In my country (Australia) ALL gambling winnings and profits are 100% tax free.
You don't have to declare it because it is considered a hobby.
In the USA and other countries gambling winnings are treated the same as income and gambling companies are required by law to withhold federal income taxes.
If I had to pay taxes I would quit gambling. The risk wouldn't be worth it.
Does your country tax gambling winnings and if so do you declare it yourself or does the gambling operator withhold the taxes on your behalf?
Yes, there are taxes and the operator withholds and pays them himself. In the annual declaration, you can write only part of the net profit after taxes. I think that not taxing winnings will be a serious loophole for money laundering through, for example, fixed matches, for example, you can spend large sums. And so with The state has minimal control over the players.