In the famed "West Coast" Offense that was made famous by the late Bill Walsh, it was and still is about exploiting "match up" problems. Walsh would change his game plan each week to find "mis-matches" for each team and make his game plan accordingly.
Let's look at one matchup that is still available for most teams and why it is still there. The Tight End. When you look at how most all Defenses are built as far as the size and strength of the players at each position you will see why they are the way they are.
We will start with the Defensive Linemen. They are usually the biggest guys on a defense because they have to matchup with the big guys on the Offensive Line. The 3 or 4 guys on the Defensive Line are usually around 6'-6'5" and 280-340 lbs because they have to be able to take on the Offensive Linemen who are of similar size.
Next, the Linebackers. They have to be able to be big enough to handle any O-linemen that shed their initial block and try to pancake the linebackers, yet fast enough to go side to side and handle both the big running backs as well as the smaller and faster running backs.
And then finally the Defensive Backs. In a normal base defense, there are normally 2 Corners, and 2 Safeties and they need to be around 6 feet and 200 lbs with enough speed to handle the wide receivers. Green Bay played a lot of 3 Cornerbacks last year because of so many teams going with a "spread" formation of 3 wide receivers as part of their base offense.
So, you can see that the Lines on both sides match up. The RB's match up with the LB's and the WR's match up with the Corners and Safeties, but this leaves us with the Tight Ends. The Tight Ends are usually too big for corners or safeties to matchup with and too fast for the Linebackers to matchup with and that is one reason that the Patriots are having such success with their really good pair of Tight Ends and why we see so much of their 2 Tight End offense.