Why is Notre Dame not in a conference for college football? Here's what to know as the Irish are set to compete in the CFP championship game on Monday:

Ohio State coach Ryan Day spent the weekend celebrating the program's ninth national championship, a crowning achievement for a group that had operated like one of the best teams in the country all year and then played some of its best football in the biggest moments with a challenging run through the College Football Playoff.

Ohio State started the second half strong as well as they scored a touchdown on their first drive, and then they kicked a field goal after Notre Dame failed to convert a fake punt. It was 31-7, and the Fighting Irish were showing no signs of life. Then, everything changed.

How many national championships does Notre Dame have? Here's the full list of the Fighting Irish's championship history: