Don't mention this to any Sooner or Longhorn fans, but Saturday's game between No. 13 Oklahoma and No. 15 Texas may be the least significant Red River Rivalry matchup in more than a decade. For the first time since 1999, neither team is in the top 10.

The Oklahoma Sooners against the Texas Longhorns at the Cotton Bowl in 2011. Getty Images

No other college-football rivalry can match Oklahoma-Texas as far as national poll significance over that span. The Sooners and Longhorns have both been ranked in the top 25 in 11 of their last 12 meetings—the lone exception was in 2005 when the Vince Young-led Longhorns decimated the unranked Sooners 45-12.

Among other major rivalries, Texas-Oklahoma's stiffest competition is the game informally known as the "World's Largest Outdoor Cocktail Party." Only twice have Florida and Georgia been outside the top 10.

The most-heated rivalry during this span could be the five meetings between Florida State and Miami, when both teams were in the top 10—compared to four such games between Texas and Oklahoma. But the Seminoles and Hurricanes also played three games in which both teams were unranked.

As one of the highlights of the Texas State Fair, the Texas-Oklahoma game, unlike some other rivalries, typically is held in early October. As a result, the teams have had fewer opportunities to drop in the polls.

—Andrew Kahn