Stake explained

The stake is what you put at risk. Decimal odds include it in the quoted return (odds × stake = total back, including the stake); fractional odds quote profit relative to it. Every sensible staking conversation is about sizing this number, not about picking winners.

Two disciplines cover most of what matters: size stakes as a small fixed fraction of a dedicated bankroll, and never resize upward to chase a loss. The mathematics of ruin is driven almost entirely by stake sizing, not by pick quality.