Variance And Drawdowns

A small edge applied to a high-variance activity produces results that look nothing like the edge. Understanding the size of the swings a genuine 55% bettor experiences is what prevents abandoning a working method during a period when nothing has gone wrong.

The Streaks A Winning Bettor Should Expect

At 55%, the probability of losing any given bet is 45%. So five in a row is 0.45 to the fifth power, about 1.8% — which sounds rare until you place 500 bets a season and get roughly nine opportunities per hundred bets for a five-loss run to start.

An eight-bet losing run is a normal feature of a winning season, not evidence of anything. A bettor who reduces stakes, changes approach or stops betting during one is responding to noise.

Why A Month Tells You Nothing

Take a genuine 55% bettor placing 40 bets a month. The standard deviation of their monthly win count is about 3.1 bets, so a one-in-twenty bad month lands near 16 wins from 40 — 40%, which at standard prices is a substantial loss.

Equally, a one-in-twenty good month lands near 28 from 40, or 70%, which any marketing department would describe as elite.

Both months come from the same bettor with the same method. Which means a month of results, in either direction, contains almost no information about ability — and any service advertising a hot month is advertising a coin flip that landed well.

Drawdown Depth And Duration

A drawdown is the fall from a peak to a subsequent trough. For a 55% bettor betting one unit flat, drawdowns of 15 to 25 units over a season are ordinary, and the time spent below a previous peak often exceeds the time spent above it.

That last point is the one people find hardest. A profitable bettor spends the majority of the season not at a new high, because equity curves move in steps with long flat or declining stretches between them. The subjective experience of a winning season is mostly waiting.

Sizing follows directly: a unit small enough that a 25-unit drawdown is 25% of bankroll rather than 100% of it. That is exactly why 1 to 2% is the standard. See bankroll management.

Measuring Skill Faster Than Results Allow

Since win rate converges slowly, serious bettors track leading indicators instead.

Closing line value. Whether you consistently beat the closing number. This converges in tens of bets rather than thousands, and it is the strongest available predictor of long-run profitability. See closing line value.

Calibration. Whether things you rate at 55% happen about 55% of the time across your whole book of bets.

Process compliance. Whether you bet your stated sizes on your stated criteria, which is measurable immediately and is the most common point of failure.

Judging a method on these rather than on last month's units is the difference between managing a betting operation and reacting to one. See sample size.

Frequently Asked Questions