Photo: Jeremy Brevard, USA Today Sports

Possibly the biggest fantasy shift this offseason has been the trade of D.J. Moore to Chicago. The fantasy community has longed for Moore to get improved quarterback play and unlock his high-end potential. Has this finally happened with the pairing of Moore and Justin Fields?

This prior article closely examines vital wide-receiver metrics like Targets Per Route Run and Yards Per Route Run. You'll want to check it out before continuing here.

Where Targets Come From

Three factors determine a wide receiver’s targets:

• His team’s passing dropbacks.
• The percentage of those dropbacks he runs a route (route participation).
• The percentage of the routes he is targeted on (TPRR).

To increase a player’s targets, he either needs an increase in team dropbacks, route participation, or the percentage of the routes he is targeted on. When one goes down, you need another to go up to maintain a similar target volume.

D.J. Moore has been a nearly every-down player in his career and has been targeted on 21.8% of his routes.

This is an 89th-percentile career performance. In his career, D.J. Moore has had 1.94 yards per route run, a 92nd-percentile career performance.

Moore could see small increases in route participation or take a jump in TPRR, but expecting a major leap in year six of his career is overly optimistic.

If Moore is going to increase his fantasy football scoring, he needs an increase in volume or an increase in the less predictable efficiency of the targets. Throughout much of Moore’s career, there has been quarterback uncertainty, which has trickled into the team’s fantasy football production. Below is a chart of the passing game efficiencies for the Carolina Panthers since D.J. Moore was drafted in 2018.

Overall, the team has been a bottom 25% passing team for most of the past four years in terms of points per passing attempt and points per passing dropback. However, the team has fluctuated in its dropback rank. They have been a top-half-of-the-league in dropbacks in 2018, 2019, and 2020 but fell to the bottom in 2022.

Many are pointing to the bad quarterbacks, evidenced by the low points per passing attempt, as the argument for Justin Fields elevating D.J. Moore. In fact, Chicago has been better per attempt than Carolina in the past two years. In the past two seasons, Chicago has ranked 28th and 17th in points per attempt, a positive sign many are hoping for.

However, all other passing ingredients have been problems. The team plummeted in dropbacks rank from 15th in 2021 to 31st in 2022. The team has ranked 31st and 32nd in points per dropback the past two seasons (0.81 PPR points per dropback each season).

The Lost Dropback

How does Justin Fields have such bad per-dropback efficiency while improving in points per attempt scoring in 2022? The explanation is the Lost Dropback.

When a quarterback dropbacks back to pass, there are three outcomes: a passing attempt, sack, or scramble. The sacks and scrambles that do not result in a passing attempt are combined into a Lost Dropback Rate.

Fields has the highest Lost Dropback Rate percentage of any quarterbacks in the past two seasons. In 2021, 23% of Field’s dropbacks were lost, and this jumped to 28.2% in 2022. Fields has lost 25.9% of his dropbacks in his career, the most in the league for any quarterback with 500 dropbacks since 2008 by a wide margin.

The next closes quarterbacks since 2008 in Lost Dropback Rate are:

• Tyrod Taylor 18%
• Michael Vick 17.8%
• Colin Kaepernick 17.1%
• Deshaun Watson 17%

Fields has had an enormous effect on the Chicago offense. From a fantasy football perspective, he has the capability to be a dominant runner, which can support his own fantasy production. However, his Lost Dropback Rate will clip the fantasy prospects of his supporting cast unless his volume changes.

In 2022, Carolina ran 56.9 plays per game, which ranked 31st in the league, ranked only ahead of Chicago, which ran 54.1 plays per game. Carolina called designed passes on 54.1% of plays, the 30th highest rate in the league, while Chicago called designed passes on 55.4% of plays, the 27th highest rate. Both offenses are low-volume, run-heavy offenses that are not great for receiving points.

Overall, in 2022 Carolina dropped back to pass 30.8 times per game, just ahead of Chicago, which dropped back to pass 29.9 times per game in 2022. These teams only ranked ahead of Atlanta in dropback volume in 2022.

While they are close in plays, dropbacks, and dropback rate, you see the impact of the Lost Dropback Rate because Carolina threw 26.9 attempts per game compared to only 22.1 by Chicago.

The effect of this is big for Moore. If Moore maintained the 25.7% target share he had in Carolina in 2022 with the passing attempt volume Chicago had in 2022, Moore would drop from 118 to 97 targets.

Justin Fields' Play Style

D.J. Moore’s move from Carolina to Chicago has been lauded as helpful for his fantasy prospects, but Field’s style of play is a major red flag.

The biggest defense for Fields throughout his career has been his poor supporting cast. For example, much of the defense of Justin Fields’s scramble rate is attributed to Chicago’s offensive line struggle and lack of offensive weapons.

This can be tested in terms of publicly available offensive line data. For example, ESPN publishes Pass Block Win Rate data, which “conveys the rate linemen can sustain their blocks for 2.5 seconds or longer.”

Overall, Chicago (68%) ranked second, behind only Kansas City (75%) in Pass Block Win Rate.

When you plot team Lost Drop Back against ESPN Pass Block Win Rate, you see little correlation.

Overall, there is an r-squared of only 0.0716 between the pass block win rate and Lost Dropback Rate, meaning the pass block win rate explained only 7.1% of a team’s Lost Dropback Rate.

This is a major indication that Lost Dropback Rate is a quarterback stat. Indeed, Lost Dropbacks Rate is a product scramble rate and sack rate, which are both highly correlated year over year.

The below graph shows the scramble rate or the percentage of quarterback dropbacks where he scrambled instead of attempting a pass. The graph compares a quarterback’s scramble rate (horizontal axis) and his scramble rate the following season (vertical access).

Overall, there is an r-squared of .688, meaning a season’s scramble rate explains 68.8% of the quarterback’s following season's scramble rate.

This is logically straightforward. Pocket passers like Tom Brady scramble at a low rate and are unlikely to change. Likewise, quarterbacks who are runners tend to stay as runners.

The sack rate is also correlated year over year, but less so than the scramble rate.

Overall, there is an r-squared of 0.196 between sack rate and sack rate the following season meaning a quarterback’s sack rate explains 19.6% of his sack rate the following season. The lower correlation between years is a function of variance and the impact of the team’s changing landscape, including different supporting casts, schemes, and offensive lines, can have on a sack rate.

The below graph shows the Lost Dropback Rate for quarterbacks in back-to-back seasons.

Overall, Lost Dropback Rate has an r-squared of 0.605, meaning a quarterback’s Lost Dropback Rate explains 60.5% of his Lost Dropback Rate of the following season.

Quarterbacks can help wide receivers in two different ways on their dropbacks. First is the quality of the attempts the quarterback throws. For example, a throw from Patrick Mahomes II is more valuable than a throw from Zach Wilson. Much of our conversation around wide receivers centers here. Moore’s quarterback has been a disappointment during his career, so an upgrade of a quarterback will increase his efficiency and should show up in the points-per-attempt numbers.

The second less discussed way is the percentage of dropbacks a quarterback actually throws a passing attempt. The Lost Dropback Rate creates a massive problem for wide receivers because it eliminates a passing attempt on a dropback where a wide receiver can be targeted.

Much of the support for Fields will point out the weak supporting cast of his passing game targets in his first two seasons. Some would argue that Moore should reduce Fields' Lost Dropback Rate because Moore will be open more often than the wide receivers Fields has thrown to in his career.

Recent history has shown an upgrade in wide receiver has little, if any, effect on the quarterback. For example, Josh Allen (Stefon Diggs), Joe Burrow (Ja’Marr Chase), Tua Tagovailoa (Tyreek Hill), and Jalen Hurts (A.J. Brown) have all added an elite wide receiver in recent years. While there have been improvements, the results are mixed.

• Allen added Diggs and fell from 15.4% to 8.9%.
• Burrow added Chase and increased from 10.6% to 12.2%.
• Tagovailoa added Hill and fell from 9.4% to 7.2%.
• Hurts added Brown and increased from 14.7% to 14.8%.

The two big improvements were Allen and Tagovailoa, while Burrow and Hurts (barely) both had higher rates, so Moore's addition is hardly a guarantee to improve Fields's Lost Dropback Rate.

The other argument in support of Fields is that the team’s offensive line did not allow Fields to succeed, but it is difficult to evaluate considering the length of time Fields takes to make throws, which has been true since college.

Instead, there is a strong reality that Fields is a lost dropback generator. For example, his college offense featured Chris Olave, Garrett Wilson, and Jaxon Smith-Njigba, but Fields still had a career Lost Dropback Rate of 18.9%, which ranks in the 94th percentile among college quarterbacks.

In other words, the best core of offensive passing game targets Fields will ever have, did not keep Fields from scrambling and getting sacked at an extremely high rate.

Takeaways

Justin Fields is a potentially elite fantasy player in his own right, but he will be a drag on his supporting cast unless he has a massive change in play style. In order to maintain the same targets based on Chicago’s 2022 volume, Moore would need to be targeted on 31.8% of Chicago’s attempts, which would have led the league in target rate in 2022.

For Moore to live up to his lofty expectations, he will need the team to run more plays and drop back to pass at a higher rate and for Fields to improve his Lost Dropback Rate. For example, even if you gave Chicago the most dropbacks in the league from 2022 (776 by Tampa Bay) and applied Fields’s Lost Dropback Rate (28.2%) and Moore’s 25.7% target share, that would give him 143 targets, which would have ranked 10th in the league in 2022.

There is much optimism among fantasy GMs about Moore’s move to Chicago, with 41% saying the trade increased his dynasty value compared to only 22.2% who said it decreased his valuation.

Moore is a very good wide receiver, but he is being dropped into a situation unlikely to amplify his fantasy productivity. Based on this trade news, there is plenty of time and opportunity to sell him at a profit and move for another wide receiver with a higher volume projection.