The arithmetic
What is a gambling stake?
A stake is the money you put on a single bet. Everything else in gambling maths is a percentage of it.
Sizing it is the only decision available in most games, and it is the one people make by feel.
Stake, bankroll, turnover
Bankroll is what you are prepared to lose in total. Stake is one bet. Turnover is every stake added up, and turnover is the number the house edge multiplies against.
A C$200 bankroll played through a hundred C$10 bets is C$1,000 of turnover if half the bets return, and the edge is charged on all of it. Deposit size tells you almost nothing about what a session costs.
The unit system
Set one unit at 1% of bankroll and stake one unit per bet. On a C$500 bankroll that is C$5 a bet, and it stays C$5 whether you are up two hundred or down two hundred.
Talking in units instead of dollars also makes a record readable. Up eleven units over a season means something. Up C$317 means nothing without knowing what you staked to get there.
Where stakes creep
After a loss, because you want it back. After a win, because you are playing with their money, which is not a real category. And on the quick-stake buttons in an app, which are set at multiples designed to move you up a level with one tap.
Type the number rather than tapping the preset. It takes two more seconds and it keeps the decision yours.