Are we talking about scoring in the Red Zone or just TD's in the Red Zone?
Rather than just the %, I think the TD/Score per number of trips would be relevant too. If a team is in the Red Zone 3 times as many as another team, that percentage is likely going to go down a little. 1 TD in one trip to the Red Zone is the same percentage as 30 TD in 30 trips but the latter is a far different accomplishment.
My memory isn't great so I don't recall an excess of failed trips into the Red Zone for the Rams this year but even if they have, if they get there twice as much as the next team, they can be 50% as efficient and still out score them.
