Andy Murray says he may need number one Novak Djokovic's form to dip to have a chance of victory in the Australian Open, which starts next week.
The Briton has lost four finals in Melbourne - three to Serbia's Djokovic.
"You just have to keep trying to learn, watch his matches, see if there are any weaknesses you can capitalise on," said Murray, second in the ATP rankings.
"Maybe he has a drop-off. It's very difficult to maintain that level for such a long period."
Murray, 28, lost the 2010 final to Roger Federer, before suffering defeat by Djokovic in 2011, 2013 and 2015.