Federer's success on 1st-serve points in today's loss to Djokovic was just 56%, lower than it has been in any match in their rivalry
. It has been higher even in losses that were more one-sided than today's -- like their Dubai final last year (6-3, 6-3 to Novak).
When Federer lost in straights to Djokovic at the AO in '08, he won 70% of his points on 1st serve. When he lost to him in straights again at the AO last year, he was up at 72%.
Today in the second set, Federer dropped to 40% success on 1st serve (46% on second).