Notre Dame-USC Rivalry: Greatest ‘What Ifs?’

What if @ReggieBush doesn’t push @MattLeinartQB into the end zone in 2005? Does @brady_quinn lead ND to the title game? @mattzemek & @nickshepkowski share massive “what ifs” in Notre Dame-USC history…

What is the greatest “What If” in the history of the Notre Dame-USC rivalry?

Matt Zemek of Trojans Wire:

There are so many possibilities to choose from here, all of them worthy of the best answer. What if Notre Dame wins in 2005 because the Bush Push — technically illegal back then but rarely enforced by officials — had been called? That certainly merits a think piece on its own.
What if Notre Dame wins the 1964 game in Los Angeles and wins the national championship? Does USC become the dynastic force it eventually became under John McKay, or would the Trojans have labored in Ara Parseghian’s shadow for the next 10 years? Parseghian did extremely well at Notre Dame, and yet his 3-6-2 record against McKay prevented the Irish from attaining even greater riches. 1964 certainly represents a huge turning point in the overall course of the rivalry.
What if Notre Dame holds down the fort in 1974, instead of allowing the Anthony Davis avalanche to continue? USC wouldn’t have won the UPI half of the national title (shared with Oklahoma in the AP poll). Parseghian might have left South Bend with another national championship. Would John McKay have felt it was time to leave USC for the Tampa Bay Buccaneers? Would USC have been as successful in the latter half of the 1970s as it turned out to be? Would the Trojans have won as many recruiting battles with a young coach named Terry Donahue at UCLA? So many questions emerge there.