By analysing opponent's games he was able to learn his strongest and weakest sides and then make use of this findings during actual game. Lasker avoided positions where the opponent mastered and felt comfortable. Instead, he steered into areas where the opponent disliked and played inferior moves most frequently.
The problem is that Carlsen has no weaknesses and is comfortable in every position.
I think he is not as perfect in rook endgames as in the others. His recent losses all resulted from blunders in rook endgames
By analysing opponent's games he was able to learn his strongest and weakest sides and then make use of this findings during actual game. Lasker avoided positions where the opponent mastered and felt comfortable. Instead, he steered into areas where the opponent disliked and played inferior moves most frequently.
The problem is that Carlsen has no weaknesses and is comfortable in every position.