Calling yourself profitable without a complete record.
A good week, one winning account, and a memorable payout don’t establish an overall profit.
Pick a time period and use the same dates for every account. Include cash bets, losing tickets, and fees. Don’t restart the count just after a bad stretch.
For an account that started at zero, with no pending bets, bonuses, or transfers to complicate things:
You deposited $100, withdrew $30, and have $40 you can still withdraw. That’s a $30 loss.
A $60 win along the way is already included. It doesn’t get added again.
Account histories are more reliable than the results that come to mind first. If the picture is complicated, start by collecting the records rather than filling the gaps from memory.
Sources & further reading
- Mean, expected value, and standard deviation
OpenStax. Definitions and worked examples for averages and variation in random outcomes.
Examples on this page are illustrative.