The primary driver of Nurmagomedov's effectiveness in the cage has been position control

When two fighters stand at a distance exchanging strikes, the game is all about hitting while not getting hit. But once the fighters make contact, it's dominant position that wins the round. 

The dominant fighter is the one who takes outside position while the two are clinched against the cage or the one who seizes top control on the ground, thereby stifling the opponent's ability to fight back, while keeping available his or her own offensive options.

In the clinch and on the ground, no one in the 155-pound division has been more effective at control after contact than Nurmagomedov...

Ferguson has nearly one submission attempt per trip to ground, far above the average. 

But Ferguson has lost rounds to wrestlers when they have been able to avoid or stifle his guard. So a matchup against Nurmagomedov would seem to be the ultimate test of top control versus a guard game.

http://www.espn.com/mma/story/_/id/22946628/the-statistical-domination-ufc-lightweight-khabib-nurmagomedov-grappling-control