CINCINNATI – Ask Perry Brooks Jr. about younger brother Ahmad's most athletic feat, and there's a long pause and then a long list. The stories come chronologically.

There was the time Ahmad, a 9-year-old cornerback, skied above the scrum on a deep pass and returned the interception 75 yards for a score.

A few years later, Ahmad, this time at running back, had a carry that would have made Barry Sanders envious. He weaved, faked and dodged defenders – two crashed into each other – for a 60-yard touchdown.

In high school in Woodbridge, Va., Ahmad won a dunk contest with a thunderous 360-degree slam. While playing middle linebacker at Virginia, he recorded a sack against Virginia Tech by leaping, leopard-like, over the nose guard and center and crashing into the quarterback before he could take two steps from the line of scrimmage.

Ahmad Brooks made it look easy. And that was the problem.

"Ever since he was in little league, he could just get away with his raw athleticism," said Perry, who is four years older than Ahmad, 27. "It happened in middle school and then high school. They'd put him in the middle of the field and tell him to get the ballcarrier."

Today, Brooks returns to the city where he started his NFL career, but in a much better position than he was as a rookie in 2006.

There's a literal meaning to that. The Bengals took Brooks in the third round of the supplemental draft that year and lined him up at middle linebacker. The 49ers converted Brooks, 6-foot-3 and 265 pounds – into a 3-4 outside linebacker.

The figurative meaning, however, is more critical to his recent success.

Brooks talks about his two seasons in Cincinnati as if he were recalling another lifetime.

"I was still a baby," he said. "Maybe not in the public's eye. I mean, we're still considered men. But at the same time, I'm fresh out of college. I'm getting money now. I never had that much money for myself. And I enjoyed that."

Brooks, who ran afoul of Virginia coach Al Groh and was kicked off the squad after his junior season, said he liked to go out on Friday nights in Cincinnati. And on Thursday nights. And after games.

"And that affected my play on Sundays just a little bit," he said.

Still, Brooks was talented enough to start five games as a rookie. When the 2007 season began, he was the starter in the middle of Cincinnati's defense. But he suffered a groin tear in the second game. When he hadn't recovered nearly a year later, the Bengals waived him.

"He's been through a little bit, but he's really grown up as a player," Cincinnati coach Marvin Lewis said.

After signing with the 49ers in 2008, Brooks started acquiring skills – focus, dedication, discipline – his athleticism had made unnecessary.

Nights at the club were replaced with appointments with the chiropractor. He immersed himself in the cold tub after practices. He got weekly massages. Fast food was out. In were home-cooked meals prepared by his girlfriend, a dietician.

He also began to study. On the first play of the 49ers' third exhibition game this year, Brooks didn't bite on a Houston screen play. He followed the running back out of the backfield, intercepted the pass and returned it for a touchdown.

"The old Ahmad doesn't make that play," Perry said. "The old Ahmad would have said, 'I'm a better athlete than these guys. I'm going to go after the quarterback.' "

Brooks was limited to a third-down role in 2009, yet still finished with six sacks. Last offseason, he was gunning for a starting job. But at the beginning of training camp, he suffered a lacerated kidney when a blocking sled he had just thrown to the side struck the ground and sprung back up, striking him just below his ribs. Brooks missed a month, fell behind and was relegated to a backup role again.

This year, however, new defensive coordinator Vic Fangio searched for pass rushers and committed to Brooks early. He's starting for the first time since 2007.

And while Brooks has yet to record a sack, he had perhaps the biggest hit in last week's game against Dallas. Early in the first quarter, he burst through the offensive line and buried his shoulder beneath quarterback Tony Romo's outstretched arm.

The hit cracked Romo's rib, deflated a lung and led to the most discussed NFL story line over the last week.

"That's my job now," Brooks said. "I had a clean shot. I came right through the gap, right through the 'B' gap. He sat in the pocket. It was a clean shot."

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