Analytics: Wisconsin Football & Expected Points Added (EPA)

I’m back with Part Nine & Ten of my Pre-Season Series: TOP 10 Wisconsin Football Stats you need to know for the 2023 Season!

Today, we will discuss what “EPA” is and who our EPA leaders are coming into the 2023 Wisconsin Football Season!

For Part 1 | Part 2 | Part 3  | Part 4 | Part 5 | Part 6 | Part 7 | Part 8

If you follow Football Analytics, I’m certain you’ve seen the term “E-P-A” thrown around or as labels in Graphs depicting top players in the NFL & CFB!

I’m here to explain what EPA is as Part 9 of this series. And then, I will share with you who the EPA leaders are for the Wisconsin Badgers heading into the 2023 Season. I’ll also dive into some deeper analytics into what can help drive EPA for our Badgers as Part 10 of this series!!

Part 9 – What is Expected Points Added (EPA):

Expected Points Added, or its shorthand acronym EPA is a metric that defines the success/failure of each Play for each Team. It derives its value from the change in “states” resulting from a Play. In its simplest form, a “state” is the Down and Distance to reach a 1st Down and the Yards to the EndZone.

Let’s use an example state.

Example:

1st Down & 10, 75 Yards To Go (Own 25YD Line)

From this “state” and the subsequent play. Say a 4-yard Rush by the Running Back it would bring us to a new “state” 2nd & 6, 71 Yards To Go. Each of these “states” has an expectation of the points a Team will score based on historic performances in that “state”. And so, EPA is the difference in those expectations, which can be POSITIVE or NEGATIVE for each team depending on the result.

Here is a graph that will really highlight this:

1. Light Blue = 1st Down
2. Dark Blue = 2nd Down
3. Orange = 3rd Down
4. Purple = 4th Down

So you can see that losing downs and being in the same Yards to Goaline position severely deteriorates your EPA. But this graph is an aggregate of all possible states for each down. So, this graph is a broad aggregation!

Going back to our example, the actual EPA of that 4-yard rush is this:

So a 4-yard Rush, actually loses the expectation for points scored by the offensive team by about 0.11 points.

Let’s say on the next play; we also have a 4-yard rush expressed as State 2 & State 3:

Again, a 4-yard Rush, loses the expectation for points scored by the offensive team by about 0.11 points. Interesting.

Let’s say on the next play, we only have a 2-yard rush, but pick up the 1st down? How will that impact the EPA?

Well, you can see that play is worth about 1.05 in EPA! But it was 2 yards less than the other two plays. Yes, but by moving the sticks and earning their team another 4 downs to continue moving the ball, that play in a vacuum was worth so much more!

Potential Issues with EPA:

But what if each play had a different ball carrier? Why would the 1st two RBs be downgraded for gaining 2 More Yards/Attempt? This represents a major potential pitfall to using EPA as a standalone metric to evaluate players because such context matters immensely, as I’ve just shown.

But if it were all one RB, say Braelon Allen. That would be 0.83 EPA over those three carries and would be about 0.28 EPA/Play.

So, over the course of a Game, Season, or Career, you would assume that these potential deviations from normalcy I presented wouldn’t have such an outsized impact. Thus, you could use the EPA metric as a way to value a Player’s Total Impact & Impact/Play.

Part 10 EPA Leaders – Wisconsin Football QB Tanner Mordecai’s EPA:

We see Tanner Mordecai is really good with 0.12 EPA/Play over his 2021-2022 Seasons at SMU. And while a majority of those games are really positive, we can see two games ironically against Cincinnati where he really struggled!

What drove his EPA/Play so low? Well, I tried to correlate some factors to it!!!

INT Rate & EPA/Play:

• Not too strong a correlation here. While there is definitely an impact on EPA by throwing INTs, there is still more to it!

TD Rate & EPA/Play:

• There is a much stronger correlation here, but is there a way to get it even tighter? I think so!

Net Big Play Rate & EPA/Play: (Net Big Play = [TD Rate – INT Rate])

• So, it’s not shocking stuff here, but increasing your TD Rate and limiting your INT Rate will skyrocket your EPA/Play as a QB!

What does that look like if Mordecai sits in the large part of this distribution and we project this correlation? It’ll look something like this:

I’d say we’d be good with any of those stat lines?? But I called out his Heisman chances in a prior post.

How do these numbers stack up?

On a 32 ATT/G Average (Longo’s Average at UNC), if Mordecai were to achieve >11% TD Rate & <3% INT Rate, he could be in that conversation. Although that would put him on the low end of the spectrum (Bryce Young 2021). But it would be Heisman Level output!

However, does 49 TDs seem very achievable? I’m going with no. But if he can keep his INT Rate below 1.75%, getting 35+ TDs would get him in that conversation!

Wisconsin Football RB’s EPA:

There was a lot of fluctuation in Braelon’s and Chez’s performance over the past two seasons! We primarily saw Allen trail off at the end of each Season, which I think we can chalk a lot of that to injury battles. With Chez, I think you can make the same argument, but only if the consistency pre-injuries were there. And I’m just not seeing it in this data!!

Which shows in this this next chart, that looks at cumulative EPA/Play over their 2021-2022 campaigns:

Here, we see Chez really suffer from an EPA/Play perspective. Could this be due to the issue I highlighted earlier, getting a lot of work on early downs and not necessarily moving the chains on those carries? Which would severely impact his cumulative EPA and thus, his EPA/Play!!

Vs. Light Boxes:

Here, we see a similar macro trend, to which I won’t push the panic button on Chez just yet! But looking at Braelon, that 0.10 EPA/Play vs. Light Boxes should have us all SALIVATING for this season because he will be gashing opposing teams if they don’t load the box!!!

Wisconsin Football WR’s EPA:

I don’t have any deeper analytics to WR EPA that I’m going to analyze so here are some cool charts to highlight this new WR Core for Wisconsin Football!

Core Six Trends:

This may be tough to read, but hopefully not. But we can see here that the two players, I think based on reports coming out of Fall Camp as well as their overall track record is Chimere Dike & Bryson Green. Both of these WRs show some real consistency in positive EPA/TGT across games!

Keontez Lewis, Skyler Bell, and Will Pauling have all shown they can be real threats with games >2 EPA/Tgt, but outside of those IMPACT games they have been relatively quiet. Especially Bell down the stretch in 2022!

The biggest unknown of this group will be C.J. Williams, the former 4-Star and Top-100 WR Prospect! Until Bryson Green’s late camp surge Williams had been taking many of the Reps with the 1’s in Spring and Fall Camp. So it must be obvious to this staff that the talent to put up numbers akin to Dike & Green is there!! Which excites me greatly!

Here is this over their 2021-2022 Campaigns:

Core Six EPA/TGT:

Dike, Green, and Lewis have contributed the most over these two seasons! But with reports out of Camp & what we know Skyler Bell can do, I would expect to see these numbers greatly improve for the bottom three on this list! This would put this group as the most talented collection of WRs Wisconsin Football may have ever had at one time.

Gone are the days when UW has 1 or maybe 2 polished WRs in the room, which should help out Tanner Mordecai immensely!

Final Thoughts on EPA & Wisconsin Football Heading Into the Season:

Look, EPA isn’t a perfect statistic. and like all things, additional context to coincide with its usage is ABSOLUTELY NECESSARY. But the idea has pushed forward our understanding of Football, at least statistically, by leaps and bounds! Or at least it has for me; I can’t speak for anyone else. It helps cut through most of the noise that is held in all these other statistics. Completion %, Stuff Rate, INT Rate, On-Target %, and the list could go on and on.

What matters in Football is SCORING POINTS and stopping your opponent from SCORING POINTS. With EPA, you can cut straight to that fact. But what other layers can you add to the analysis? Play-Action/RPO vs. Straight DB, Light Box vs. Heavy Box, Blitz vs. No Blitz, Coverage Schemes, Run-Type, all of which are ways we can slice and dice the data to an even more granular level!

This can help us as fans identify what is truly working and what isn’t! Giving us something to scream and yell about on Twitter/Facebook, Text Chains with your buddies, or at the Bar on Gameday! Which, for some, is the whole point of fandom.

So, if this is a new term for you, I’m glad to introduce you to it, and for those who have. Let’s take it a level deeper than I see it used broadly in the Football Analytics community!

As for My Final Thoughts on Wisconsin Football:

I think I’ve shared with you a rather optimistic tone throughout this Preseason Series. And it is for very good reason we have a brand new QB leading this Team who recently was Voted Captain. I remember a certain Final Year Transfer QB who was able to come in and garner that same respect! He had a pretty good year, and he didn’t even have Phil Longo…I kid.

But yes, we do have Phil Longo bringing his Air-Raid Principles, which is music to Braelon Allen and Chez Mellusi’s ears. Why is that? Well, with that scheme, they will see a considerable increase in Light Boxes, which means much larger running lanes to bulldoze their way around Camp Randall!

Not to mention the WR Transfers brought in (Green, Pauling, Williams, Burroughs), to go along with already proven WRs Dike, Lewis, and Bell! And we have ourselves one of if not THE MOST talented WR Core ever in recent Wisconsin Football history!

Then we get to the defensive side of the ball, loaded with players recruited under Jim Leonhard & Bobby April. Now coached by Mike Tressel and Colin Hitschler! Bringing in a new scheme with the 3-3-5, which has seen remarkable success against opposing passing games. However, one thing Tressel has stressed is the idea of “Meshing the Elite” which I’m assuming means fusing and combining what these players are used to with his own schemes into a blended defensive philosophy. One area we’ll be familiar with is the Dollar Package and seeing Hunter Wohler flying around the Football Field in several different positions. It’s something we saw a ton of down the stretch last season as he returned from his early season injury.

Lastly, it’s the Man that puts it all together. Luke Fickell. I’ve been extremely impressed with how he’s handled the transition. Being an outside guy and coming into this position on the back of UW’s AD Chris McIntosh firing Paul Chryst an Alum and longtime coach (Ast-HC Tenure), and passing over Jim Leonhard, a Badger Great and long-tenured coach, couldn’t have been easy. There will be doubters and haters, of which I’ve seen very little of this past month. This speaks to how he’s carried himself and set a new tone with this Program. The sneak peek videos that have been shared by Badgers Football Social accounts, where we get to witness in Raw Form how he handles business with the most important group. THE PLAYERS. Not the media, and I’ll tell you, I like what I see. Sometimes, he has ME wanting to run through a brick wall for him!

But I think that’s just my overall excitement for this Season. My expectations are extremely high. Like I said earlier…it’s for good reason!

On Wisconsin!

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