What 'risk' and 'to win' mean, and why they differ

'Risk' is the stake — the money that leaves your balance. 'To win' is the profit if the bet lands, which excludes the stake. The two are equal only at even money. On any favourite you risk more than you win; on any underdog you win more than you risk.

The asymmetry is the price doing its job. A shorter price is the book saying an outcome is more likely, and the only way to express that in money is to demand more risk for the same reward. So the gap between the two figures is not a fee or a quirk of presentation — it is the entire content of the price, written as two numbers instead of one.

Some interfaces let you type into either box: enter 100 in the risk field and the win field fills itself, or enter 100 in the win field and the risk field fills instead. On a favourite these produce different bets, and the one that fills automatically is easy not to notice.

Which is where it goes wrong. Staking 'to win 100' habitually means risking a different amount on every bet, which quietly makes stake size a function of price. Two bets sized identically in the win column can differ by a factor of four in money at risk, and the money at risk is what a losing run actually takes.

What to do with it. Decide whether you size by risk or by win, and use the same one every time. Sizing by risk is the simpler discipline, because the amount at stake is then the number you chose.