With the NFL Draft and free agency having come and gone, we’ll break down all sorts of fantasy-relevant questions entering the 2018 season. Up next is a look at the Philadelphia Eagles’ new unquestioned lead back using the Rushing Expectation methodology.
The Dolphins’ struggles running the ball in 2017 are well documented. Miami finished 30th in Adjusted Line Yards, per Football Outsiders, with their 3.26 mark in the 2nd percentile overall since 2000. After managing 3.4 yards per carry through his first seven games, Jay Ajayi seemingly took the brunt of the blame and was shipped him to the Eagles for a measly fourth-round pick — a trade that ended up with Ajayi wearing a Super Bowl ring.
In both real life and DFS, Ajayi was far better able to meet expectations with the Eagles. Per our NFL Trends tool, Ajayi hit value on DraftKings in 44% of games with Philadelphia but only 28% of games with Miami.
What changed for Ajayi in Philadelphia, and what does it mean for 2018?
Note: If you’re not familiar with Rushing Expectation, watch the video below for a brief intro.
The largest discrepancy in Ajayi’s rushing usage between Miami and Philadelphia was between the tackles. In Miami, he most often ran straight up the middle and rarely to the outside.
The Eagles put a much larger emphasis on getting Ajayi to the edge to turn the corner, usually on tosses, sweeps, or stretch plays.
Neither Miami or Philadelphia utilized Ajayi in the passing game much. He averaged only 2.0 targets per game with Miami and 1.4 with Philadelphia, though the Eagles gave him a slight bump with eight targets over their first two playoff games before failing to look his way in the Super Bowl.
The sample size in the passing game is very small — far outside the scope of my typical sample size — but one conclusion that can be drawn is the Eagles were more comfortable giving Ajayi targets behind the line of scrimmage and letting him create in space.
Expectation Score is the signature metric of Rushing Expectation and highlights the fact that not every Success Rate is created equal. Expectation Score is a running back’s actual Success Rate divided by his Expected Success Rate. A number higher than 1.0 means he performed above expectation relative to blocking, and a number lower than 1.0 means he performed below expectation relative to blocking.
In Miami, Ajayi performed well above expectation behind struggling center Mike Pouncey, who was counted on too heavily in the run game. Ja’Wuan James was probably the team’s top lineman, so it makes sense that Ajayi ran off right tackle at an above-average rate, though he didn’t do much with those carries. Outside of James, the entire Dolphins O-line from 2017 was ugly:
- LT Laremy Tunsil, ranked No. 77 of 83 qualified tackles in run blocking by Pro Football Focus (90.07% snap rate)
- LG Jermon Bushrod, No. 63 of 80 (58.24%), Ted Larsen, No. 69 of 80 (50.24%)
- C Mike Pouncey, No. 33 of 38 (93.64%)
- RG Jesse Davis, No. 62 of 80 (72.03%)
- RT Ja’Wuan James, No. 42 of 83 (47.64%)
Ajayi’s most efficient running lane overall tends to be off left tackle, though Tunsil in Miami, and later, Halapoulivaati Vaitai in Philadelphia, were both below average last season. In fact, if there was a weak link in the spectacular Eagles line, it was Vaitai:
- LT Halapoulivaati Vaitai, No. 62 of 83, (73.3%)
- LG Stefen Wisniewski, No. 12 of 80 (61.6%)
- C Jason Kelce, No. 1 of 38 (95.4%)
- RG Brandon Brooks, No. 4 of 80 (95.2%)
- RT Lane Johnson, No. 16 of 83 (85.2%)
Despite Vaitai’s poor overall grade, he improved down the stretch, and along with Johnson, accounted for Ajayi’s most efficient running lanes (off tackle).
What’s most peculiar about Ajayi’s rushing usage with Philadelphia was that despite their biggest advantage being Kelce at center, Ajayi saw a sharp decline in attempts straight up the gut. Eagles coaches may have been onto something; unlike in Miami, where Ajayi tended to gain more yardage than his center Pouncey blocked, he performed well below expectation when running up the middle in Philadelphia.
The Eagles are expected to bring back all their starters up front this season. Jason Peters (No. 19 of 83) is on track to return to the left tackle spot in place of Vaitai after suffering a season-ending knee injury before Ajayi’s arrival. That could certainly bode well for Ajayi moving forward if Philly plans to continue to try and get him to the edge. However, Ajayi also has to be better about not bouncing runs outside — a bad a habit he also had early in his career and in college — in order to better take advantage of Kelce’s stellar interior blocking at center.
Despite limited help from his blocking in Miami, Ajayi actually performed higher above expectation as a runner there than in Philadelphia after adjusting for O-line quality:
- Ajayi’s rushing Success Rate was below the league average on both teams, but he actually performed above expectation after adjusting for his offensive line in Miami, and right at league average after adjusting for offensive line in Philly. This shows how much O-line matters: Even performing at just a league-average rate behind the Eagles’ O-line allowed him to gain 5.8 yards per carry — 2.4 more than he averaged with Miami.
- Ajayi was stuffed at or behind the line of scrimmage far more often with the Dolphins, and his average time behind the line decreased dramatically with the Eagles.
- Philly’s line surprisingly comes in as below average in terms of Adjusted Line Yards (which I weigh heavily in my expectation metrics). How is that possible? Adjusted Line Yards is not a pure offensive-line grade, it’s a metric that assigns a certain amount of responsibility to the offensive line for every rush based on the length of that rush. For example, the offensive line is given most of the responsibility on short runs close to the line of scrimmage, but doesn’t get as much credit for yardage gained by the running back further downfield. Given that the Eagles line graded well in PFF and also had a high Expected Success Rate, the most likely explanation is that the coaching staff emphasizes getting off blocks at the first level quickly to spring backs for chunk plays at the second level. (The Eagles came in as one of the top lines in terms of Adjusted Reception Yards, a comparable metric to ALY that I created to mirror the offensive lines impact on the receiving game for the running back position.)
- Despite seeing a slight bump in targets in Philadelphia’s first two playoff games, Ajayi struggled as a receiver.
Ajayi is intense, aggressive, and runs with reckless abandon at times. He stands out at the second level, and he knows how to create big play. Behind the Eagles offensive line, Ajayi should be able to build on his highly efficient second half of 2017, and even modest improvement as a pass catcher could increase his upside even more. He’s a strong RB2 pick with RB1 upside.
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Pictured above: Jay Ajayi
Photo credit: Matthew Emmons – USA TODAY Sports