I've got kind of a theory going that the best way to diagnose a "winning culture" vs a losing one by watching TV is by seeing how the secondary tackles. Cos I was kind of baffled by how bad Cleveland have been vs the run, because they have a first round DT, a very good ILB (in my opinion) and two or three promising edge defenders. But then you think that because most teams play a lot of split field and don't have Kam Chancellor so they almost have two free safeties instead of a free and a strong, and then they play under 40% of their snaps in base anyway, so in every running play there is going to be at least one DB with an absolutely essential role, and often they'll be the ones making the tackle while everyone else engages blockers. Every DB in the NFL obviously can tackle, but it must just come down to how much they want it and how much they believe it will help. The Patriots pretty much always have a top 5 tackling secondary I think, even when they had players like Pat Chung who used to get criticised for being a liability in coverage.