I think luck only plays a very small part in success. In other words, luck is minor factor in success. Like a suddenly rich man, you can be successful with a moment of luck, but I don't think it well end well. There is a saying in Korea, "Chances come to those who are prepared." As the sentence means, luck doesn't affect success muck because opportunities will come to the prepared person. If a prepared person takes the opportunity and not only makes good use of that opportunity, but also has luck, success can be achieved. Therefore, I think effort and preparation are more important than luck.