the only baseliners who were able to maintain dominance for several years were Borg and Lendl but they played in an era where baseline points were less demanding due to racquet technology and facing many serve and volleyers. In today's game, a baseliner primarily faces other baselines and with the racquet technology, long rallies can be sustained over 5 sets. The type of tennis Novak, Nadal, Murray play is incredibly taxing on the body. Just look at how Novak plays, he runs all of the court defending, hitting off balance backhands and playing long points. It's simply way too taxing on the body to play this type of tennis when dominating like he did in 2011 and 2015.. Winning 3 slams, 5+ masters playing this type of tennis is not sustainable. Federer is a different player who has more weapons, plays shorter points and is more efficient with his strokes, he is like Sampras in this regard. Pete was able to sustain dominance for a long time due to his serve and ability to shorten points. There is a reason Agassi was up an down too, like Nadal, Murray and Novak, his game required longer rallies and too much physical output. Agassi, like Nole and Nadal, dominated in spurts, went away and came back. If these guys would've played in 70s-80s, they could've maintained the high level longer because they would've faced many S&Vers and points would've been less demanding, not the case today. I expect Nole to have an average 2017 and he may be back in top form by 2018 but his problem now is age...
