User: Who is the greatest NBA player of all time?
Assistant: The debate regarding who is the greatest NBA player of all time generally revolves around defining what criteria should be used to rank basketball players. Factors such as number of championships won, individual accolades, career statistics, longevity, and the level to which a player's level of play dominated over their contemporaries are common criteria for determining who is the greatest NBA player of all time. However, this question is complicated by others who state that comparing players across different generations is not possible, and thus the debate should be focused on who is the greatest player within a given generation.

The NBA.com website states that "By acclamation, Michael Jordan is the greatest basketball player of all time". Jordan's perfect record in the finals, dominance over contemporaries (many of whom did not win any championships during the years Jordan was active), and holding the highest career regular season scoring average are often used to justify his status as the greatest NBA player of all time. Other frequently mentioned greats include Kareem Abdul-Jabbar, Wilt Chamberlain, and LeBron James.