## What Are You Doing, Chip?

Cards on the table, I'm a huge Eagles fan. As an NFL stats nerd, I could not have been more excited for Chip Kelly to make the transition to the big leagues. While I did not expect him to immediately institute his Oregon trademarks, I did expect to see him going for it more often on fourth down, especially in situations where the numbers called for it -- and generally, making decisions to maximize the Eagles win probability.

It's four weeks into the season, and too many times I've asked my TV, "What are you doing, Chip?" Today against the Broncos, there were a couple of questionable decisions. Down 14-3, the Eagles were moving the ball very well to start the game. Vick and company strung together a 15-play drive that ended up with a 4th-and-4 from the Broncos 7-yard line. Using our Markov model, we can look at the progression of the drive:

At the seven, the expected value going for it is +2.57 EP (26% win probability). Kicking the field goal results in +2.31 EP (25% win probability). This is not a no-brainer situation, but playing against the top offense in the NFL and Peyton Manning, you know you will need to put up as many points as possible.

It gets worse though. Nearing end of the first half, down eight, Chip faced a 4th-and-6 in no-man's land at the Broncos 37. Rather than going for it, Chip took a delay of game penalty (when he had two timeouts) and punted -- which resulted in a touchback, a net gain of 22 yards. Here, the numbers are clear, as they always are in no-man's land. The expected value going for it is +0.77 EP and teams convert on 4th-and-6 at 45%. A punt results in -0.04 EP and a field goal results in +0.14 EP (although since the game was in Denver, the probability of making the 54-yard field goal would be higher than 45%). In addition, punting the ball back to Peyton Manning with over two minutes remaining is just asking for it, regardless of where he starts the drive.

At the start of the 4th quarter, after the majority of all hope was out the window, the Eagles had a 4th-and-21 from the Denver 28, down 49-13. To be clear, win probability at this point is well below 1% so no decision is really a brutal decision. But, what good does a field goal do down 36? Keep it a five-score game? If you want any of that sub-1% chocolatey goodness, you need to go for it, even on 4th-and-21 (which converts about 10% of the time).

Be smart, Chip, and do your thing. I'm still excited every time the Eagles take the field, just help us make the best decisions because everyone in the NFC East needs all the help they can get right now.

Keith Goldner is the Chief Analyst at numberFire.com - The leading fantasy sports analytics platform - and creator of Drive-By Football.  Follow him on twitter @drivebyfootball or check out numberFire on Facebook

### 12 Responses to “What Are You Doing, Chip?”

1. John Cord says:

Good stuff, Keith

2. Anonymous says:

Worst decision this week was made by John Harbaugh. It went like this:

4th and 5
Bills 6 yard line
Down by 6
4:04 left in 4th quarter

He kicks the field goal to go down by 3.
Conversion attempt WP= 0.3
Field goal attempt WP= 0.19

11% is pretty bad.

3. Brian Burke says:

Painful.

4. Unknown says:

Scratched my head on this one as well...this is the guy who tried a fake field goal in the Super Bowl.

5. Anonymous says:

When conventional media is saying this:

http://profootballtalk.nbcsports.com/2013/09/30/nfl-morning-after-this-is-the-reggie-bush-weve-been-waiting-for/

Scroll down to "Chip Kelly needs to be Chip Kelly"

You know something is wrong

6. John Black says:

Chip made the right call period end of sentence over and out. My boys and me alls agree he made the tough call and we have all played ball before unlike the people on this site so we have a better knowing of the game, no offense it is just how it is.

7. The Wizard says:

so having played the game gives you a better idea of the probabilities involved? that seems to be the mindset of Troy Aikman and others who diss the probabilities here. Bill Belichick and some others played the game too, and they understand probabilities

8. John Black says:

The Wizard, yes you make a good point that playing the game gives us a better idea of the probabilities involved; that's exactly what I have been trying to help folks recognize on this site as well too. Looks like you and I are in good company with Bill and Troy - not bad company to be in your corner foxhole with. Footballs is about heart and emotion and gut feel and strength of character and hard work and sweat and practice and stuff like that and such and not about probably and maybe and calculators and math teachers. This fantasy football thing is just a fad and wont last long. This site will call us profits a year from now for being right. It is not like I don't like these dudes on here, they are all sweet and all, but just like I have to educate fools back in the day on my local semi-pro team i'm having to educate folks now too. Thanks Wizard for backing a brother up, you know what i'm sayin

9. Jay Dennison says:

@John Black - It is clear you probably were a football player, or just an uneducated knucklehead. Either way, you completely misinterpreted the previous statement. Yes, football has a lot to do with big balls, and brotherhood, but it also has to do with playing the percentages--something that Chip Kelly succeeded in at Oregon, but something that he is failing to do in the NFL...and something that you are completely missing. Perhaps this site is a little above your head--er, heart--er, emotions--as this site is about intelligence--something you clearly lack.

10. Nathan Lazarus says:

@Anonymous
I agree that Harbaugh should have gone for that, but I think the probability of conversion on a 4th and 5 near the end zone is slightly less than the probability of converting a 4th and 5 in the middle of the field, as there's less room to work with. I don't know if this probability is less, and I don't know if the fourth down calculator takes this into account, but it seems like it's harder to spread a defense out when you're near the goal line. Do you know if this is harder Brian?

11. John Black says:

Jay, Thanks man, yes I was on a Pro football prospect track all the way through 7th grade until my bad asthma and allergies slowed me down. Sounds like there is more of us in the brotherhood that you talked about on this site then I first was thinking it was gunna be. Me, you, and The Wizard should start our own site for those who understand football is about balls and brothers like you saying. But I like these sweet nice math boys on this site too and they need people like you and me to help them understand what football is about.

12. Brian Burke says:

Yes, conversion is harder in the red zone. The calculator has 3 regions outside the redzone, from the 20-10 and inside the 10.

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