When the Chiefs signed Eric Winston, I was very excited. Right tackle was the weakest position on the team in 2011, while Eric Winston was one of the best in the league for the past several years. It is very rare to go from one of the worst to one of the best at a position in a single offseason. However, how much does this upgrade really matter? Does the right tackle really have a big enough effect on the offense to warrant excitement, even with the significant upgrade?
In general, this question depends on context. Not just on the context of the player he's replacing, but the context of the line as a whole. To understand what the context is and why it matters, you have to look at position groups in an unusual way.
The idea is simple. The offensive line is like a chain. It doesn't matter how strong the links in the chain are if one of the links is weak. When the chain is force to contain a force, the weakest link breaks and the chain fails. Similarly, the offensive line is only as good as it's weakest member, since it doesn't matter if everybody else is dominating their guy, if one lineman lets a rusher get by him, the quarterback is sacked.
This is very different from other position groups. Receivers, for example, are the opposite of this. One extremely weak receiver doesn't matter as long as you have another great one. If Dwayne Bowe was playing in a high school team, you could have a bunch of computer geeks as the other receivers and your passing game would still dominate.
Since the defensive line plays against the offensive line, they are of the opposite type and therefore more like receivers in that having one or two stars is more important than every one being good. Defensive backs, on the other hand, are like offensive linemen, where one bad player can kill you.
This makes a huge difference on how you want to build a team. For the offensive line and defensive backfield, having a star player isn't so important. What you should be concentrating on is the weakest link, since that determines how good that group is. For the defensive line and receivers, bad players are tolerable as long as you have a superstar or two.
It is because of this that the Eric Winston signing is so exciting. With Richardson, our weakest link was very bad, which meant that our line was far worse than it should have been. With Winston in that spot, right tackle is no longer our weakest link. That weakest link is probably Lilja. So when thinking about the Winston signing, it is better to think about it as upgrading our weakest link from Richardson to Lilja rather than upgrading that spot from Richardson to Winston.
(Thanks to Advanced NFL Stats for giving me inspiration for this post. I would have never came up with this without them.)