k_c said:
What we seem to have is a battle of dueling infinities.
Case A
On one hand it was shown that for an unlimited bankroll a negative EV game's martingale losses will approach infinity. In other words no matter how large a bankroll is defined it still won't be enough and the martingale eventually fails.
Case B
On the other hand is the claim that there is a bankroll big enough that it will never be depleted no matter what, even if martingaled when EV = -99.999999999...infinite number of 9s%.
Case A proves Case B to be false. However proponents of Case B refuse to believe that so there seems not much left to say.
Sorry, I don't believe it because you are still mistaken. Case A does not prove Case B to be wrong. Case A requires an a priori specification of bankroll size, while Case B defines it to be sized enough to achieve one win.
One very clear error of yours: -99.9999.. is exactly equal to -100.
(proof) So you can't have that as a condition of the problem, since there must be non-zero odds of winning. There is no battle of infinities. This must be where you're hung up.
Once again, the problem statement, simplified:
1. I can make any sized bet I want.
2. Every bet is chosen such that, if it wins, I come out ahead overall.
3. I have a non-zero chance of winning a bet.
Any problem with those conditions?
4. If I have a non-zero chance of winning a bet, eventually, I will win it, per my response to QFIT. That's by definition. If I never have a chance to win it, P(win)=0, which violates the condition of the problem.
5. Therefore, if I
ever win a bet, I will come out ahead.
6. Since I will always eventually win a bet, I will always (eventually) come out ahead.
Where is the logical violation in the statements above?
I have no problems with people correcting old luminaries, but I'm sticking with Thorp on this one, because he was right. You've done a good job proving your case for a finite bankroll, but the proof does not apply to an infinite (unlimited) one, where the bankroll is always big enough to allow at least one win.