Football fans should ready their scrapbooks for Saturday's game between No. 1 LSU and No. 2 Alabama: They may never see anything like it again.

Based on their dominant results, the Tigers and the Crimson Tide may prove to be two of the best college-football teams in recent decades. To some, though, their achievements are partly due to a controversial practice that's come under heavy fire recently: signing more players than you're allowed to keep.

To promote parity, the NCAA limits the 120 teams in the top-tier Football Bowl Subdivision to 85 scholarship athletes each. No more than 25 incoming recruits are allowed to join a team each fall. But in some cases, teams have offered scholarships to more players than they can accommodate under those limits.

This tactic, called "oversigning," helps teams by giving them more options. Alabama has signed 137 players over the past five years, for an average of 27.4 per year. It signed 32 in 2008—a class that included nine starters on this year's team, plus Heisman Trophy winner Mark Ingram. This total places Alabama among the top five nationally in oversigning.

LSU has signed 126 players over the same period, which works out to 25.2 per year. That number is considerably lower than Alabama's but higher than many other top teams.