Eli5: Why can’t you just double your losses every time you gamble on a thing with roughly 50% chance to make a profit

Question

This is probably really stupid but why cant I bet 100 on a close sports game game for example and if I lose bet 200 on the next one, it’s 50/50 so eventually I’ll win and make a profit

In: 4566

Answer 1

Your expected profit just isn’t realistically worth it.

Say you start with betting $1 and you lose 5 times, until you win. In this case on the last bet you would be putting in $16 to win $32 dollars, giving you a profit of $16. However if you add up all the losses of the previous rounds, 1+2+4+8 = $15. Therefore your true profit is $1.

This method basically guarantees a $1 profit, but no one has infinite money and the chance you hit a bad streak is likely over time.