Martingale does not work in a casino. That is why a table has a $10 min to $200 maximum. Seven losers in a row are common.
Old news. In 2007 Bodog advertised a 49% win rate in Blackjack. What they did was have a string of losers followed by a streak of winners. The latest math on random numbers was to use solar radiation. One evening I tried a $500 bet because it was the exact time by the sun's shadow as yesterday. I hit a streak of 10 hands with a split and double for up $6,000. The 11th hand I lost, dropped to $250, lost and quit up $5250.
I think it was just luck. I was using Martingale on other days because I was betting $5 table min, counting losers in a row, then when a winning streak hit, I upped the bet but these loopholes have been fixed long ago.