Defend or Attack

This is the usual dilemma for most of the chess players, when to attack and when to defend. While it is unique for every position , I have the following example of a game played, where the white is quite confident of the next few moves of attack and  finishing the game. 

The important move to note here is the sacrifice of the knight when the queen enters the white's territory in the 7 th rank of Black[ 2 nd rank of White]. White took a bold step of attacking the king leaving  very little chance for winning. 

Click to watch the game