Game Probabilities - Conference Round

Game probabilities for the conference round are available at the New York Times. This week I explain why the Patriots' recent success running the ball is not so recent at all.

But to followers of advanced metrics, that is far from a surprise, as the Patriots have been mercilessly efficient on the ground for the past several years. Using success rate to measure running effectiveness provides a much more accurate picture of how the Patriots win with the run than traditional measures like total yards or even yards per carry...

...What the Patriots have figured out is how to use the running game effectively. They do not use it as a bludgeon on most first and second downs, as other teams do...

...Running backs like Adrian Peterson or Chris Johnson who are known for their occasional 80-yard breakaway touchdowns might be first-round draft picks in your fantasy league, but in the real world, I’ll take the Patriots’ running game any day.

Obligatory Manning-Brady Post...But This One Is Cool, I Promise

The risk of injury aside, it's inevitable we'll see either Manning or Brady in this season's Super Bowl. These two great players will be linked for all of football history. Even advanced stats aren't going to separate their performance from their teams'--the numbers are only the start of the conversation, not the end. But as long as the conversation is going to happen, we might as well start with the best numbers.

The interactive visualization below chart's each player's career. It's a special version of the QB viz I update weekly throughout the season. In this edition, I've selected only Manning and Brady for comparison, plus I've included postseason data.

The viz offers two unique and innovative ways of looking at each player, unashamedly stolen from the best baseball analytics site on the Web, Fangraphs. First, there is a plot of career cumulative Win Probability Added (WPA) from each QB's first year through his most recent year. It's an interesting way to compare the career trajectories of top passers because it's a cumulative chart.

Second, there is an "Nth best season" Expected Points Added (EPA) chart, which takes some thinking to understand because it's not plotted in chronological order. It plots each QB's season in order from his best EPA season through worst EPA season. It's not cumulative and because it appears to trend downward does not mean the QBs are declining. I like it because re-ordering each season makes the separation between each player's performance clear to see.

Podcast Episode 16 - Keith Goldner

Keith Goldner is back on the podcast to discuss this past weekend's divisional round playoff games. Keith is the chief analyst at Numberfire and also a regular contributor to Advanced NFL Stats. Dave and Keith begin by discussing some of the key decisions from the past weekend's playoff games, including whether Marshawn Lynch should've gone down at the one yard line at the end of the Seattle/New Orleans game, Riverboat Ron's goal line strategies and what to do when a punt is botched and the snap ends up in the end zone.

Keith reviews his lists of the regular season's most efficient quarterbacks and running backs and explains the differences between high efficiency and high success rate player performance. Dave and Keith round out the episode by previewing this weekend's AFC and NFC championship games, and Keith predicts which teams he expects to see playing for a ring in New York this February.

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Boooorrrring

If you thought this weekend's games lacked excitement and were one of the least interesting division rounds in recent memory, you'd be correct. I don't expect the NFL to provide heart-pounding, mind-bending drama every week, but it would be nice to have one of the four games in what is supposed to be the best weekend of football be in doubt  past the 2nd quarter. Maybe we were due for a letdown after a couple weeks of great games.

The Excitement Index (explained here) lets us measure how riveting a game was. Here are the average EIs for the division round games by year since 2001.

Seahawks Should Not Have Scored

I'm not going to touch Sean Payton's late field goal attempt, down eight, into the wind, with only one timeout remaining. After the miss, on the ensuing Seahawks drive, Marshawn Lynch tore down the left sideline and it appeared he was let into the end zone by the Saints. The question is, did the Saints make the right decision letting him score once the first down was achieved - and should Lynch have gone down at the 1-yard line? The answer to both of these will always be the same, and in this case, it's yes.

Lynch scored with 2:48 remaining in the game. Up by 15, kicking off to the Saints, the Seahawks had about a 99% chance of winning. The Saints would need to score, recover an onside kick, and score again just to tie.

Update: Lynch actually scored with 2:40 remaining, not 2:48 as originally listed in the play-by-play. That means that the Seahawks could have milked the entire clock as listed at the very bottom of this article.

But, what if Lynch had gone down at the one? Using the time calculator, we can see how much time the Saints would have had following a chip shot (99.7%) field goal from the 1-yard line. The Saints had no timeouts left, so we are looking at the blue line.

Game Probabilities - Division Round

Game probabilities for the division round are available at the New York Times. This week I take a look at the role of luck in the composition of the playoff field.

...the luckiest may be the Indianapolis Colts. Not only did they survive a 28-point second-half deficit in the wild-card round, but they were also the team that most overperformed statistical expectations in the regular season.

Based on the core efficiencies of passing, running, turnovers and penalties, plus the Colts’ strength of schedule, my efficiency model expected them to have between seven and eight wins. But they finished with 11, which was 3.2 more than expected.

All but 2 of the 12 playoff teams were above average in terms of beating their statistical expectations, and all but one of the surviving eight beat expectations. Although you may at first think this pattern points to an obvious flaw in the efficiency model, it turns out this is exactly what the field of statistics predicts...

Podcast Episode 15 - Alok Pattani

Alok Pattani of ESPN Stats & Info joins Dave to discuss how ESPN uses analytics across its different platforms. He talks about how ESPN's use of advanced stats has evolved during his time at the company and explains the process of getting statistical concepts from research idea to broadcast.

Dave and Alok then look at some of ESPN Stats and Info's NFL research, including a new stat that quantifies pass protection and how that correlates to defensive and offensive pass efficiency. Alok reviews his research on the discrepancy between EPA and YPG for certain playoff teams, and how the story of a team's success (or failure) can be explained by different combinations of stats.

After a brief chat about the ways to quantify offensive pace, Alok outlines out an interesting parallel between two QB's playing against each other this weekend. To close out the show, Dave and Alok look at three divisional-round rematches, and attempt to tease out what can, and can't, be learned from when the same teams played earlier in the regular season.

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Would Auburn Have Been Better Off Not Scoring a Touchdown?

Slate asked me to take a look at the possibility that Auburn would have a higher win probability had they not scored on Tre Mason's go-ahead touchdown run, and instead taken a knee at the 1-yard line with 1:19 to play. It was a difficult analysis, and required some unsatisfying assumptions, but in the end the results confidently pointed toward one conclusion.

...Nevertheless, Auburn had about an 81 percent chance of winning after Mason’s score, as teams in Florida State’s position are able to score a touchdown about 19 percent of the time. (These numbers are based on analogous situations in the NFL, though I’ve made slight adjustments for the differences in pace between college and the pros, and to include the chance of a kick return for a touchdown.)

So, the question we’re evaluating is whether having a first down at the 1-yard line would have given Auburn more than an 81 percent chance of winning. It’s a tricky question because it needs to be analyzed backwards...

(What I didn't explain in the article is that it's easiest to work backwards because the Auburn WP on 3rd down is depending on the results of a potential 4th down. And the WP on 2nd down are dependent on the potential results of 3rd down, which in turn depend on 4th down. And so on.)

For the Slate articles, I can't get away as much math and equations as I like, so here's a table of the relevant probabilities I used. It was complicated because the deeper into the goal-line series Auburn went, the lower Auburn's chances of getting the TD went BUT the lower Florida State's chances of responding went too. This edition assumes Auburn goes for it on the 4th down on what would be a single make-or-break play for championship.