New Year, New Data: Additions to the Passes and Patterns Knowledge Base

1. Abstract

An update on the developments affecting the various articles previously published in this space, covering both the analyses of other work and original research. Datasets for original research have been updated with 2018 data for both the CFL and U Sports. Previously written state of the art pieces that have seen new work in the field include a postscript to the original work to fold in the new research. Finally, original research previously done has been updated with the new data brought in.

The critical developments covered here include an American P(1D) (Pelechrinis and Papalexakis 2016b) model that shows non-linearity for 3rd down in a manner similar to that previously found in Canadian football (Clement 2018e, [g] 2018), and the development of a WP model for Canadian football (Thiel 2019).

The Whole Ten Yards: P(1D) in the CFL

1-Abstract

P(1D) values across down and distance were calculated for CFL data across down & distance. & Goal situations were separated and viewed independently. Results were compared to results obtained using the same methods on U Sports data. CFL offenses generally follow the same trends as seen in U Sports in terms of P(1D), though CFL P(1D) is consistently ~5 percentage points higher than U Sports under the same conditions. 1st down follows the same linear trend, while 2nd down shows exponential decay, with the previously discussed “Stupidity Asymptote” at 10%. However, CFL teams are markedly less willing to attempt 3rd down conversions, causing a lack of usable data points for 3rd down. For & goal situations the disparity between CFL and U Sports P(1D) does not seem to be as prevalent.

Three Downs Away: P(1D) In U Sports Football

1-Abstract

A data set of U Sports football play-by-play data was analyzed to determine the First Down Probability (P(1D)) of down & distance states. P(1D) was treated as a binomial variable, and confidence intervals were determined iteratively until convergence at the 10-10 level. For each down, fitted regression lines were added to enable discussion of overall trends with respect to distance.

Only points with a minimum N of 100 instances were considered. 1st down trended linearly, bearing only points at 5-yard intervals. 2nd and 3rd downs followed an exponential decay fit. Special attention was given to the non-zero asymptotes of these functions, and their implications towards the nature of the game. A review of & Goal data failed to provide any deeper insight.

Keep the Drive Alive: First Down Probability in American Football

1 – Abstract

An examination of the existing scholarship of First Down Probability (P(1D)) in American football. A fairly unambiguous question, this work reviews ten studies over the past 45 years, albeit mostly in the last decade. Results are generally consistent across sources that P(1D) decreases in linear proportion to distance-to-gain for 1st and 2nd downs, while different sources model 3rd down as being either a weakly fit linear relationship or a slight exponential fit.

4th down was not examined fully by any source because of insufficient data. What data points can be confidently placed seem very close to 3rd down, leading to discussion over whether 3rd down data can serve as a proxy for 4th down in decision-making models.