For that to be "obvious", the 10% estimate should be objective and not just pulled out of thin air by somebody. And if it is statistics-based, it should hold into the future even though conditions change all the time (no idea how you would guarantee that). Even then, it's not that obvious - you can't pay rent with a 10% chance. Surely, if you take such chances regularly, it would pay you rent on average, but if you do it just once, you'd have to think about how much not being evicted from your apartment when 90% chance plays out instead costs to you.