I read every comment top to bottom. Skimming is for sissies! The 3.5 “turnover” penalty makes perfect sense now that I understand the context, and glad to hear I’m not the only one questioning those EP figures. It’s a damn shame Brian Burke sold out to ESPN, because as far as I know his work has disappeared from the public eye. I don’t know that we’ll ever settle on one version of EP or WP, and given the yearly variations in the NFL environment, it seems all but impossible to nail it down anyway.

Adam – wow, thanks for reading that whole thing…I didn’t think anyone would look at it, was mostly doing it to set myself straight on what I was thinking.

Regarding the 3.5-point TD: I believe you’re making the comment that it doesn’t seem right in reference to the fact that we normally consider a TD to be worth 7 points (PFR), 6.8 points (Romer I think) or 6.28 (Burke, when the LOS after kickoff was the 27-yard line). What I’m talking about is what is gained on the actual play. A TD score from the 1-yard line doesn’t “gain” 7 points per the linear model (or the EP model for that matter), it gains 7 (or whatever) minus the value at the opponent’s 1-yard line. So yes, the actual scoring of the TD is far less than 7. This is where the 20-yard TD bonus comes from in the linear model: you have the yards gained on the play, then you have the TD itself, which is 7 minus 5.5 – the value, in our model, at the opponent’s goal line.

OK, how do we explain this using 7 points for the TD and 3.5 for the turnover? Check it out:

Let’s say you’re on the opponent’s goal line, and then score a TD. You gain 7 points (93.3 yards) for the TD, but you lose 3.5 points (46.7) for the “turnover”. This equals 46.6 yards…this is a lot higher than our standard 20 yards. But remember, you were on the 0-yard line, so after the kick off, you’re losing 27 yards of field position (27 used to be the standard LOS after kickoff). So, now we have:

93.3 – 46.7 – 27 = 19.6, roughly 20 yards.

We can do the same thing for a touchdown play from the opposing team’s 40 yard line: you gain 7 (93.3), lose 3.5 (46.7), and gain 13 (net) yards of field position (you gained 40 on the play, getting you to the 0-yard line, then lost 27 after the kick off).

93.3 – 46.7 + 13 = 60 yards.

I know this is as goofy as it gets, but again, just trying to address your question and show where all this stuff comes from. Basically the idea is this: every drive ending state (apart from end of half/game) consists of a turnover, a field position change, and possibly points gained or lost.

Regarding the expected points on your own 38, etc. I checked that again, and the data I have from Burke does say that 1-10 from the 30 is 1.31 EP and a 4th-down from the opponent’s 30 is worth 1.06. But, your skepticism is justified, as EP data I’ve got from Keith Goldner’s Markov Drive Analysis spreadsheet, shows a different story (he has three different models, I’m using the Regressive one, don’t ask me what that means):

1-10, your own 38: 1.49 EP
4-1, opp 30: 1.77 EP
4-10, opp 30: 1.17 EP

The numbers I downloaded from Burke (this was many years ago mind you) didn’t have different EP states for varying “to-go” situations; a 4th down was a 4th down…this may be why there’s a difference. Certainly a 4th-and-1 has a higher EP than a 4th-and -10. Burke’s calculator is gone, so we can’t really check that.

In any event, more ramblings on stuff that really doesn’t matter that much, I guess. Hope you found it of interest, though Adam!