Nice explaination
QFIT said:
If you can have an infinite bankroll and infinite period of time, then you can have an infinite losing streak starting right now. Again, you cannot assume infinity for part of the problem and ignore infinity for the rest of the problem. If you run an infinite number of such potentially infinite tests and average the results, then YES, you WILL have an infinite losing streak starting at the first bet in one of those tests. (Actually, this will occur not once but an infinite number of times.) And the average EV will be negative.
Once you bring infinity into a problem, what goes for common sense isn't so common.
To add-on:
Consider sample of 2 trials: Assume win prob=0.49
You will lose both = (0.51)^2 == 1 out of 4 player will go broke
Now n=3, prob(lose all)=(0.51)^3 >0 == 1 out of 9 player will go broke
Now n=4, prob(lose all)=(0.51)^4 >0 == 1 out of 16 player will go broke
Now n=100000, prob(lose all)=(0.51)^100000 >0
1 out of <.....> will go broke
For every n, there will be a probability that you'll lose it all which can be very small tends to zero but will always be greater than zero.
For n=infinity,
1 in (infinity)*(infinity)=(infinity) player will go broke due to infinite losing streak.. sounds fun
On the graph posted here
http://www.blackjackincolor.com/useless4.htm
Player's bankroll is actually
growing/moving downward with time. It'll be up 99% of the time, but 1% of the time when it is -ive. -ive(value of -ive) will overcome the +ive. Whether u ends as a winner or loser, depends on when u ends the sample. But with time, your average bankroll is keep decreasing oscillating around -ev of the game.