It is spreading as a cancer. This month the central bank published a report saying that in August 20% of the Bolsa Família, the largest money transfer program for very poor Brazilians, was spent on these bets.
Out of the 20 million people that receive it, 5 million made bets during that month. This is 2 billion reais (about $450M) spent in a single month by the poorest Brazilians.
It's a cancer. Everywhere you go there are ads. The influencers, the biggest athletes and musicians are marketing it.
Although I tend to be liberal, this needs to be heavily regulated.
The first time I went, people were living off the land, fishing, gardening, children playing ball games, etc.
Here's what I saw last time I went: Gambling, alcoholism, plastic waste, sugary drinks, public advertising, and kids glued to their smartphones. Forests being cleared to raise cattle because now everyone wants to eat burgers.
They've managed to bring in the worst parts of modern society without the good parts (medicine, infrastructure, education, etc.)
I do believe that without a modern education, these people are not equipped to deal with modern vices. They've never taken a math class let alone learned enough probability to know that gambling is a losing bet. They've never had a nutrition class to learn that Coca Cola is disastrous to your health.
This isn't limited to the third world. The reason sports betting becomes such a problem is that people don't have a solid foundation in basic statistics.
People go bankrupt by thinking they can get out of a small debt by placing even larger bets at a negative expected value.
If you just gotta have a betting system because it helps quell the gambling anxiety or whatever, reverse martingale is fine. I made a video a long time ago about how it works[0] - but in essence, you only stand to lose your initial bet, and you have a bet schedule if you start winning. In "bet units" the way i do it is 1 unit until a win, then for each consecutive win: 2, 3, 3, 4, 5, 5, 5, 5 (etc). Everything after the first 3 unit bet is the casino's money you're gambling with, which is a good feeling. Note, this implies i consider each "round" that starts after a loss as separate from other rounds, obviously if you lose 20 times in a row and then win 3 games you're not suddenly in the green!
There's no system guaranteed to make you winner, but there are systems to help you lose more slowly, and reverse martingale is my go-to