The author writes about the Martingale strategy, but not in its full version, but in a somewhat abridged version. At the same time, he does not mention what to do if, for example, we lose many times in a row. Let's say, 5 or 6 times. If after the third loss we need to return to the initial bets, then here too we may face an unfavorable series of losses. In general, I must say that in practice, losses several dozen times in a row are quite common. In theory, this is a very unlikely event, but in practice it happens unexpectedly often. This has nothing to do with responsible gambling.