Determinism is absolutely true according to classical physics but quantum physics maybe not so sure.
In terms of social determinism, I don't believe in that. I do think statistics, odds, probabilities, all matter. If a person is born into a difficult set of conditions it's definitely going to be much more difficult to make a great life financially speaking out of it but it's not impossible.
People win the lottery against the odds in life. People become famous overnight and get rich once their talent/wealth is discovered. As we become more connected it becomes easier and easier to be discovered. But, being discovered also brings risk, as people tend to be jealous of others too.