I think that he turns his temper on other people when he loses gambling like my father used to.
Transfer of aggression is also one of the most annoying behaviors that I dislike about gamblers, which I notice is common among most gamblers. Why do you have to transfer aggression on anyone after losing? No one forced you to gamble, and the people that you are transferring aggression on are not the cause of your loss. I think any gambler who loses should just be calm, and they don't have to blame anyone or transfer aggression on anyone. I know it's painful when you lose, but you just have to stay calm. Being aggressive won't solve any problem, you just stress yourself, and it's going to disturb your mental health.
When he came home he threw all his anger at me when he saw me. Of course not only me, but also my brothers I don't know why. I still remember when it was my birthday, my classmates went to our house to have fun and of course to eat then dad came home from gambling and dad saw my classmates and suddenly slapped me in front of my classmates.
That's really bad. Your dad is too harsh. I don't know if your dad depends on gambling as the only source of income. Maybe he is addicted to gambling, or maybe he gambles with a large amount of money. Maybe that's why he is always in pained after losing. I'm just surprised that your dad do hit you after losing in gambling. That's really bad. But after winning, how did he behave towards you and your brothers? If I am you, I will always avoid my dad when I notice that he lost a bet to avoid pouring his anger on me.
I hate it when gamblers complain of not having money. For heaven's sake, how do you expect to have funds when you always gamble without winning. And then you get a tip, or you get paid your stipen or even salary, the next thing is gambling and you loose everything and just minutes after that, you see them complaining about how broke they are, the funniest part is, if you give him money, he's headed towards gambling again.
The only set of gamblers that I notice this behavior from are the addicted gamblers. They are the ones who spend all their money on gambling, and at the end, they will end up complaining that they don't have money after spending all their money on gambling. But responsible gamblers always know when to stop. They have an allocation that they spend on gambling, and immediately after it has finished, they will stop gambling even if they have more money.