BEREA, Ohio -- When describing the running back position, Cleveland Browns coach Mike Pettine said he's looking for a high-performance vehicle.

That would make Ben Tate a family sedan in this equation -- good gas mileage, dependable, but zero to 60 can be a problem.

Isaiah Crowell and Terrance West have combined for 72 carries the past three weeks because they don't have that problem.

"Three's an explosiveness there with the young backs, just a little bit more pop," Pettine said. "We wanted to see those guys out there. Sometimes it's not a matter of a negative against a guy, it's more of a positive with the other ones. We take everything into account."

When asked whether any attitude problems prompted Tate's lesser workload, including two carries for -9 yards Sunday against Houston, Pettine said, "nothing that I would speak on here."

Tate said last week "I'd be lying" if he said he was happy with the three-back committee employed in a Nov. 6 win over Cincinnati, where West got 26 of the Browns' 52 carries.

A week later, Crowell led the backs with 14 carries.

Since combining for 202 yards in back-to-back wins over Tennessee and Pittsburgh, Tate is averaging 1.7 yards per carry in his last five games (90 yards on 53 carries).

The Browns could still use Tate because of Crowell's fumbling problems and West's up-and-down season. Tate's an adequate pass-catcher out of the backfield who has carried games in the past. To the Browns, however, there's simply more promise with the rookies.

Crowell got the starting nod Sunday because he practiced well, rushing for 61 yards but costing the Browns points on a critical second-quarter fumble.

"Sometimes it's all close," said Pettine of the weekly evaluatoin process. "We also look at running styles vs. a particular opponent -- who executes these particular runs the best? It's more than just, 'Hey he looked better in practice than he did.' Sometiems it's a style/matchup decision."

The question becomes, how does Tate reinvent himself here? Clearly the Cleveland experiment hasn't gone as planned. Can he become an effective third-down back for the final six games?

With the Browns' fickle rotation, anything is possible. The most likely scenario seems to be Crowell and West splitting a bulk of the carries.