FOXBOROUGH - Former Houston Texans general manager Charley Casserly watched video of everything but the births and baptisms of running backs Laurence Maroney and Joseph Addai before the 2006 draft, trying to decipher which one was better suited for the NFL.
When taken anonymously, his observations are telling: Running back No. 1 - "Has speed and makes big plays. Can get to the corner and hit the seams for big plays. Will make big plays with the ball on screens and swings." Running back No. 2 - "North-south physical runner, quick cutter, can run the stretch play and accelerate."
The first assessment is of Addai, the second of Maroney.
Separating Addai and Maroney is an inexact science. The two were taken nine spots apart in the first round of the draft: Maroney went to the Patriots with the 21st overall selection and Addai to the Indianapolis Colts at No. 30. As elusive as the runners are, they can't get away from each other, inextricably linked by their position, their draft status, and the teams for which they play.
"I think they're both good backs," said Casserly. "The difference is Maroney has missed more time than Addai. That's the difference - the missed time and some hesitation or dancing or extra steps in the backfield, as opposed to more decisiveness from Addai. But they're both really good backs."
With the Patriots and Colts renewing their rivalry Sunday at the RCA Dome, it's another chance to revisit the Maroney-Addai debate. The two are running on similar platforms, but while Maroney was the front-runner coming out of the University of Minnesota, Addai, who played at Louisiana State, has surged ahead after a season and a half in the NFL.
Addai, who led all rookies in rushing last year with 1,081 yards, is third in the NFL in yards per game (98.7) this season, with 592 yards on 123 carries, a 4.8-yard average. His seven rushing touchdowns lead the league, and he has eight scores overall. He is the primary ballcarrier for the Colts, who have the fifth-ranked run offense in the league at 140.3 yards per game.
Coming off a promising rookie season, Maroney also is averaging a robust 4.8 yards per carry - 74 rushes for 358 yards. But he has yet find the end zone, and has had to endure both nagging injuries and nagging questions about his durability and running style. A groin injury sidelined him for three games, and he has carried the ball 20 times just once this season, logging 20 rushes for 72 yards in the season opener against the New York Jets.
Coming out of college, Addai was the one with durability concerns, an ankle injury that hampered him during his senior year and concerns about a torn ACL he suffered in high school. However, he has played in 26 of 27 games, including the playoffs, since turning pro, and this season has had 20 or more carries in four of the six games he's played. He had 19 carries for 136 yards against Denver Sept. 30 before being forced to leave the game with a bruised shoulder.
Maroney said he feels he can carry the load like Addai and be an every-down back.
"Right now, I'm just playing my role and that's whatever role they have for me," said Maroney. "If they need me to carry a load this game, then I can do that. If they need me to have a lesser role, then I'm going to do that. I'm just a team player. I'm going to be prepared and ready for whatever they deal my way."
The two are friendly rivals. They text and talk on the phone. Maroney said he'll call Addai after a game to offer his encouragement. This week he called him for help.
"I just talked to him the other day because I needed some tickets," Maroney said. "He ain't call me back yet."
Maroney's admiration for Addai is obvious.
"He's one of those backs where when he gets the ball in his hand, you get a little nervous because he can beat you in all different ways," said Maroney. "He can outrun you because he has the speed to outrun you. He has the moves to run around you, and he's a powerful runner. Me being on offense, when I see him get the ball, I'm just like, 'Man, get this guy down by any means necessary.' "
When it was suggested that description fits a certain Patriots runner who wears No. 39, Maroney turned modest.
"No, not like me. I'm all right," said Maroney. "Addai, I really like his game. I really do. I tell him every day after games. I'll text him and tell him, 'Good game, man. Keep running hard.' That guy definitely runs hard and he's definitely a great back."
The Indianapolis system of zone blocking and one-cut runs seems perfectly suited for Addai's skills. Maroney played in a zone-blocking scheme at Minnesota, and the Patriots have made a move to incorporate more zone-blocking plays into their offense this season.
Casserly acknowledged that a running back's success can be tied to the system he plays in, but he said that hasn't slowed Maroney.
"I didn't view Maroney as a guy that needed a system," said Casserly, who after passing on running back Reggie Bush to draft Mario Williams with the No. 1 overall pick in 2006 had designs on drafting Maroney. "I thought he was a good back in any system. I thought it was a great pick, and I was upset because I wanted him.
"We had Maroney ahead of Addai. We tried to trade up for Maroney. We had heard rumors about the Patriots taking him. We couldn't get that high. We were hoping to get into the 20s and take him, and the Patriots took him and we never got to make the trade."
In a sign of Maroney's maturity, he was careful to stress that he's not matching up against Addai; he's tackling the Indianapolis defense, or more accurately, they're trying to tackle him.
"They're good. They got a lot of movements and they're a good run-stopping team," said Maroney. "They got a good defense this year, and their movements are going to be scary. We haven't seen too many teams that stunt and do as many movements as they do. We just have to be patient and hopefully get a block on everybody."
Patience is a virtue for any good runner and for anyone comparing Maroney and Addai.
The debate that started before the 2006 draft isn't over. It figures to be a long-running one, and that's just the way both running backs want it.
PATRIOTS CHAT: Mike Reiss today at 1 p.m. on boston.com/sports.