On Thursday, the Penn State NIttany Lions will take on the Notre Dame Fighting Irish with the winner moving on to the College Football Playoffs National Championship game on January 20.

Penn State entering game week is a two-point underdog to the Fighting Irish who knocked off Georgia in the Sugar Bowl this past Thursday, 23-10. While there is plenty that of course will decide if the Nittany Lions or Fighting Irish move on, there are three matchups that may go further than most in deciding Thursday's semifinal.

Below, Happy Valley Insider takes a look at three of those critical matchups.