Positional analysis: Running back

Starting Tuesday, we will begin a daily positional analysis of the New York Jets, looking back and looking forward.

Focus: Running back

Depth chart: Shonn Greene, LaDainian Tomlinson, Joe McKnight, Carlos Brown, Chris Jennings.

Expiring contracts: None.

Rear-view mirror: It didn’t turn out the way it was expected. Tomlinson outplayed Greene in training camp and won the starting job, emerging as a workhorse for the first eight games. Greene went through a phase where he tried to be like Tomlinson, becoming more of an east-west runner instead of north-south. The coaches got in his ear about it and Greene finished with momentum, coinciding with Tomlinson’s second-half fade. All told, Tomlinson and Greene combined for 1,680 yards, compared to 2,273 from the Greene-Thomas Jones-Leon Washington trio in 2009.

Numbers game: Greene’s average per carry dropped 18 percent from his ’09 number (5.0 to 4.1) while the team average dropped only two percent (4.5 to 4.4). What does it mean? The offense was able to maintain its efficiency on the ground even with the philosophical shift toward more passing, but Green failed to keep up with the Joneses’ – or, in this case, Tomlinson (4.2), not Jones … Tomlinson caught more passes (52) than any Jets back since Curtis Martin (53) in 2001.

Crystal ball: Barring something unexpected, the Jets will have Tomlinson, 32 in June, back for the final year of his contract. A new, restrictive salary cap could make things interesting, but it’s not like Tomlinson is making major bucks -- a relatively modest $2.4 million in base pay. Actually, this is one of the most cost-efficient positions on the roster.

The main issue is defining roles. McKnight’s athleticism and pass-catching are intriguing, but he has a lot to prove in terms of durability, pass protection and toughness as a between-the-tackles runner. Bottom line: The Jets don’t have a true No. 1 back, so it has to be a three-man committee.

Hot Seat: Greene. What happened to the back who dominated in the ’09 playoffs? Greene is entering the third year of a four-year contract, and if he wants to make a big score, he’s going to be a bounce-back season in ’11.

Position rating (scale of 1 to 10): 8.0