Federer's chances are the big first serves, net volleys, temperament in tie breakers.
Nadal's chances are with long rallies, longer matches, passing shots.
Federer will have one additional day to rest.
Finally, both are not at their best - Physically or form wise.
So, this will be a match between a 70% Fedex Vs 1 70% Nadal.
How reatinesd the better 70 will decide the result.