Pro Football Focus will be providing analysis for every major NFL signing and trade during the 2015 free-agency period, accounting primarily for the quality of the player and his fit with his new team, and focusing less on the financial terms of the deal.
Here is a grade for the trade between the Miami Dolphins and New Orleans Saints.
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Dolphins get: WR Kenny Stills
Saints get: LB Dannell Ellerbe, third-round pick

Miami Dolphins: B-plus
At his cap hit, the Dolphins were likely going to cut Ellerbe, so for them it is somewhat like they used their 2015 third-round pick on Stills. While he will need to get paid sooner than a rookie would, he's still much better than a player a team would typically get in the third round.
Stills was the wide receiver with the best catch rate on deep passes (20-plus yards in the air) in 2014, catching nine passes on 14 targets for 370 yards and two touchdowns. Typically a player will have either a high catch rate if he catches short passes, or a high yards per catch because of grabbing deep passes. Stills had both at a 78.8 percent catch rate and averaged 14.8 yards per catch.
The Dolphins now have the potential to be one of the best passing offenses in the league. Quarterback Ryan Tannehill has played well in his first few years in the league, and now has the weapons of Mike Wallace (if he remains with Miami) and Stills as his outside receivers, Jarvis Landry in the slot and Jordan Cameron at tight end.

New Orleans Saints: C-plus
The good part of the trade is the third-round pick. The Saints are trying to build a strong defense through the draft at the expense of the pass offense. New Orleans now has five picks in the first three rounds of the 2015 draft, but it came at the expense of Drew Brees' best two receivers in 2014. These trades can pay off for the Saints, but by the time they do, someone other than Brees might be at quarterback.
As for Ellerbe, while he can be good in coverage, his run defense rating of minus-15.4 was third-worst for inside/middle linebackers in 2013. He then played just 18 snaps of 2014 before his season-ending hip injury. Even with a restructured contract, the Saints would have been better off just trading Stills for a third, and then signing one of the linebackers left on the free-agent market.