Miami has given up the fewest yards per play of any team in the NFL (4.68) and they are tied for second in takeaways with 18. Essentially, it's a sound defense that still makes a ton of big plays.
Consider the last three weeks. The Dolphins dominated the Bears' offense in Chicago, giving up only 13 points. Miami's defense scored more points (14) than they gave up against Jacksonville (13). Last week, the Dolphins notched a shutout against Philip Rivers, one of the top quarterbacks in football.
Miami's defense starts with the best pass-rushing duo east of Denver. Cameron Wake has been a top-three player at his position for years, and hasn't slowed down. Olivier Vernon is backing up his breakout 2013 campaign with even better play this season. It was almost comical how many times Wake and Vernon "met at the quarterback" against San Diego.
The Dolphins defensive line is impressive because of its depth. Last year's No. 3 overall pick Dion Jordan will be getting into the mix more after coming off a suspension. Jared Odrick and Randy Starks push the pocket and stop the run. Defensive tackle Earl Mitchell has proven to be a terrific free-agent signing.
Move past the line, and you have an emerging star at linebacker in Jelani Jenkins. Cornerback Brent Grimes is incredible at jump balls despite his size, and safety Reshad Jones is one of the most versatile players at his position. Even fifth-year linebacker Koa Misi, usually a bit player, made some splash plays against San Diego.
Defenses are tougher to predict annually than offenses. Like a major league bullpen or an NFL offensive line, there is something undefinable about what makes defenses excel. Miami clearly has enough talent, and the Dolphins now look like a group that is feeding off one other. They look like a group that knows they can be great.