The magnitude of the bet is irrelevant yes. I was simply exploring the notion that if you can beat that breakeven point (>51% win in your example WickedBoy), would Martingale make sense from a mathematical point of view in expected return per bet since all non-max losses are wiped out with scaled wins, and the occasional max loss is covered by the intermittent wins.

It just feels logical that if you've been able to improve your odds of winning without affecting the payout, then it makes sense to compound the "unlikliness" of losing anything by using Martingale.

I think the significant thing that I overlooked here though is that in order to be able to survive a maxloss, your initial bet has to be much lower since it ramps up exponentially. Whereas without martingale you can stay somewhere in the middle of that bet size range and net a better result (see 0.41 vs 0.6 comment from Petra).

Also the point you make about finding a great system upside down got me excited back in the day too! I was still working on the idea of this Martingale thing working and so just needed any old system that was consistent, win or lose, and I'd reverse the signals if it was consistently losing XD. Couldn't even manage that. Everything I tried seemed to be nearly equally random, with any improvements between systems almost certainly put down to over fitting to historical data. I managed to get a couple of ideas to give good results in a walk forward optimization but as they say; throw enough sh*t at the wall and something will stick, so I wasn't convinced...