The Numbers Behind the Miami Dolphins' Struggles
This is not how things were supposed to go for the Dolphins this season.
After a solid 2014 that saw them go 8-8 and finish 13th in our nERD rankings, Miami seemed like a solid bet to take the next step and challenge for a playoff berth this year.
While we are just four games into the season, things could not have deviated from this script much further.
The Dolphins are 1-3, with their only victory coming in an unconvincing, special teams-driven 17-10 win against Washington in Week 1. Miami then fell to Jacksonville, 23-20, before getting crushed by Buffalo, 41-14, in Week 3.
Last week in London, they got beat by the Jets, 27-14, in a game that probably wasnâ€™t even as close as the final score indicated. The loss also marked Joe Philbinâ€™s final game as Dolphins head coach, as he was fired and gave way to tight ends coach Dan Campbell on an interim basis.
By our nERD ratings, the Dolphins rank 26th, and would be expected to lose to a league-average opponent by about 4.4 points on a neutral field.
They have been outscored by 36 points, and their average scoring margin of -9.0 points per game is fifth worst in the NFL, as they have struggled on both sides of the ball.
Offense Takes a Step Back
There was a lot to like about the Dolphins offense last season, as it ranked 12th in Adjusted Net Expected Points (NEP) per play, which compares a team's performance to expectation-level.
It was not a sexy unit but an efficient one nonetheless and was one that was more methodical than explosive.
Despite tying for 14th in yards per play, Miami was seventh in drive success rate (the percentage of series that result in a first down or touchdown), according to Football Outsiders.
Quarterback Ryan Tannehill epitomized this efficiency-over-explosiveness approach, as although he ranked 21st in Passing NEP per play last season, he was seventh in Success Rate (among quarterbacks who attempted at least 50 drop backs; success rate is the percentage of plays that gain positive expected points).
This has not been the case so far this year, however, as Tannehill ranks 33rd out of 35 quarterbacks in Success Rate and 32nd in Passing NEP per drop back.
The Texas A&M product has seen his completion percentage drop from 66.4% last year to 56.7% this year and is also throwing fewer touchdowns per pass and more interceptions per pass (though these stats are probably too volatile to judge this early in a season).
Tannehill has also been less of a factor with his legs. After producing 13.42 Rushing NEP on 41 carries last season, he has ran the ball only 6 times for -0.16 Rushing NEP this year.
He is not the only Dolphin to see his rushing efficiency decline from last season, either.
After ranking fifth in Adjusted Rushing NEP per play last season, Miami is 18th this year.
Lamar Miller was seventh in Rushing NEP last season, and was fifth in Success Rate among running backs with at least 50 carries (46.98%).
Miller is now 18th among running backs with at least 20 carries in Success Rate this season (43.24%) but has yielded -3.37 Rushing NEP.
The problem has been negative plays and a lack of big ones. While Miami has had only 16 runs get stopped for no gain (only two teams have fewer), these plays have lost an average of 1.1 yards, right around the league average of 1.2.
The Dolphins also have only 9 runs that have gained 10 or more yards, and only 6 teams have fewer.
On these runs, Miami has gained an average of 13.4 yards per carry. This ranks 29th in the league, and the NFL average is 15.9.
Struggles Against the Pass
Miamiâ€™s defense has hardly made things better.
The Dolphins rank 27th in Adjusted Defensive NEP per play, and its pass defense has been the biggest problem.
Miami is 31st in Adjusted Defensive Passing NEP per pass and ranks 29th in net yards allowed per pass.
The problems here start up front, where the Dolphins have gotten just one sack on 123 drop backs, giving them a league-worst 0.8% sack rate.
They have also notched just 12 hurries, according to SportingCharts.com, as the high-profile players in their front seven have yet to make an impact rushing the passer.
The secondary has struggled as well. While Brent Grimes has held his own, his teammates in the defensive backfield -- Jamar Taylor and Brice McCain and safeties Reshad Jones and Walt Aikens -- have not.
Miami has been comparatively better against the run, ranking 18th in Adjusted Defensive Rushing NEP per play, despite allowing 4.4 yards per carry (tied for 25th).
Their opponents have only gained positive expected points on 40.8% of their rushes, giving the Dolphins a rush defense success rate that would have ranked 13th last season.
Overall, the run defense has been efficient but also susceptible to big plays, as Miami has allowed 18 runs of 10-yards or more to tie with the Buccaneers for the most in the league. This explains the disparity between Miamiâ€™s defensive success rate against the run and rushing average allowed.
Philbin seemed to be doing a poor job this year, but there is no evidence Campbell can improve things drastically. Even if he can, though, the Dolphins may have already dug themselves into too deep of a hole for it to matter, as we only give them a 5.5% chance to make the playoffs.