Who's the greatest player of all time?

If I were to answer my own question, I would say, there's no one greatest player of all time. Every generation has it's great players. Micheal Jordan is not the greatest of all time contrary to popular belief. He was just the greatest of his time. Saying Micheal Jordan is the greatest is just like saying he was greater than Wilt Chamberlain or Bill Russell. We will never know because they never played in the same time frame. Lebron James may be better than Jordan, but we will never know because they never played against each other. It's true that Jordan won 6 championships in his time, but its also true that there's a possibility that he wouldnt have any championshipshad he came into the league the same year as Lebron and had to play against him. How can greatness be measured? Is it championships, because Bill Russell is the greatest in that department, scoring because Karim is the greatest there, leadership ability because Magic is the greatest, or a combination of all three? All I know is that every generation has it's greatest player and to say that there is only one greatest of all time is bogus and inaccurate.