SAN JOSE, Calif. — They stand at the brink of history.

Both Alabama and Clemson have the chance to achieve what has never been done in the modern history of college football. By the end of the day on Monday, one team will finish a perfect 15-0 season. Sages and scribes will discuss whether that is the greatest team of all time, comparing it with 2001 Miami, 1971 Nebraska, 1956 Oklahoma, 1945 Army and a connoisseur’s choice of great and undefeated Notre Dame, Ohio State, USC and Texas teams of the past in debates that can never quite be settled.

The other team will occupy a smaller category, that of the foil in great rivalries — Alydar, the great thoroughbred whose losses to mighty Affirmed were only a part of his tragedy, or Joe Frazier, who conquered Muhammad Ali only to see Ali regain the mountaintop in Manila, or Wilt Chamberlain’s Philadelphia teams that could never get past Bill Russell and the Celtics. Those stories represent a different sort of legacy, one conferred by time, not triumph.

The national championship will assign those roles, perhaps fairly, perhaps not. Great teams can lose a single game — a great team will lose Monday. Alabama’s 2016 team is rated as something of a disappointment because of one game — one play, really. Yet it was a great team and part of the process that is ongoing, the history that has already been made by Alabama players who will step on the field in Santa Clara. No other players have ended their career by playing for a national championship in every single season at the school, not in the bowl era nor in the playoff permutations that have followed.

The arc of Alabama versus Clemson has been longer than that four years. The seeds of Monday night’s game began, arguably, in Atlanta when the 2008 season began. Alabama went in as an underdog in Nick Saban’s second season. The Crimson Tide came out with a 34-10 win and a roster dotted with names that would start a dynasty — Julio Jones, Mark Ingram, Dont’a Hightower, Marcell Dareus.

For a stunned Clemson, the loss ignited a process that led to the midseason resignation of head coach Tommy Bowden (a former Alabama assistant coach because, of course, the Alabama ties to the Clemson program are infinite) and the hiring of Dabo Swinney, the wide receivers coach, as the interim. His main competition for the job was defensive coordinator Brad Scott, for those who like to consider how history sometimes turns on the head of a pin. Clemson’s ascent took longer than Alabama’s — Saban was hoisting a crystal football in 2009 — but the two paths came together in 2015 and have run parallel ever since.

The path may continue well into the future. Make no mistake, one subtext to the eight-team playoff movement is to inject a little added hope that some upstart might beat the two usual suspects, but Swinney had the right attitude about that on Sunday.

“I’m not going to apologize for having a great team and great program,” Swinney said. “Neither is Coach Saban.”

Eventually, some other team is going to step up. Georgia was overtime-close last year. Ohio State is bringing in a new coach, which could go either direction, but if he can break the trend of one inexplicable blowout per year, the Buckeyes can contend.

This, however, is not their day. It will belong to someone else, either Alabama or Clemson.

They stand at the brink of history. And one is about to kick open those golden doors and walk in.

Reach Cecil Hurt at cecil@tidesports.com or 205-722-0225.