were all "5-unit MAX BOMBS." If the unit sizing wasn't posted before the game started, it isn't a record; it's marketing. We wrote a full field guide to this in how to read a betting record.
The mindset shift
Once you think in units, betting stops being a series of dollar decisions and becomes one long portfolio decision — closer to position sizing in trading than to gambling folklore. The question is never "how much do I want to win tonight?" It's "what fraction of my capital does this edge, if it even exists, deserve?" That reframe is worth more than any pick anyone will ever sell you.