It could be called the 7% solution, the margin by which USC's football program has slipped in the '80s compared to the rise of UCLA.
Foster Andersen, a former UCLA player who later was an assistant coach at both USC and UCLA, arbitrarily arrived at this figure. He said that while USC was dropping about 5% in quality, UCLA was making about a 2% ascension.
This decade, so far, belongs to UCLA with five wins over USC in the last seven games. It was the reverse in the '70s, when the Trojans had a 7-2-1 margin over the Bruins.
"However, the gap between the schools has never never been that great," Andersen said. "There's a misconception that somehow UCLA hasn't been that good in the past and has just recently become prominent under Terry Donahue.
"That's nonsense. Red Sanders had success in the '50s. Tommy Prothro was successful in the '60s, and Pepper Rodgers and Dick Vermeil had their share of success.
"There was a gap in favor of USC in the '70s when John McKay and John Robinson were coaching the Trojans. But most of the games between the schools then were extremely competitive.
"When you look at UCLA's football history, it's pretty impressive. But the Bruins share the same town with USC, which has a great history."
Asked to cite reasons for USC's relative decline and UCLA's preeminence, Andersen said:
"I think USC slipped because of internal reasons. USC has hurt itself more than it has been hurt by UCLA.
"A couple of major things occurred. USC was placed on NCAA probation for two years with no bowl or television appearances. The NCAA doesn't put you on probation so it doesn't hurt you. It does hurt you.
"What it does to a major power is take away that extra 5% that provides a school with a few great players, even though USC continued to get good players.
"USC has a very fine football team now and is very competitive, but it's not a great team in the context of USC football. Some people act like the probation thing didn't happen, but it had a major impact on USC."
Even though Andersen played for UCLA in the early '60s and was a UCLA assistant coach under Donahue in 1977, he is more closely associated with USC. He was an assistant under McKay and Robinson, and later Ted Tollner.
When Tollner was fired last December, Andersen and other members of the staff, with the exception of Ron Turner, also lost their jobs.
Andersen now runs an evaluation service of high school and junior college players that is available to universities.
He is still a friend of Donahue, though, and also maintains his USC ties.
"From 1979 on, UCLA was recruiting better," Andersen said. "Previously, USC was getting national exposure on television and doing a good job of recruiting blue-chip out-of-state athletes such as Marvin Powell, Gary Jeter, and Chip Banks.
"Then, suddenly, USC was off TV and, at the same time, UCLA made a major recruiting effort and hired a recruiting coordinator, Bill Rees, who has done a great job.
"So you take the ingredients of a very successful football program, a very likable and intense coach in Donahue, a very thorough recruiting system and, all of a sudden, UCLA has a national reputation--more of an image than it had before."
Andersen said there is another factor in UCLA's surge in the '80s, a rededicated Donahue.
"The 1979 USC-UCLA game which USC won, 49-14, after leading 35-0 at halftime turned Terry into a one-dimensional zealot," Andersen said. "He was so embarrassed and so mad that it just increased his intensity to beat the Trojans."
Donahue was 0-4 with USC then. He's 5-6 now.
It has been suggested by some sportswriters and UCLA alumni that much of Donahue's success in recent years could be attributed to Homer Smith, the former UCLA offensive coordinator, who now works with the Kansas City Chiefs of the National Football League.
"Building up Homer at the expense of Terry was a big mistake," Andersen said. "I think Homer is a fine coach and played an important part of history for UCLA and Terry.
"But coordinators don't run football teams. Head coaches run football teams. They set the tempo, goals and environment. Coordinators do what head coaches want them to do."
Andersen said that USC has done a respectable recruiting job in recent years, getting good players, but not many great ones.
He specifically referred to the the demise of the tailback position until this year, with Steven Webster injury free, emerging as the leading ground gainer in the Pacific 10.
"That's where we got in trouble was the tailback position," Andersen said. "We didn't have the guy who made the formation work.
"There is no better example of that than Webster. Before Webster started this year a lot of people were down on (quarterback) Rodney Peete, saying he couldn't do this, or that.