LOS ANGELES — Stafford Mays didn't let his son Taylor play football until the seventh grade. The kid had to dip his toe in soccer and baseball first.

Finally, Taylor got to put on the helmet for his first practice.

That night Stafford went upstairs to see how Taylor was handling his math homework.

"He still had the helmet on," Stafford said.

Yeah, you never know when one of those fractions is going to leap out of the book at your head.

Anyway, Stafford pretty much knew which direction Taylor was going. And it made sense. Stafford played defensive line at Washington, and then nine years in the NFL, with the Cardinals and Minnesota. One of the Vikings' assistant coaches was Pete Carroll.

Funny how equations can balance.

Now Taylor Mays is the 6-foot-3, 230-pound guided missile who plays free safety for USC and, in that capacity, has the best view of perhaps the best defense in Division I-A, or whatever they're calling it these days.

Mays is a junior who is being variously projected from the low 20's to the mid 30's among 2009 NFL draft picks, if he chooses to come out.

"I'm just trying to execute and impose my will on the offense," he said while signing autographs after Tuesday's practice.

Yet a couple of weeks ago, Taylor called home to Seattle and told his dad he was actually a little depressed. No receiver was feeling masochistic enough to come down the deep middle, he said.

The Cal game fixed that. The Bears tried to throw into Mays' territory, which basically ranges to the hash marks, and Mays performed some of the headbanging that the pro scouts wanted to see.

"He doesn't get to make the big hits that often," said Stafford Mays, a Microsoft executive. "Even in high school up here, a lot of the teams specialized in the running game."

Carroll, an old free safety himself, believes that the midst of the field is sort of like the strike zone. Prove you can take it easy, and now the pitcher has to squeeze the ball into tight corners, and the percentages desert him.

"That's where a lot of the plays are made," Carroll said. "I've talked to Taylor a lot about what the position demands, what opportunities there are. He's a very advanced learner. We've been able to take away that part of the field most of the season."

The Trojans rank first nationally in total defense, scoring defense and pass defense. They have given up seven touchdowns, four in one game (Oregon State). In 113 drives against USC, opponents have traveled 50 yards just 11 times.

Since Stanford is averaging 27.6 points and hasn't been held to single digits by anybody, it makes for a thicker plot at Palo Alto on Saturday. Still, nobody expects the Cardinal lab rats to catch lightning in a Bunsen burner two consecutive years.

The real intrigue would come if the Trojans ever got a chance at Texas Tech or Missouri or another offense that plays a chorus line of receivers. Few teams can cover everybody. USC might be one, with

Cary Harris, Josh Pinkard, Kevin Thomas, Will Harris and Mays. Not all of them are true cornerbacks, but it would be a challenge the Trojans would accept.

If Mays had come along in the 1990's he might have well have stayed home. Washington was playing major college football then, and Stafford took Taylor to every Huskies game.

"We let Taylor make his own decision," the dad said, slyly. "But I did maybe guide him a little bit.

I pointed out that USC had just won a national championship, and that I knew Pete Carroll, and that when I was with the Vikings, Pete had made Joey Browner and Carl Lee into Pro Bowl safeties. So, yeah, those things might have had an influence."

By then Stafford was pretty sure his son would land successfully somewhere. When Taylor tired of playing baseball, Stafford gave him two choices: work at the local grocery store, or run track for O'Dea High.

"I'll run track," Taylor replied.

Mays won a 3-A state title in the 100 and 200, with a top 100 time of 10.88.

"Charle Young played at USC and for the Seahawks," Stafford said, "and his son Chancellor was the fastest guy around. I picked up Stafford at school one day and, real quietly, he said, 'You know, I beat him in the 50 today.'

"But then I would watch Taylor run downfield on kickoffs and he would always be first. I said, 'Is he that fast?' I guess he was."

The Stanford receivers can figure out the sum of their fears. They've been wearing their helmets all week.