Sparano said during his Feb. 7 press conference he wanted to use a system that was best suited to the team's personnel, but one of the biggest moves made in the offseason was geared toward the Dolphins using the 3-4.
The most obvious was the trade for Dallas defensive tackle Jason Ferguson, who played nose tackle for Parcells with the Jets and the Cowboys before he sustained a torn biceps tendon in last season's opener.
Ferguson can play in a 4-3 defense, but his best role clearly is as a 3-4 nose tackle.
Another indication the Dolphins will play a 3-4 is that one defensive assistant coach they sent to Chris Long's Pro Day at Virginia was outside linebackers coach Jim Reid and not defensive line coach Kacy Rodgers.
Long played defensive end in college and looks like a sure thing at that position in the NFL, so maybe the Dolphins were just doing their due diligence by checking him out at linebacker.
But then there's the major pursuit of free agent Calvin Pace from Arizona. Pace was a former first-round pick who did nothing as a defensive end in his first three seasons before blossoming as a 3-4 outside linebacker in 2007.
Pace eventually signed a six-year, $42 million contract with the Jets, and the Dolphins were believed to have offered him a similar deal. Let's face it, neither the Jets nor the Dolphins were going to spend huge money on Pace based on what he did as a defensive end.
He will play outside linebacker in the Jets' 3-4, and that's just where he would have played with the Dolphins.
The Dolphins played mostly a 4-3 last season after using a combination 3-4/4-3 under Nick Saban. It's pretty clear the Dolphins did a lot better in the Saban defense, although there were several factors involved beyond the mere defensive alignment.
Jason Taylor, for example, thrived at the "Jack" linebacker position in Saban's defense, earning NFL Defensive Player of the Year in 2006 in that role. Joey Porter also was a Pro Bowl player in Pittsburgh in the Steelers' 3-4, but it took him a while to become productive with the Dolphins last season.
As things stand now, the Dolphins pretty much have the pieces in place in the front seven to play a 3-4, except perhaps for a defensive end to line up opposite Vonnie Holliday.
Kevin Carter was very good in that role in 2005 and 2006, but he was let go by Cam Cameron last offseason and ended up with Tampa Bay.
The Dolphins need another defensive end with that kind of size, and Matt Roth -- last year's starting DE opposite Jason Taylor -- doesn't have it. Neither does Chris Long, which is why he probably would be switched to outside linebacker should the Dolphins make the No. 1 overall pick.
What the Dolphins will do with that first overall pick is one of the many mysteries surrounding the team. What defense they will use really isn't.