What does this strange, new metric say about Rams receivers?

I recently came across an interesting and cheeky (literally) new metric that may be of use to project future receiving production and identify fantasy football sleepers. At first, I couldn’t believe the name, Average Separation Score (ASS) and thought I was reading satire from something like The Onion or The Babylon Bee.

But upon further review, and after reading a lengthy but worthwhile read on the metric, I think this is something worth keeping an eye on. At the very least there were some interesting takeaways as it relates back to the pass catching corps for the Los Angeles Rams.

What is ASS?

This article by Fantasy Points goes into a deep dive on ASS.

The bottom line is that this metric is an attempt to measure and evaluate wide receiver performance independent from quarterback play and whether they were targeted. ASS measures the amount of separation created when running routes and can provide specific data based on coverage type, route concept, and more.

One of the most important aspects of advanced metrics is that they allow for better predictability versus traditional volume-based statistics like receiving yards, receptions, touchdowns, drops, etc. ASS ignores coverage busts because they are outside the control or effect of a single receiver, and it attempts to isolate individual performance from the the rest of the offense.

ASS suggests a breakout for Demarcus Robinson

In a post on fantasy football sleepers, Demarcus Robinson makes the list as someone who is a consistent separator. Here’s what Fantasy Point had to say:

Robinson ranked 18th of 125 qualifying WRs in average separation score last year (0.167). The year before that, he ranked 15th of 117 qualifiers (0.210). But maybe we shouldn’t be too surprised.

Robinson went on a tear at the tail-end of last season. After finally supplanting Tutu Atwell as the Rams’ full-time WR3 in Week 14, Robinson scored double-digit fantasy points (half-point PPR) in each of his last five games. Over this span, he averaged 6.8 targets per game (~WR27) and 15.6 FPG (~WR17) on an 80% route share. He represents a terrific value in best-ball leagues priced as the WR78, playing for a Rams offense that routinely leads the league in usage of 3WR sets.

With Puka Nacua working his way back from a knee injury he suffered in training camp and Cooper Kupp being susceptible to injuries in recent seasons, the Rams could easily find themselves in a position where they are heavily relying on Robinson. His separation score also explains why he pulled ahead of Tutu Atwell on the depth chart towards the end of last year.

Puka Nacua knows his role in Rams offense

Nacua’s surprise success as a rookie in part was a product of finding himself in a great situation at the right time. Kupp was injured to start the 2023 season and he’s declined in his ability to win on in-breaking routes (this is described below). Matthew Stafford is great at throwing in-breaking routes, and Sean McVay will dial them up often. These stars aligned for what became the most productive rookie receiving season in NFL history:

Last year, 19.3% of Puka Nacua’s route tree was made up of in routes (3rd-most of all players), on which he averaged a 0.28 separation score (12th-best). Cooper Kupp averaged just a -0.09 separation score on these routes (7th-worst among 125 qualifying WRs/TEs). Matthew Stafford targeted a receiver running an in route a league-high 53 times in 2023, the same number as in 2021 and 2022 combined. I’m not sure what this means for the Kupp vs. Nacua debate in 2024, but it is evidence Stafford (and Sean McVay) tailored the offense to the strengths of their best healthy receiver, a skill Stafford might particularly excel at.

Kupp, Nacua make list for negative outliers

“Why doesn’t [superstar WR] have an amazing ASS?”

While Robinson ranked 18th of 125 qualifying receivers in ASS, Nacua and Kupp were further down the list than you’d expect at 38th and 46th, respectively.

Fantasy Points suggests that Nacua may not be quite at the superstar level yet and was possibly a product of the system and being a perfect match with his quarterback, which is probably fair and could help explain why a late fifth round pick was able to be so productive as a rookie

Why did Puka Nacua (38th) and Cooper Kupp (46th) post underwhelming average separation scores? Kupp’s injury aside (he ranked top-20 in 2022), Nacua’s stylistic fit with Matthew Stafford is likely a factor. According to one of our charters, “I think on teams with a QB like Stafford and a condensed offense like LA that isn’t afraid to thread the needle, being a more physical, strong-handed receiver who separates less isn’t as much of a detriment.” As discussed above, Stafford has always been a miracle worker at elevating WR production and seems excellent at playing to the strengths of his receivers.

To sum up this section, separation is not the only way a WR can succeed. It is a big part of the position and a great place to start with an evaluation, but players can and do reach superstar status via overwhelming excellence in other traits. If a player is hyper-productive without great separation, it’s likely he’s doing something else very right.