So many times I have found myself researching players and going through the same cycle. How many rush attempts did RB “x” have? How many targets? Were they near the red zone? How many were by the goal line? How does all this compare to the rest of the league? As you can imagine, it’s very easy to get lost in the numbers and before you know it you’re sitting there with tabs so small you have no idea which one has your latest Pro Football Reference query or that latest awesome Gridiron Experts article posted by George Fitopoulos (shameless plug).
Well, I’m here to introduce you to a neat metric that packages up all these questions into an all-in-one statistic — Welcome to Opportunity Index (OI).
When it comes to fantasy football, opportunity is king. The more opportunities a football player gets to make plays on the field, the more fantasy points he should score for your fantasy team. Well, theoretically at least. Jody Smith did a great job with a deep-dive into red zone targets this offseason for both the AFC and NFC teams, which you should definitely check out.
So how exactly do we measure opportunity? Well, for quarterbacks it’s measured in both pass attempts and completions plus rush attempts while for the skill positions it’s rush attempts plus receiving targets. Seems pretty simple, right? None of this is ground-breaking stuff, but unlike that one famous line from the Declaration of Independence, “All men are created equal,” opportunities aren’t men, and they certainly aren’t created equal. Yes, I just quoted the Declaration of Independence in a fantasy football article.
In the simplest of terms, OI is weighted opportunity. It measures the quantity, but more importantly it also measures the quality of opportunity on a per-snap basis. Each player’s output is then compared to the league average over the last four seasons, and the output is a metric that will tell you how much better or worse that player’s opportunity is than the league average.
To measure the quality of an opportunity, I take a look at where the line of scrimmage was when it occurred. Obviously, the further away a player’s opportunity occurs from their own goal line the more valuable it is, but in case you don’t believe me here’s a chart:
While the x-axis is hard to read — trust me — it goes from one to ninety-nine (nearest to own goal to furthest to own goal).
For each position, the average fantasy points per play travels in a rather flat line until the red zone area. From there we see a small spike and then a couple of steeper spikes within the final 10 yards. Overall, I identified seven areas to use as the meat of my OI analysis.
- Non-Red Zone: Anything that occurs outside the red zone.
- Red Zone: Between the opponent’s 11 and 20-yard line.
- Goal Line 1: Either on the opponent’s nine or 10-yard line.
- Goal Line 2: Either on the opponent’s seven or eight-yard line.
- Goal Line 3: Either on the opponent’s five or six-yard line.
- Goal Line 4: Either on the opponent’s three or four-yard line.
- Goal Line 5: Either on the opponent’s one or two-yard line.
Because I love visuals here’s another – a heat map to better illustrate the average fantasy points scored by type and location of opportunity:
Higher numbers (green) indicate more fantasy points are scored on average (0.5 PPR scoring).
The heatmap illustrates that as a player gets closer to the end zone (from top to bottom), they generally average more fantasy points. Obviously, touchdowns play a large part in this because they are scored at a higher rate. That is, of course, unless your name is C.J. Spiller or “one of those backup Bills RBs.” Also illustrated in that heatmap is that targets are a more valuable opportunity type than rush attempts.
So why do we need OI?
What you just read was a proof of concept as to why the quality of the opportunity needs to be a part of the conversation anytime you talk about a player’s opportunity. However, the most persuasive argument is when you can see how much better OI relates to fantasy scoring vs. just raw opportunity totals. Below I charted fantasy points per snap on the y-axis and then alternated between OI and opportunities per snap on the x-axis for all four positions. The goal here is to show you how much better related OI is to fantasy points per snap than opportunities per snap is.
To measure these relationships I used r-squared, which in layman’s terms tells us how well variable x and variable y are related on a 0 to 1 scale. The closer to 1 the stronger the relationship. The table below shows how the r-squared values change between opportunity per snap (not weighted) and my OI rating (weighted).
|R2 Values||Opp/Snap||OI||% Diff|
As you can see, OI performs better across the board averaging 25% better among the three skill positions and a whopping 135% at the quarterback position. Case closed.
A new metric is born
So let’s summarize what we’ve read here since it’s admittedly been a lot to digest.
- OI incorporates both the quantity and quality of opportunity.
- OI is proven to have a better relationship to fantasy points per snap than opportunities per snap.
- OI can prevent you from getting sucked into the dreaded internet stat hole.
This metric is worth its weight in gold mainly for of bullet #3 alone.
Before I leave you, I put together a Google Sheets document with 2015 stats which we will be sharing soon. Opportunity Index will be an exclusive article for Gridiron Experts members in 2016, I can’t wait!
George has been playing fantasy baseball since he was a kid, filling out every Sporting News salary league card, but never sending one in due to his lack of a checking account. He still remembers the time he spot-started Storm Johnson and got a rushing TD out of it. Never forget.