I meant to do this earlier in the season but things were pretty crazy updating apps and making sure that everything was running correctly. But I have time this morning so I wanted to publish the actual Expected Points curves that the Efficiency App is based on. The Efficiency App just takes the expected fantasy value of each play, based on the line of scrimmage, and then measures the difference between the expectation and what actually happened. Let’s look at the wide receiver receiving curve for an example.
You can see that the Expected Value of a target with a line of scrimmage of the one yard line is about three fantasy points in a half PPR league (all values are based on half PPR in order to not have to keep multiple versions of these numbers). So if a target to a receiver is completed and results in a touchdown, that’s actually 6.6 points. Six points for the touchdown, one tenth of a point for the yards, and one half of a point for the reception. That play results in a positive reFPOE of about +3.6 points. However, if the same player were incomplete, it would result in zero fantasy points, which is about –3.0 reFPOE, because about 3.0 fantasy points were expected.
We then run that same calculation for all plays.
In the graphs below you will note some undulation in the curve. These are all smoothed values where my primary goal was to make sure that the values near the end zone are the most accurate. The undulation on the other side of the field is actually minor and shouldn’t penalize any one player compared to another. I also didn’t attempt to smooth out those values any more in case that they are meaningful. For instance, a WR rushing attempt looks like it has sort of a V shaped relationship with field position. Maybe that’s noise, or maybe it does reflect a lower expected value for plays that occur on the opponent’s 40 yard line. You could create a narrative (that may or may not be accurate) that says that WR rushing attempts on the other side of the field have more value because a long touchdown is possible and the defense has more field to try to defend.
Here are the rest of the curves for your reference.