Karjakin plays very accurately to defeat Navara's French Rubinstein. If you're going to play 3.Nc3, you have to be prepared for several mainlines, including in particular the Winawer, the Classical, and the Rubinstein. (And note that Tarrasch players (3.Nd2) have to be equally prepared for the Rubinstein.) You'll also need to look at several minor lines, including 3...Nc6, 3...c6, 3...c5, 3...Be7, and 3...h6. We'll take a look at each here with time.