A long-term winning sports bettor can lose most of his money at any time. Once, while studying biographies of gamblers through interviews, I came across a story by a founder of an analytical service for determining alternative sports betting odds. Unfortunately, I can no longer find links to this interview. He talked about his life and how he had been a successful gambler for some time. But then the market changed, and he did not have time to adapt to it and as a result lost a significant part of his personal bankroll. Until that moment, he considered himself a long-term successful gambler and even tried to teach others. But his failure made him think about the reason for his success and whether his success was accidental. However, can we say that there are long-term profitable gamblers whose success is accidental? Can long-term success be accidental at all?
Yes, and this is not uncommon because, in fact, even a long-term gambler can lose most of his money at some point because, no matter how good his strategies and analyses are, the betting market is dynamic and unpredictable and sometimes changes are too fast to adapt... casinos need to keep evolving to generate profit and the use of AI in their predictions is something recent and very useful, for example.
Regarding the story you mentioned, it is difficult to know who it is without more details, but it reminded me of another famous case of the gambler Billy Walters who was also extremely successful for decades and then faced difficult times when the market changed and his strategies started to fail. And that is why I have always defended that those who play professionally need to take their profits and withdraw them, instead of always reinvesting more and more... at some point everything will fall apart and it is important that you have built up a good enough reserve to come out victorious and say: "ok, now is the time to stop while I'm still on top".
Now, on the question of whether a gambler's success can be accidental... I think so, there are cases where people can have a winning streak by pure luck or by being in the right place at the right time, but the true test of long-term success is consistency because if someone achieves positive results year after year, it is difficult to attribute this to luck alone and not to solid methodology, as well as discipline to manage risks and learn from mistakes.
No one is immune to losses, not even the most experienced... the market changes, new competitors emerge and the best strategies stop working overnight... so we must all be humble and always willing to adapt because "to err is human, but to persist in error is stupidity"