In the first three years of his young NFL career, Miami Dolphins cornerback Sean Smith performed well below the expectations that came when he was selected in the second round of the 2009 draft. The standout cornerback out of Utah put up mediocre numbers to say the least as he recorded 152 combined tackles and three interceptions while not being able to produce a single quarterback sack or forced fumble. Prior to the start of the Dolphins 2011 campaign, Vontae Davis went out on a limb and claimed that the duo of Smith and himself was the best cornerback tandem in the league. As we all know, Vontae Davis was dealt to the Colts following a disappointing training camp this past August leaving Sean Smith with the responsibility of covering the opposing teams' top wide recievers.Five weeks into the 2012 season, it is evident that Sean Smith has turned a corner in his career and is developing into an elite cornerback. Smith's drastic improvements are in large part due to the fact that he is finally being utilized correctly in new defensive cordinator Kevin Coyle's system. As it turns out, Coyle was very fond of Smith in his days with the Cincinnati Bengals and targeted the 6 foot 3, 218 pound defensive back in the 2009 draft. He was intrigued by Smith's great leverage, great length and speed however the team opted to look elsewhere with the 38th overall pick.Coyle has played Smith to his strengths rather than his weaknesses and has ensured the 25 year old be put in a position to succeed. It's the small details that have made a difference such as utilizing his height to his advantage and attacking the ball at its highest point. Not only has Smith's play improved, his confidence has done the same as he has insisted on covering pro bowl wide recievers Larry Fitgerald and AJ Green in Miami's past two games. In Arizona, Smith held Fitzgerald to eight catches for 64 yards along with producing two interceptions. He followed that up by holding Green to 65 yards on nine catches in arguably the best game of his career a week ago.Smith's success against these wideouts have him ranked as the 16th best cornerback in the league by Pro Football Focus. When throwing in Smith's direction, quarterbacks have only managed to complete 47.8 percent of their passes which stacks up as 14th in the NFL. The 66.5 quarterback rating he has surrendered is 21st among players at his position. Although Smith has impressed through five games, the Dolphins pass defense as a unit has been less than spectacular. In the team's first four matches, their pass defense ranked 30th in the league while allowing 297.8 yards a game through the air. For the first time all year, the entire defense played significantly well as a whole in the win against the Bengals. Both Nolan Carroll and Reshad Jones stepped up with key performances including a game sealing interception from Jones in the last minute of the fourth quarter. The unit's improved play has resulted in a 4 spot increase to their overall ranking to 26th in the league along with their 54.7 opponents completion percentage which ranks third. With CB Richard Marshall ruled out for Sunday, the Dolphins secondary will have to come up big once again in order for Miami to improve their record to 3-3 heading into the bye. Sean Smith looks to be in the midst of a breakout season and if he continues to record stellar numbers, he may find himself playing in his first pro bowl. With Smith in a contract year, the Dolphins have some tough decisions to make about the cornerback's future in Miami.