Bill Connelly takes a look at what we can learn from defensive box score stats and general rates of havoc.
17 Dec 2011
by Aaron Schatz
Last week, we published in-season numbers for receiving plus/minus. This week, we bring you in-season numbers for YAC+. Much like plus/minus, this stat creates a baseline for how much YAC we can expect off each pass based on three elements:
1) How deep the pass is.
2) Whether the pass is left, middle, or right.
3) What down the pass is, and how far it is away from the sticks.
The third element is needed because on third down, of course, teams are more likely to run patterns near the sticks that are designed specifically to get a first down. Those passes don't have as much YAC. So, for example, there's a difference between what we expect from a 15-yard pass on first-and-10 and what we expect from a 15-yard pass on third-and-15. We're not measuring the specific routes here, and there's a difference between how much YAC we can expect from a 15-yard curl and how much we can expect from a 15-yard dig. We don't have that data for each pass. Adding in down-and-distance to the baseline does help correct for this.
One thing missing right now from YAC+: There's no adjustment based on player position. Looking at these numbers, it probably makes sense to add some sort of adjustment for running backs, who have mostly above-average YAC+.
As noted last week, there are often mistakes by official scorers when it comes to PYD/YAC. These are "unofficial" stats and therefore there isn't the same pressure from the league to get them right. When the official scorers are trying to track 20 things on each play, there are going to be some mistakes. Some official scorers make more mistakes than others. Usually, we correct these mistakes in the course of game charting, and then report those fixes to the league and get the data changed in league data. One difference between this week and last week: I did go through the data and make a number of changes based on the FO game charting, even if we haven't reported those changes to the league yet.
Let's take a look at the best and worst players so far this year according to in-season receiving plus/minus. PYD is average distance in the air of passes to this player (both complete and incomplete).
|Top 16 WR in YAC+, Week 1-14 2011 (min. 40 passes)|
|Bottom 16 WR in YAC+, Week 1-14 2011 (min. 40 passes)|
|Top 10 TE in YAC+, Week 1-14 2011 (min. 25 passes)|
|Bottom 10 TE in YAC+, Week 1-14 2011 (min. 25 passes)|
|Top 10 RB in YAC+, Week 1-14 2011 (min. 25 passes)|
|Bottom 10 RB in YAC+, Week 1-14 2011 (min. 25 passes)|
14 comments, Last at 31 Jan 2012, 10:21pm by D2K