The appointment of Geoffrey Ma Tao-li to succeed Andrew Li Kwok-nang, announced at the same time as the appointment of three non-permanent judges of the Court of Final Appeal, underlines the relative youth of the incumbent chief justice. Ma, at 54, is seven years younger than Li. However, all three new appointees to the Court of Final Appeal are older than Li. While Li is retiring at the age of 61, Mr Justice Robert Tang Ching, Mr Justice Frank Stock and Mr Justice Michael Hartmann are only beginning their tenures as non-permanent judges at the ages of 63, 64 and 65, respectively. By law, the retirement age of the chief justice is 65 but his term, like those of other judges on the Court of Final Appeal, can be extended by the chief executive for three, or even six, years. Li, therefore, could have stayed on for almost a decade - in theory at least. His early retirement, therefore, is a substantial personal sacrifice. The question is: why did he choose now? When he announced last September that he planned to step down this August, he explained that his early retirement 'will be conducive to orderly succession planning in the judiciary in the coming years'. That is undoubtedly true. The other permanent judges on the court are all his contemporaries, none of whom can succeed him except as a purely transitional figure. Even on the Court of Appeal, four senior judges are approaching retirement age. Installing a successor at this time will certainly help the new chief justice in the 'orderly succession planning in the judiciary', as Li stated. But there may well be another reason as well, equally if not even more high minded. By the time of Li's 65th birthday, in 2013, a new chief executive would have replaced Donald Tsang Yam-kuen. And, in Beijing, Hu Jintao would have stepped down as Communist Party general secretary. No one can tell for sure what the new central leadership's attitude towards Hong Kong will be. The expectation is that Xi Jinping, currently vice-president, will succeed Hu as party leader and head of state. But, when he visited Hong Kong in 2008, Xi called on the judiciary, the administration and the legislature to 'understand and support' each other. He was widely criticised in Hong Kong for not understanding the independent status of the judiciary, which is not part of the administration. Other senior leaders in Beijing have also expressed unhappiness with Hong Kong, while going out of their way to praise Macau for passing legislation implementing Article 23 of the Basic Law - legislation that Tsang has pledged will not be passed during his term. It is entirely conceivable that a new administration in Beijing would feel inclined to put pressure on our next chief executive to make sure the next chief justice was a little more flexible where the independence of the judiciary was concerned. Stepping down while Tsang is still in office is crucial to ensure that a younger man who shares Li's vision of judicial independence is installed early and will have time to put in place other senior judges to replace those about to retire. That is to say, Ma will have several years in which to identify younger men to replace all current permanent judges in the Court of Final Appeal, including a high percentage of senior judges sitting in the Court of Appeal. According to this scenario, by the time Ma reaches retirement age in 2021, Hong Kong would already have a chief executive and probably a legislature completely elected by universal suffrage. Thus, there would be less reason to fear for the independence of the judiciary. Much now depends on Ma. Frank Ching is a Hong Kong-based writer and commentator.