ALLEN PARK, Mich. -- Reggie Bush remembers his only game at Lambeau Field. His rookie year. Second game.

It did not go well. At all.

“I just remember that my head was spinning and I was trying to outrun everybody to the sideline,” Bush said. “And, just, being a rookie.”

Bush gained 5 yards on six carries, a rough indoctrination to life in the NFL. Then, though, he didn't know much about being a running back. In college, he had been used as a slashing player, lining up outside and inside, not always having to run between the tackles.

Not being a true running back.

If the description above sounds more like how Bush is being used now, that’s accurate. The Detroit Lions are lining Bush up a little bit of everywhere. But there’s a difference, a big caveat for the eighth-year player out of USC.

He knows how to run between the tackles now. He understands what it means to be an actual running back instead of a multipurpose player. And that has helped his career. Playing the position and actually being a running back who ran the ball with consistency in Miami also jump-started a late-arriving process.

“When I look back, I’m so much more advanced in just my vision, my understanding of schemes, linebackers, where they have to play their gaps and just all the different things that come along with being a running back,” Bush said. “So it’s taken a while. It didn't happen overnight. It took me a while, took a couple years.

“I would say it took a good four or five years until I really had a true, good understanding of defenses and schemes and how to run the ball.”

Bush started to understand things after the Saints won the Super Bowl in 2009. He didn't play much in New Orleans, and in 2011 he went to Miami.

There, Reggie Bush became an actual running back. He gained 1,086 yards his first season with the Dolphins. He came close to another 1,000-yard season last year, gaining 986 yards.

Then there’s this season, in which he’s on pace to rush for more than 1,200 yards, a number that would eclipse his previous career high.

Some of that is why he came to Detroit in the first place, because of the Lions' scheme, because of the potential of relatively wide-open spaces to run through due to the attention paid to wide receiver Calvin Johnson.

“It’s a little bit of everything combined,” Bush said. “Where they are using me and constantly moving all around. The way we’re running the ball, too. We’re not just lining up to run power all day.”

He may not be running power, but throughout the past six seasons, he has run more between the tackles instead of trying to get outside of them. Those final three seasons with the Saints, he ran 64 percent of the time between the tackles, according to ESPN Stats & Information.

His two seasons in Miami, that number jumped to 76 percent. Now?

A career-best 81 percent of his rushes are coming between the tackles, and he’s gaining 5.7 yards a rush when he does -- well above his previously stated goal of 4 yards a carry. On Sunday against Chicago, he had 139 yards rushing, his highest total since the second week of the 2012 season.

That he can do that and still keep his elusiveness has led to arguably the best season of his career.

“He’s a very strong runner,” Detroit coach Jim Schwartz said. “He doesn’t go down easy. I think that has served him well in any role that he is used in. We really can’t worry about what pace anybody is on. It’s a little bit like anything else.

“What happened in the past has happened. It has shown well that the combination of him and what defenses do, the plays that Reggie has made, have been because of the attention that Calvin has gotten. Eventually, teams are going to have to loosen up on Calvin, or Reggie is going to continue to have big days like that. That’s a good position to be in offensively.”

And just as Bush has aided Johnson, the presence of Johnson has opened up those spaces for Bush. And as much as the scheme is helping, Bush’s understanding might be more important.

“He’s really helped their offense stay in the balance,” Green Bay coach Mike McCarthy said. “And really challenges schematically as far as the runs and the quick screens and the action pass game all looking similar.”

That brings it back to Green Bay, to the second game of Bush’s career and a game he’d rather not remember. Packers quarterback Aaron Rodgers, who barely played himself that game, remembers that his defense “got after him that day a little bit.”

It is something Bush would rather not have repeat itself again on his second trip to Lambeau Field, this time as a veteran in a system that fits him perfectly.

“It wasn’t a successful day,” Bush said. “I look forward to hopefully a successful day this Sunday.”