what I meant, is that the year end rank is just an arbitrary point in the year, sure it sounds nice though
but its not much different than having a 'mid-year no.1' or 'end-of-April no.1'
the total number of weeks at no.1 is a much more useful assessment of player's career, but I think even this can occasionally be slightly overrated/overstated (as seen in the WTA), slams are what really matters
That's true. Every week, the rankings always reflect the best player during the last year, but like most sports, a year-end statistic is needed. There is no mid-year no.1 or end-of-April no.1, because only the end of a year has enough significance for everyone.
"I was the best in 2012" is a good morale drive for 2013.
It can happen that a player loses the No.1 in the first week of the following year, after achieving the spot during WTF. That seems arbitrary, because it may happen anytime during a year. But, if on December 31st, I am No.1, it means I was the best during the ending calendar year.